m.sc.thesis_m.hassan

South Valley University Faculty of Science (Sohag)

GEOCHEMICAL CHARACTERISTICS OF THE SURFICIAL NILE BASIN SEDIMENTS AND THEIR ENVIRONMENTAL RELEVANCE,

SOHAG AREA, EGYPT.

A THESIS Submitted to the Faculty of Science (Sohag)

South Valley University

In partial fulfillment of requirements for the degree of MASTER OF SCIENCE

(Geology)

By MOHAMED HASSAN MOHAMED ALI

B.Sc. Geology (1998)

Supervised by

Dr. Abdel Aziz A. El Haddad Ass. Prof. of Geology Geology Department

Faculty of Science (Sohag), South Valley University

Dr. Adly A. Omer Ass. Prof. of Environ. Geochemistry

Geology Department Faculty of Science (Sohag),


Dr. Mohamed S. Ibrahim Ass. Prof. of Soil Science

Soil and Water Department Faculty of Agriculture (Sohag),


2005-1426

South Valley University Faculty of Science (Sohag)

Approval Sheet Of the M.Sc. Degree

Candidate: Mohamed Hassan Mohamed Ali Title: “Geochemical characteristics of the surficial Nile basin

sediments and their environmental relevance, Sohag area, Egypt”

Degree: M. Sc. (Geology)

Supervised by

Dr. Abdel Aziz A. El Haddad Ass. Prof. Of Geology Geology Department

Faculty of Science (Sohag), South Valley University

Dr. Adly A. Omer Ass. Prof. Of Environ. Geochemistry

Geology Department Faculty of Science (Sohag),


Dr. Mohamed S. Ibrahim Ass. Prof. Of Soil Science

Soil and Water Department Faculty of Agriculture (Sohag),


Examiners: 1- Prof. Dr. Mostafa M. Soliman 2- Prof. Dr. Abbass M. Mansour 3- Dr. Abdel Aziz A. El Haddad 4- Dr. Adly A. Omer

Faculty Board Of Graduate Studies

ACKNOWLEDGMENT

Acknowledgements

I do thank ALLAH fo r g i f t s dedicated to me.

A special thank and appreciation should be paid from our group of environmental geochemistry to Prof. Dr. Abdel Mateen Moussa, President of South Valley University, for his great efforts in supporting and developing our lab facilities.

I am deeply indebted to Dr. Adly A. Omer, Ass. Prof. of environmental

geochemistry, Faculty of Science, Sohag, South Valley University, for his suggesting the research point, close supervision, critically reading and hardly correcting the manuscript. He provided a motivating, enthusiastic, and sympathetic atmosphere during the many discussions we had. I would like to give him a special thank for his kindness and broad-heart.

My special appreciation should be paid to Dr Abdel Aziz El-Hadad, Ass.

Prof. of geology, Faculty of Science, Sohag, South Valley University, for his supervision, helpful discussions, continuous encouragement and reading the manuscript.

Also, I would like to acknowledge Dr. Mohamed S. Ibrahim, Ass. Prof.

of soil science, Faculty of Agriculture, Sohag, South Valley University, for his supervision and the constructive comments during the progress of this work.

I would like to express my deepest appreciation and heartful thanks to

Prof. Dr. A. El-Shater, Head of Geology Department, Faculty of Science, Sohag, South Valley University, for his close encouragement, continuous help and providing the different facilities.

Sincere thanks to Prof. Dr. Osman El-Maghraby, Dean of the Faculty

of Science, and Prof. Dr. Abdel Mawgood Moustafa, Vice Dean of Higher Education and Research, Faculity of Science, Sohag, South Valley University, for their greatful support.

Appreciations are also extended to my colleagues and staff members of the

Geology Department, for their kind help. I am very indebted to my colleagues in the Botany Department, who helped

me during the bacteriological investigation.

Mohamed H.M. Ali

TABLE OF CONTENTS

i

TABLE OF CONTENTS

TULIST OF TABLESUT .............................................................................................................................I

TULIST OF FIGURESUT .............................................................................................................. VIII

TULIST OF APPENDICESUT.........................................................................................................................XIII

TUCHAPTER 1

UINTRODUCTION

U1.1 Background and General OutlineU.............................................................................................1

U1.2 Scope Of The Present StudyU.......................................................................................................5

UCHAPTER 2U

UGEOLOGIC SETTING AND LANDUSES U

U2.1 Geologic SettingU ..............................................................................................................................10

U2.1.1 The lower Eocene rocksU.............................................................................................................11

U2.1.1.1 Thebes FormationU.....................................................................................................................12

U2.1.1.2 Drunka FormationU...................................................................................................................12

U2.1.2 The Neogene and Quaternary depositsU..............................................................................12

U2.1.2.1 Early Pliocene depositsU ...........................................................................................................13

U2.1.2.2 Late Pliocene / early Pleistocene sedimentsU .................................................................14

U2.1.2.3 Pleistocene depositsU................................................................................................................14

U2.1.2.3.1 Qena FormationU ....................................................................................................................15

U2.1.2.3.2 Kom Ombo FormationU.......................................................................................................15

U2.1.2.3.3 Ghawanim FormationU ........................................................................................................16

U2.1.2.3.4 Dandara FormationU .............................................................................................................16

U2.1.2.4 Recent (Holocene) depositsU ................................................................................................17

U2.1.2.3.1 Alluvial depositsU ....................................................................................................................17

U2.1.2.3.2 Wadi depositsU ........................................................................................................................17

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U2.2 Landuse CharacteristicsU................................................................................................................19

U2.2.1 Cultivated floodplainU..................................................................................................................19

U2.2.2 Reclaimed landsU ..........................................................................................................................20

U2.2.3 Wadi depositsU ...............................................................................................................................20

U2.2.4 Lands applied for wastewater disposal U ...............................................................................21

U2.2.4.1 Lands applied for wastewater disposal at El-Dair U .......................................................21

U2.2.4.2 Lands applied for wastewater disposal at El-Kola U ......................................................22

UCHAPTER 3U

UMATERIAL AND METHODS U

U3.1 SamplingU ............................................................................................................................................24

U3.1.1 Soil samplingU.................................................................................................................................24

U3.1.2-Water samplingU.............................................................................................................................25

U3.2 Analytical MethodsU ........................................................................................................................26

U3.2.1 Soil analysisU ...................................................................................................................................26

U3.2.1.1 Particle size analysisU ...............................................................................................................26

U3.2.1.2 Hydrogen ion concentration (pH)U ....................................................................................26

U3.2.1.3 Inorganic carbonateU content (CaCOB3B) ..............................................................................26

U3.2.1.4 Organic MatterU (OM).............................................................................................................27

U3.2.1.5 Soil extractionsU..........................................................................................................................27

U3.2.1.5.1 Water extractionU ....................................................................................................................27

U3.2.1.5.2 Ammonium acetate-acetic acid extraction (pH=7)U.................................................27

U3.2.1.5.3 Ammonium acetate-acetic acid extraction (pH=9)U.................................................27

U3.2.1.5.4 DTPA-extractionU ..................................................................................................................28

U3.2.1.5.5 Total extractionU .....................................................................................................................28

U3.2.1.6 Cation Exchange Capacity (CEC)U ....................................................................................28

U3.2.2 Water analysisU ..............................................................................................................................28

U3.2.2.1 Hydrogen ion concentration (pH)U ....................................................................................28

U3.2.2.2 Electrical Conductivity (EC)U...............................................................................................28

U3.2.2.3 Nitrate (NOUBU3UPBU

-UPU)U...........................................................................................................................29

U3.2.2.4 Ammonia (NHUBU4UPBU

+UPU)U ....................................................................................................................29

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U3.2.2.5 Heavy metalsU.............................................................................................................................29

U3.2.2.6 Bacteriological analysisU.........................................................................................................29

U3.2.3 InstrumentsU...................................................................................................................................29

U3.2.3.1 Atomic Absorption Spectrophotometr (AAS)U ................................................................30

U3.2.3.2 Flame photometerU ...................................................................................................................30

U3.2.3.3 SpectrophotometerU..................................................................................................................30

U3.2.4 Analytical accuracyU.....................................................................................................................30

U3.2.5 Data handlingU...............................................................................................................................30

UCHAPTER 4U

UPHYSICAL AND CHEMICAL PROPERTIES OF SEDIMENTS U

U4.1 Textural CharacteristicsU ...............................................................................................................34

U4.2 The hydrogen Ion Concentration (pH)U .................................................................................42

U4.3 Inorganic Carbonate Content (CaCOUBU3UBU)U..................................................................................44

U4.4 Organic Matter ContentU (OM)..................................................................................................49

U4.5 Cation Exchange Capacity ( CEC )U ...............................................................................................55

UCHAPTER 5U

UHEAVY METALS U

U5.1 Total Metal ContentU ......................................................................................................................65

U5.1.1U UIntroductionU .................................................................................................................................65

U5.1.2 Metal distribution and variabilityU ..........................................................................................66

U5.1.2.1 IronU (Fe) ......................................................................................................................................66

U5.1.2.2 ManganeseU (Mn)......................................................................................................................70

U5.1.2.3 CobaltU (Co).................................................................................................................................75

U5.1.2.4 NickelU (Ni).................................................................................................................................79

U5.1.2.5 ChromiumU (Cr) .........................................................................................................................83

U5.1.2.6 LeadU (Pb) ....................................................................................................................................87

U5.1.2.7 ZincU (Zn).....................................................................................................................................90

iv

U5.1.2.8 CopperU (Cu) ...............................................................................................................................95

U5.1.2.9 CadmiumU (Cd)..........................................................................................................................100

U5.1.3 Statistical examinationU ..............................................................................................................115

U5.1.3.1 Correlation coefficientU ............................................................................................................115

U5.1.3.2 The anomalous metal levels: (outliers and extremes)U ................................................117

U5.1.3.3 Principal component analysis (PCA)U ...............................................................................122

U5.1.3.3.1 Metal association and sources (R-mode PCA)U ..........................................................123

U5.1.3.3.2 Inter-sample relationship (Q-mode PCA)U...................................................................127

U5.2 Metal BioavailabilityU .....................................................................................................................131

U5.2.1 Metal distribution and variabilityU ..........................................................................................131

U5.2.1.1 IronU (Fe) ......................................................................................................................................132

U5.2.1.2 Manganese (Mn)U......................................................................................................................134

U5.2.1.3 CobaltU (Co).................................................................................................................................136

U5.2.1.4 NickelU (Ni).................................................................................................................................137

U5.2.1.5 ChromiumU (Cr) .........................................................................................................................139

U5.2.1.6 LeadU (Pb) ....................................................................................................................................141

U5.2.1.7 ZincU (Zn).....................................................................................................................................142

U5.2.1.8 CopperU (Cu) ...............................................................................................................................144

U5.2.1.9 CadmiumU (Cd)..........................................................................................................................146

UCHAPTER 6U

UASSESSMENT OF THE ENVIRONMENTAL CONSEQUENCES U

U6.1 Natural Background Levels Of Heavy MetalsU.....................................................................159

U6.2 Environmental Consequences Of The Improper Wastewater DisposalU....................161

U6.2.1 IntroductionU ...................................................................................................................................161

U6.2.2 The disposal sites and nature of the problemU....................................................................163

U6.3 Soil And Groundwater ContaminationU ...................................................................................166

U6.3.1 SoilU ....................................................................................................................................................166

U6.3.1.1 Total metal contentU .................................................................................................................166

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U6.3.1.2 Bioavailable metal contentU ...................................................................................................168

U6.3.2 GroundwaterU .................................................................................................................................186

U6.3.2.1 Salinity, ammonia and nitrateU .............................................................................................186

U6.3.2.2 Heavy metalsU.............................................................................................................................190

U6.3.2.3 BacteriologyU...............................................................................................................................190

UCHAPTERU 7

UCONCLUSION AND RECOMMENDATIONS

7.1 UConclusion U................................................................................................................................194

7.2 URecommendationsU.................................................................................................................204

UREFERENCESU .............................................................................................................................205

UAPPENDICESU ...............................................................................................................................220

ARABIC SUMMARY ...............................................................................................................247

LIST OF TABLES

vi

LIST OF TABLES UTable(1):Landuses and numbers of sampling sites and the sample allotment. ........... 25 Table(2):Summary of descriptive statistics for sand, silt and clay content in

the cultivated floodplain, reclaimed lands and wadi deposits. .................... 35 Table(3):Summary of descriptive statistics for sand, silt and clay content in

lands applied for wastewater disposal at El-Kola and El-Dair. .................. 35 Table(4):Summary of descriptive statistics for pH, total carbonate and organic

matter content in the cultivated floodplain.................................................... 52 Table(5):Summary of descriptive statistics for pH, total carbonate and organic

matter content in the reclaimed lands. ........................................................... 52 Table(6):Summary of descriptive statistics for pH, total carbonate and organic

matter content in the wadi deposits.. .............................................................. 53 Table(7):Summary of descriptive statistics for pH, total carbonate and organic

matter content in lands applied for wastewater disposal at El-Kola. ......... 54 Table(8):Summary of descriptive statistics of pH, total carbonate and organic

matter content in lands applied for wastewater disposal at El-Dair. ......... 55 Table(9):Summary of descriptive statistics of the CEC in the studied landuses................. 56 Table(10):Summary of descriptive statistics for the total heavy metals content

in the cultivated floodplain .............................................................................. 104 Table(11):Summary of descriptive statistics for the total heavy metals content

in the reclaimed lands....................................................................................... 104 Table(12):Summary of descriptive statistics for the total heavy metals content

in the wadi deposits........................................................................................... 105 Table(13):Summary of descriptive statistics of the total heavy metals content

in the lands applied for wastewater disposal at El-Kola. ............................. 105 Table(14):Summary of descriptive statistics of the total heavy metals content in

the lands applied for wastewater disposal at El-Dair. ................................... 105 Table(15):Correlation coefficients of heavy metals, carbonate, organic matter

and clay content in the investigated sediments.............................................. 115 Table(16):The anomalous levels of heavy metals in the studied sediments. ................ 121

vii

Table(17):Eigenvalues, total variance and cumulative variance percentage extracted from the data set. ............................................................................. 123

Table(18):Loadings of the PCA eigenvectors for the first two components ................ 125 Table(19):Summary of descriptive statistics for the bioavailable heavy metals

content in the cultivated floodplain ................................................................ 148 Table(20):Summary of descriptive statistics for the bioavailable heavy metals

content in the reclaimed lands......................................................................... 148 Table(21):Summary of descriptive statistics for the bioavailable heavy metals

content in the wadi deposits............................................................................. 149 Table(22):Summary of descriptive statistics for the bioavailable heavy metals

content in lands applied for wastewater disposal at El-Kola....................... 149 Table(23):Summary of descriptive statistics for the bioavailable heavy metals

content in lands applied for wastewater disposal at El-Dair. ...................... 149 Table(24):The calculated background values of the total metal content for the

cultivated floodplain, reclaimed lands and wadi deposits............................ 160 Table(25):The culture enrichment factor (CEF) of the total metal content in

the lands applied for wastewater disposal. .................................................... 168 Table(26):The culture enrichment factor (CEF) of the bioavailable metal

content in the lands applied for wastewater disposal. .................................. 171 Table(27):Data of the chemical and bacteriological investigation of the

groundwater samples. ...................................................................................... 188

U

LIST OF FIGURES

viii

LIST OF FIGURES

UFig.(1):Map of Sohag showing the study area.U .............................................................. 9 UFig.(2):Simplified geological map of Sohag area.U.......................................................... 18 UFig.(3):Landuse map of the study area showing the four main landuse

sectors considered in the present study.U .......................................................... 23 UFig.(4):Map of the study area showing the soil sampling sites.U ................................... 31 UFig.(5):Index map for El-Dair and El-Kola wastewater disposal sites,

showing the soil and groundwater sampling sites.U ......................................... 32 UFig.(6):Flow chart depicting the sequence of soil analysis scheme.U............................. 33 UFig.(7):Textural characteristics of the studied sediments (gravel-free)

throughout the different landuses (Folk et al., 1970).U.................................... 38 UFig.(8):Textural characteristics of the studied sediments (gravel-free)

throughout the different landuses (USDA, 1993)U........................................... 39 UFig.(9):A box-whisker graph showing the minimum, maximum, median,

lower quartile and upper quartile of the sand fraction content in the studied sediments.U........................................................................................ 41

UFig.(10):A box-whisker graph showing the minimum. maximum, median, lower quartile and upper quartile of the silt fraction content in the studied sediments.U .............................................................................................. 41

UFig.(11):A box-whisker graph showing the minimum, maximum, median, lower quartile and upper quartile of the clay fraction content in the studied sediments.U .............................................................................................. 58

UFig.(12):Contour map showing distribution of the clay content in the surficial sediments throughout the study area.U .............................................. 58

UFig.(13):A box-whisker graph showing the minimum, maximum, median, lower quartile and upper4 quartile of the pH values in the studied sediments (<2mm).U ............................................................................................. 59

UFig.(14):Contour map showing distribution of the pH values in the surficial sediments throughout 71the study area.U ......................................................... 59

ix

UFig.(15):A box-whisker graph showing the minimum, maximum, median, lower quartile and upper quartile of the carbonate content in the studied sediments (<2mm).U ............................................................................... 60

UFig.(16):A box-whisker graph showing the minimum, maximum, median, lower quartile and upper quartile of the carbonate content in the studied sediments (<63µm).U .............................................................................. 60

UFig.(17):Contour map showing distribution of the total carbonate in the surficial sediments (<63µm) throughout the study area.U ............................ 61

UFig.(18):A box-whisker graph showing the minimum, maximum, median, lower quartile and upper quartile of the organic matter content in the studied sediments (<2mm).U......................................................................... 62

UFig.(19):A box-whisker graph showing the minimum, maximum, median, lower quartile and upper quartile of the organic matter content in the studied sediments (<63µm).U ........................................................................ 62

UFig.(20):Contour map showing distribution of the organic matter content in the surficial sediments (<63µm) throughout the study area.U ........................ 63

UFig.(21):A box-whisker graph showing the minimum, maximum, median, lower quartile and upper quartile of the cation exchange capacity in the studied sediments (<2mm).U .................................................................... 64

UFig.(22):Contour map showing distribution of the cation exchange capacity in the surficial sediments (<2mm) throughout the study area.U..................... 64

UFig.(23):A box-whisker graph showing the minimum, maximum, median, lower quartile and upper quartile of iron content in the studied sedimentsU. .............. 106

UFig.(24):Geochemical contour map showing distribution of the total iron content in the surficial sediments (<63µm) throughout the study area.U ............ 106

UFig.(25):A box-whisker graph showing the minimum, maximum, median, lower quartile and upper quartile of manganese content in the studied sediments.U .............................................................................................. 107

UFig.(26):Geochemical contour map showing distribution of the total manganese content in the surficial sediments (<63µm) throughout the study area.U .................................................................................................... 107

UFig.(27):A box-whisker graph showing the minimum, maximum, median, lower quartile and upper quartile of cobalt content in the studied sediments.U ............ 108

x

UFig.(28):Geochemical contour map showing distribution of the total cobalt content in the surficial sediments (<63µm) throughout the study area.U............. 108

UFig.(29):A box-whisker graph showing the minimum, maximum, median, lower quartile and upper quartile of nickel content in the studied sediments.U ............. 109

UFig.(30):Geochemical contour map showing distribution of the total nickel content in the surficial sediments (<63µm) throughout the study area.U............. 109

UFig.(31):A box-whisker graph showing the minimum, maximum, median, lower quartile and upper quartile of chromium content in the studied sediments.U .............................................................................................. 110

UFig.(32):Geochemical contour map showing distribution of the total chromium content in the surficial sediments (<63µm) throughout the study area.U .................................................................................................... 110

UFig.(33):A box-whisker graph showing the minimum, maximum, median, lower quartile and upper quartile of lead content in the studied sediments.U ................ 111

UFig.(34):Geochemical contour map showing distribution of the total lead content in the surficial sediments (<63µm) throughout the study area.U .......................... 111

UFig.(35):A box-whisker graph showing the minimum, maximum, median, lower quartile and upper quartile of zinc content in the studied sediments.U ................ 112

UFig.(36):Geochemical contour map showing distribution of the total zinc content in the surficial sediments (<63µm) throughout the study area.U .......................... 112

UFig.(37):A box-whisker graph showing the minimum, maximum, median, lower quartile and upper quartile of copper content in the studied sediments.U............ 113

UFig.(38):Geochemical contour map showing distribution of the total copper content in the surficial sediments (<63µm) throughout the study area.U.............. 113

UFig.(39):A box-whisker graph showing the minimum, maximum, median, lower quartile and upper quartile of cadmium content in the studied sediments.U .............................................................................................. 114

UFig.(40):Geochemical contour map showing distribution of the total cadmium content in the surficial sediments (<63µm) throughout the study areaU............................................................................................................ 114

UFig.(41):Scatter plot diagram showing the interrelation between the total heavy metals content and the main properties of the studied sediments (clay, CaCOUBU3UBU and organic matter).U ................................................ 116

xi

UFig.(42):A general classic box-whisker plot showing the conditions of the non-outlier range and the outlier and extreme levels. U ................................ 119

UFig.(43):Box-whisker graph of the total heavy metals showing the median, lower and upper quartiles, non-outlier range and outlier and extreme valuesU............. 120

UFig.(44):Values of the different eigenvalues showing that the 1UPU

stUPU and 2UPU

ndUPU

components are the most effective ones.U.......................................................... 124 UFig.(45):Loadings of the 1UPU

stUPU and 2UPU

ndUPU R-mode principal components for the

heavy metals, clay, carbonate (CaCOUBU3UBU) and organic matter (OM) contents through the studied sediments.U ......................................................... 126

UFig.(46):Loading of the 1UPU

stUPU and 2UPU

ndUPU Q-mode principal components for the

studied sediments. Heavy metals, clay, carbonate and organic matter are the considered variables.U................................................................ 129

UFig.(47):A box-whisker graph showing the minimum, maximum, median, lower quartile and upper quartile of bioavailable iron content in the studied sediments.U .............................................................................................. 150

UFig.(48):Distribution of the bioavailable iron content in the study area. ................... 150U

UFig.(49):A box-whisker graph showing the minimum, maximum, median, lower quartile and upper quartile of bioavailable manganese content in the studied sediments.U ..................................................................... 151

UFig.(50):Distribution of the bioavailable manganese content in the study area. ............. 151U

UFig.(51):A box-whisker graph showing the minimum, maximum, median, lower quartile and upper quartile of bioavailable cobalt content in the studied sediments.U........................................................................................ 152

UFig.(52):Distribution of the bioavailable cobalt content in the study area................. 152U

UFig.(53):A box-whisker graph showing the minimum, maximum, median, lower quartile and upper quartile of bioavailable nickel content in the studied sediments.U........................................................................................ 153

UFig.(54):Distribution of the bioavailable nickel content in the study area. ................ 153U

UFig.(55):A box-whisker graph showing the minimum, maximum, median, lower quartile and upper quartile of bioavailable chromium content in the studied sediments.U ................................................................................... 154

UFig.(56):Distribution of the bioavailable chromium content in the study area. .............. 154U

xii

UFig.(57):A box-whisker graph showing the minimum, maximum, median, lower quartile and upper quartile of bioavailable lead content in the studied sediments.U ............................................................................................... 155

UFig.(58):Distribution of the bioavailable lead content in the study area. ................... 155U

UFig.(59):A box-whisker graph showing the minimum, maximum, median, lower quartile and upper quartile of bioavailable zinc content in the studied sediments.U........................................................................................ 156

UFig.(60):Distribution of the bioavailable zinc content in the study area. ................... 156U

UFig.(61):A box-whisker graph showing the minimum, maximum, median, lower quartile and upper quartile of bioavailable copper content in the studied sediments.U........................................................................................ 157

UFig.(62):Distribution of the bioavailable copper content in the study area. .............. 157U

UFig.(63):A box-whisker graph showing the minimum, maximum, median, lower quartile and upper quartile of bioavailable cadmium content in the studied sediments.U ................................................................................... 158

UFig.(64):Distribution of the bioavailable cadmium content in the study area. .......... 158U

UFig.(65):Schematic cross section showing the land applied for wastewater disposal at El Dair and the subsurface sediment layers. Percolation of wastewater into the groundwater is displayed.U .......................................... 164

UFig.(66):Schematic cross section showing the land applied for wastewater disposal at El Kola and the subsurface sediment layers. Percolation of wastewater into the groundwater and the nearby surface water is displayed. U........................ 165

UFig.(67):Geochemical maps showing the spatial distribution of the total heavy metal content at El-Dair.U........................................................................ 172

UFig.(68):Geochemical maps showing the spatial distribution of the total heavy metal content at El-Kola.U ....................................................................... 176

UFig.(69):Geochemical maps showing the spatial distribution of the bioavailable heavy metal content at El-Dair.U.................................................. 179

UFig.(70):Geochemical maps showing the spatial distribution of the bioavailable heavy metal content at El-Kola.U ................................................. 183

UFig.(71):The TDS, Nitrate and Ammonia in groundwater at El Dair and El Kola.. ......... 189U

UFig.(72):The total and faecal coliform in groundwater at El Dair and El Kola.............. 192U

UFig.(73):Map of Sohag area showing the wastewater disposal sites.U .......................... 193

LIST OF APPENDICES

xiii

LIST OF APPENDICES UAppendix (A): Selected physical and chemical properties of the examined

sediments.U ................................................................................................... 220 A-1: Cultivated floodplain (topsoil layer) .......................................................................................220

A-2: Cultivated floodplain (subsoil layer).......................................................................................221

A-3: Reclaimed lands (topsoil layer)................................................................................................222

A-4: Reclaimed lands (subsoil layer) ...............................................................................................223

A-5: Wadi deposits.............................................................................................................................224

A-6: Lands applied for wastewater disposal at El-Kola................................................................224

A-7: Lands applied for wastewater disposal at El-Dair. ...............................................................225

Appendix (B): Data of the soluble and available major cations and CEC values in the examined sediments............................................................ 226

B-1: Cultivated floodplain (topsoil layer) .......................................................................................226

B-2: Reclaimed lands (topsoil layer)................................................................................................227

B-3: Wadi deposits.............................................................................................................................228

B-4: Lands applied for wastewater disposal at El-Kola................................................................228

B-5: Lands applied for wastewater disposal at El-Dair ................................................................229

Appendix (C): Data of the total heavy metals content in the examined sediments .................................................................................................... 230

C-1: Cultivated floodplain (topsoil layer) .......................................................................................230

C-2: Cultivated floodplain (subsoil layer).......................................................................................231

C-3: Reclaimed lands (topsoil layer)................................................................................................232

C-4: Reclaimed lands (subsoil layer) ...............................................................................................233

C-5: Wadi deposits.............................................................................................................................234

C-6: Lands applied for wastewater disposal at El-Kola................................................................234

C-7: Lands applied for wastewater disposal at El-Dair. ...............................................................235

xiv

Appendix (D): Correlation coefficients of heavy metals, carbonate, organic matter and clay content throughout the various landuses. ................. 236

D-1: Cultivated floodplain ................................................................................................................236

D-2: Reclaimed lands.........................................................................................................................236

D-3: Wadi deposits.............................................................................................................................237

D-4: Lands applied for wastewater disposal (ponds and wetlands). ...........................................237

D-5: Lands applied for wastewater disposal (farmlands) at El-Dair. .........................................238

Appendix (E): The principal component scores of the first two factors

throughout the studied sediments. .......................................................... 239 E-1: Cultivated floodplain ................................................................................................................239

E-2: Reclaimed lands.........................................................................................................................240

E-3: Wadi deposits.............................................................................................................................241

E-4: Lands applied for wastewater disposal at El-Kola................................................................241

E-5: Lands applied for wastewater disposal at El-Dair ................................................................242

Appendix (F): Data of the bioavailable heavy metals content in the examined sediments. ................................................................................................... 243

F-1: Cultivated floodplain.................................................................................................................243

F-2: Reclaimed lands .........................................................................................................................244

F-3: Wadi deposits .............................................................................................................................245

F-4: Lands applied for wastewater disposal at El-Kola ................................................................245

F-5: Lands applied for wastewater disposal at El-Dair ................................................................246

CHAPTER 1 INTRODUCTION

INTRODUCTION

1

CHAPTER 1 INTRODUCTION

1.1 Background and General Outline The earth is the only planet possessing the conditions necessary to support

life, and it is the only home of human and other organisms. The ground beneath our feet is fundamental to our daily life; it provides us the water we drink and the food we eat. Geology, as the science of studying the earth as a whole, is thus considered an important part of the environment wherein we live.

Our environment is a combination of both natural conditions (geological

and biological) and the human (anthropogenic) interferences. The environment in a given area is influenced by the interaction between the natural conditions (geogenic) and anthropogenic activities. Geological information is urgently needed in the society to understand and evaluate the adverse impact of the environmentally effective activities including agricultural, industrial, urbanization and wastewater disposal. Damage to the environment can frequently be avoided if geological knowledge is available and utilized. If the environmental damage has already occurred, then geological knowledge may contribute to restricting and mitigating hazards of such damage.

The interaction between the different geologic materials is important for the

biosystem and human health. The health of plant, animals and man is strictly affected by the amount and properties of chemical elements available from the geologic media. Chemical elements are the building blocks of the different earth’s systems: the geosphere, the hydrosphere, the atmosphere and the biosphere. Understanding the sources, distribution and behavior of chemical elements in the earth’s systems is therefore of essential importance to evaluate their influence on the biosystem.

INTRODUCTION

2

TThe distribution of chemical elements over the earth’s surface, however, is not random but is controlled by physicochemical parameters that are increasingly well understood as a result of progress in geochemistry. Geochemistry, in its broadest sense, is concerned with understanding the abundances and distribution of chemical elements in the different geologic media of the earth (e.g. rocks, sediments, soils and water) and discovering the principles governing this distribution.

At first glance, it may be seen that there is little connection between the

composition of rocks and the health of organisms (human, animal and plant). In fact, the direct relation between the compositional characteristics of geologic material and health of the various biota is evident. A scientific field has been arisen to involve the study of the interaction between the natural chemical elements throughout the various geologic media (e.g. rocks, soil, surface water and groundwater) and quantify their impact on the biosystem in general and human health in particular. This field, generally referred to as environmental geochemistry, plays a significant role in understanding the geogenic and anthropogenic environmental contributions to the biosystem and human health. Hence, direct link between geochemistry and health was documented. Environmental geochemistry depends on the interaction between geology, chemistry and biology to provide information essential to the environmental management, planning and health protection (Thornton, 1995; Knight and Klassen, 2001). Environmental geochemistry developed, in a large part, in response to the need for understanding the behavior of chemical elements in surface water, groundwater and soils; an increase in the general awareness of the pollution status can be achieved. The possible regulations and arrangements can be accordingly recommended.

Environmental geochemistry illustrates the importance of using geological

data in environmental work and landuse planning, where it concerns with complex interactions in the system rock-water-air-life to give rise a wide range of chemical elements in the surface environment. The naturally occurring chemical elements are not distributed evenly across the surface of the earth. However,

INTRODUCTION

3

environmental problems can arise when element abundance is too low (deficiency) or too high (toxicity). The inability of the environment to provide the correct chemical balance may lead to serious health problems.

A group of the naturally occurring chemical elements are known to be

essential nutrients for humans, animals, plants and microorganisms, where they play an important role in their growth and development. Most of these elements do occur in the body as they do in rocks, but only at very low concentrations. Many of the chemical elements are considered to be potentially toxic to a wide range of organisms and, moreover, some are toxic even at very low concentrations. Some metals are described as xenobiotics, i.e., they have no biological function or useful role in the human physiology but they are generally toxic even at trace levels of exposure (Mertz, 1986; WHO, 1996).

The earth’s rocks are the ultimate source of chemical elements in the

environmental media and the human body (Montgomery, 1986). The concentrations of trace elements in rocks vary by rock type, which is a fundamental control on their availability.

The trace element concentrations in the environment are modified by a

variety of natural processes as well as the accidental human activities. Rocks weather into soil, causing mobilization of chemical elements into the environment. These chemical elements are recycled within the environment and ultimately reach the human body, directly or indirectly. The water we drink contains trace elements leached from rocks and soil and may be polluted from the various human activities. The air we breath is another source of trace elements outgassed from the earth, released during volcanic eruptions or added through pollution from the different emissions.

The health problems associated with the geological environment are

acutely felt in the developing countries due to the added burden of poverty and malnutrition. Most of the people in these countries depend on local sources of food and water, so that any local geochemical anomaly can have a notable

INTRODUCTION

4

negative effect on the populace. By contrast, the inhabitants of developed nations can include pollutants within their foods that come from different parts of the world. Within the last few centuries, the idea that geology might be related to health was initially suggested by the geographic correlation. The frequency of a certain disease has seemed to vary geographically, to be more common in some places than others.

The frequent coincidence of distinctive chemical characteristics of rocks or

soil with the distribution of a certain disease, suggested that the two might be related. It was reported many years ago that the incidence of a certain health problem in a local area is related to excess, deficiency or chronic poisoning of some trace elements. Geochemists have been studying the link between geology and health for over the last decades (e.g. Nriagu, 1981; Bowie and Thornton, 1985; Thornton, 1986; Thornton, 1988; Lag, 1989; Fergusson, 1990; Appleton et al., 1996); the matter which is still growing up dramatically.

The scientific discipline dealing with the interrelation between geology and

health is internationally termed as medical geology; an equivalent term is locally used in the Nordic countries as geomedicine. Medical geology is focused on the relation between the environmental factors and health and discusses the geographic distribution of the different health problems, as controlled by the geoenvironmental conditions.

Pollution of the environmental media by heavy metals and trace elements

can arise from various sources, which may be natural or anthropogenic. Human activities have drastically altered the biochemical and geochemical cycles and the balance of some heavy metals. Heavy metals are stable and persistent environmental contaminants since they cannot be degraded or destroyed. Therefore, they tend to accumulate in the surficial environment including soils and sediments. Since metals are ubiquitous in time and space, their adverse effects on the human health is most probable.

INTRODUCTION

5

In general, the anthropogenic sources of heavy metals and trace elements in the environment can be categorized into point and non-point (Mattigod and Page, 1983; TEP, 2002). Point source means any discernible, confined and discrete conveyance. This means that, point source pollutants enter the geologic media at an easily identifiable distinct location through a direct route. Discharge from point sources of pollution is often continuous and easier to identify, measure and control. Non-point source pollution is the introduction of impurities into a surface environment, usually through a non-direct route and from sources that are diffuse in nature. Generally, non-point sources cannot be monitored at their original site, and their sources are not readily traceable. Both point and non-point sources of pollution can result from various natural processes and anthropogenic activities.

In Egypt, there is little systematic information on the geographic

distribution of chemical elements, particularly the potentially toxic ones, in the geological media. Of primary interest is the risk arising from the environmental pollution by heavy metals. A serious program aiming to archiving information and database on the levels of heavy metals and their distribution pattern in the geoenvironmental media is urgent. So, the interrelation between the epidemiological information and the metal levels in the environment can be discussed. Accordingly, the actual reasons of the widely distributed environmental diseases will be available. The appropriate procedures and regulations to mitigate the problem and protect the human health and ecosystem can be then achieved.

1.2 Scope Of The Present Study The study area is represented by the Nile basin stretch extending between

latitudes 26P

°P 24P

′P 16P

″P and 26P

°P 36P

′P 16P

″P and bordered from both the east and west by

the higher relief Eocene limestone plateau; Sohag city is situated in the middle of the area (Fig.1). The present study deals with the geochemical characteristics of the surficial Nile basin sediments in the study area aiming to quantify their environmental relevance. As a principal manner, the geologic setting of the Nile

INTRODUCTION

6

basin sediments in the study area was reviewed. The surficial sediments distributed in the area were differentiated into four main sectors of various landuses. These are:

• The cultivated floodplain, • The reclaimed lands, • The wadi deposits, and • The lands applied for wastewater disposal.

The physical and chemical properties of sediments and soils play an

essential role in controlling their ability for sorption and desorption of heavy metals. The environmental impact of sediments and soils is largely influenced by their physical and chemical properties including:

• The textural characteristics, • The hydrogen ion concentration (pH), • The inorganic carbonate content (CaCOB3B), • The organic matter content (OM), and • The cation exchange capacity (CEC).

Accordingly, the mentioned physical and chemical properties of the studied sediments were estimated and quantified.

In the study area, two sites (El-Kola and El-Dair) are used for the wastewater disposal. It was found that wastewater is improperly disposed of causing disastrous environmental impact. So, a special attention was given to study these sites in more detail in order to quantify the adverse environmental effect of such practice. Sites displaying elevated levels of heavy metals were determined and geochemically mapped. The environmental consequences of the wastewater disposal were evaluated and discussed.

The main objective of the current study is directed to evaluate the

distribution levels of the total heavy metals and their bioavailability in surficial sediments from the study area. Identifying the possible sources of heavy metals and discussing their probable environmental impact is a main objective. Dissemination of scientific database on background concentrations of chemical elements is necessary for the environmental monitoring, remediation of

INTRODUCTION

7

contaminated sites, landuse planning, and ecological evaluation. Reliable and comprehensive information about the background levels of chemical elements in the surficial sediments will facilitate scientifically defensible decisions by the policy makers. Data on the background levels of heavy metals in the surficial sediments in Sohag area are extremely limited. Such data are necessary to evaluate the contamination from either natural or anthropogenic sources.

Two hundreds and twenty six samples were collected from the different

surficial sediments throughout the main four landuses of the study area. The soil samples were subjected to the various physical and chemical analyses.

The total and bioavailable concentrations of the heavy metals (Fe, Mn, Co,

Ni, Cr, Pb, Zn, Cu and Cd) were determined in the surficial sediments throughout the study area. In general, geochemical mapping provides a mean of defining the spatial distribution of chemical elements in a certain area to be a vital guide for the officials concerned with the environmental issues. Geochemical maps are then required in order to document the current state of chemical elements at the surface environment and to provide a datum against which the future contribution can be estimated. So, the distribution pattern of the considered metals was displayed using the appropriate geochemical mapping technique.

Data base on the natural levels of heavy metals in the uncontaminated sediments and soil serves as a starting point to evaluate metal pollution risks in a given area. Determination of natural background levels of heavy metals in the surficial sediments of the study area is therefore a vital objective. The range of background levels of heavy metals in the uncontaminated sediments was statistically evaluated.

The extent of contamination of sediments and soil by heavy metals was

assessed by comparing the metal content with the Maximum Allowable Limit (MAL) used for the worldwide soils. The anomalous levels of the concerned metals were statistically estimated. The inter-variable relationship and the possible factors controlling their behavior were statistically quantified using the

INTRODUCTION

8

R-mode factor analysis. Loadings of the 1P

stP and 2P

ndP factors differentiated the

metals into four distinctive geochemical trends reflecting their possible related sources:

• Clay trend (geogenic), • Carbonate trend (geogenic), • Organic matter trend (anthropogenic), and • Mixed trend.

In addition, the inter-sample relationship was statistically evaluated using

the Q-mode factor analysis. The examined samples representing the study area were distinctively loaded on the stated geochemical trends. So, the main factors controlling the levels and distribution pattern of the estimated metals can be quantified. Also, the natural composition and anthropogenic activities influencing the behavior of these metals can be determined.

INTRODUCTION

9

Fig. (1): Map of Sohag showing the study area.

CHAPTER 2

GEOLOGIC SETTING AND

LANDUSES

GEOLOGIC SETTING AND LANDUSES

10

CHAPTER 2 GEOLOGIC SETTING AND LANDUSES

2.1 Geologic Setting The River Nile, the longest river in the world, is draining northeast Africa

from south of the equator northward to the Mediterranean Sea. The Nile receives its water from the tropical headwaters in central Africa and Ethiopia. Egypt, the downstream country, is located in an arid climatic zone and depends completely on water from the Nile. The livelihood and stability of the Egyptians are absolutely linked to the Nile since the ancient times. The Egyptian civilization has been sustained by the Nile. The Egyptians are therefore concentrated along the Nile Valley and delta that account only for less than 5% of the total land area.

Sohag Governorate is located in the Upper Egypt occupying a major

section (about 125 km long) from the Nile Valley (Fig.1) with an average width varying from 16 to 20 km. The study area covers the middle sector of Sohag province extending between latitude 26P

°P 24P

′P 16P

″P and 26P

°P 36P

′P 16P

″P. In general, the

geology and geological evolution of the Nile Valley in Egypt have been discussed by many authors (e.g. Said, 1975, 1981, 1983, 1990; Issawi et al., 1978; Paulissen and Vermeersch, 1987; Issawi and McCauley, 1992; Omer, 1996; Omer and Issawi, 1998).

The Egyptian segment of the Nile Valley is occupied by a buried canyon

that has been carved during the Late Miocene desiccation of the Mediterranean and subsequently filled with sediments (Said, 1981). These sediments are represented principally by different varieties of clastics accumulated during the successive stages of the Nile evolution since its initiation. These deposits have different source provenances and accumulated under various depositional and climatological conditions. Consequently, the sequence of events for the geological history of the Nile basin could be established from the lithological and compositional characteristics of these sediments (Omer, 1996).


11

The lithostratigraphic setting of these sediments has been studied in details by many authors (e.g. Chumakov, 1967; Amer et al., 1970; El-Naggar, 1970; Said, 1971 and 1993; Omara et al., 1973; Issawi and McCauley, 1992; Omer, 1996; Omer and Issawi, 1998). The various rock units distributed in Sohag area (Fig.2) are composed wholly of sedimentary succession ranging in age from Lower Eocene to Recent; the main units can be summarized in the following table.

Age Formation

Wadi deposits Recent (Holocene) Alluvial deposits

(Nile floodplain) Dandara

Ghawanim Kom Ombo

Pleistocene

Qena Late Pliocene /

Early PleistoceneIssawia

Neo

gene

and

Q

uate

rnar

y

Early Pliocene Muneiha Drunka Lower Eocene Thebes

2.1.1 The lower Eocene rocks Throughout the study area, the Nile Valley is bordered by the lower Eocene

limestone plateau (Thebes and Drunka formations) that rises to an elevation reaching up to 375 m above the mean sea level. It is considered as the oldest rock unit exposed in the study area and it is underlained by the Esna Shale (Paleocene), which is unexposed in the study area.

Although, the succession of the lower Eocene rocks exposed on both sides

of the Nile Valley is built up of carbonate rocks, yet variations in the lithology and faunal content made it possible to be divided into two rock units: the Thebes Formation at the base and the Drunka Formation at the top. Many workers have dealt with the stratigraphy of these two units (Said, 1960; Amer et al., 1970; Omara et al., 1973; Mostafa, 1979).


12

2.1.1.1 Thebes Formation

The widely used formal name (Thebes Formation) was first introduced by (1960) for the lower Eocene limestone of the Nile Valley. According to him, the type lo Said cality of the formation lies at Gabal Qurnah on the western side of the Nile facing Luxor. At the type locality, the succession overlies conformably the Esna shale. He described the Thebes Formation as massive to laminated limestone with flint bands or nodules and marl rich with Nummulites and planktonic foraminifera. Amer et al. (1970) and Said (1971), subdivided the Eocene rocks exposed between Luxor and Assiut into two formations, namely the Thebes Formation at the base and the Manfalut Formation at the top. The Thebes Formation includes the massive to laminated limestone with flint bands and concretions. Omara et al. (1973) considered the Eocene succession exposed east of the Nile between Sohag and Girga to be equivalent to the Thebes Formation. Mostafa (1979) concluded that the Thebes Formation forms the foot of the limestone scarp at the southern part at the area northeast of Sohag. The exposed part of the formation decreases gradually toward the north due to the regional gentle sloping northward.

2.1.1.2 Drunka Formation

The Drunka Formation was first introduced by El-Naggar (1970) for the carbonate succession of Gabal Drunka near Assiut. Mostafa (1979) stated that the Drunka Formation covers more than 90% of the area northeast of Sohag. So, most of the scarps in this area are mainly composed of Drunka Formation which has a wide extension outside this area. The Drunka Formation is lithologically medium to thick-bedded succession of limestone, which is highly bioturbated in some horizons. Siliceous concretions of variable sizes form frequent horizons within the Drunka Formation.

2.1.2 The Neogene and Quaternary deposits The Neogene and Quaternary deposits are represented by the Nile terraces

on the floor of the wadis and foot slope of the main limestone scarps, which are


13

exposed as a strip between the Nile floodplain and the Eocene limestone cliffs. The Neogene and Quaternary Nile basin sediments have been reviewed and classified depending on the detailed sedimentological, textural, mineralogical and geochemical investigations (Omer, 1996). These sediments have been accumulated during the different stages of the Nile evolution since its initiation as a result of a drop in the level of Mediterranean Sea in late Miocene time. The Neogene and Quaternary Nile basin deposits will be discussed briefly in the following sections.

2.1.2.1 Early Pliocene deposits

During the early Pliocene and after the reopening of the Gibraltar, the Nile Valley was flooded due to the inland invasion of the Mediterranean Sea southward and formed a long estuary from Cairo to Aswan (Chumakov, 1967). This Pliocene gulf phase resulted in the accumulation of a thick succession of estuarine sediments along the valley and the side wadis. These sediments are mainly composed of bedded brown and gray clays intercalated with thin beds and lenses of silt and fine sand. During the deposition of the upper part of these sediments, the estuarine water began to regress and riverine conditions prevailed, forming fluviatile-dominated sediments made up of sand, silt and mud intercalations (Omer, 1996). These Pliocene sediments were treated as one lithostratigraphic unit called the Muneiha Formation (Issawi et al. 1978; Omer, 1996; Omer and Issawi, 1998); these sediments are comparable to the Madmoud Formation (Said, 1981).

In the study area, Muneiha Formation is cropping out along the Nile Valley

at the vicinity of the eastern and western Eocene limestone cliffs and the dissecting side wadis. Sediments of the Muneiha Formation are sloped toward the cultivated floodplain to be covered with younger sediments.

The Pliocene sediments (Muneiha Formation) are detrital in origin and

were derived principally from the pre-existing sedimentary succession,


14

particularly the Upper Cretaceous-Lower Tertiary shales and the Eocene carbonates (Omer, 1996; Omer and Issawi, 1998).

2.1.2.2 Late Pliocene/early Pleistocene sediments

These sediments were described by Said (1971, 1975 and 1981) who divided them into two units: Issawia Formation and Armant Formation. Issawia Formation was firstly introduced by Said (1971) to describe a succession of massive rubble breccia topped by the characteristic hard red breccias. Said (1981) believed that these breccias were not deposited by running water but largely by gravity. Said (1983) again proposed that these breccias were deposited by running water during pluvial times.

On the other hand, the Armant Formation is made up of alternating beds of

locally derived gravels and fine-grained clastic rocks. The gravel beds are cemented by tufaceous material. The fine-grained clastic beds are calcareous, sandy, argillaceous, or phosphatic. In places, the so-called Armant Formation is made up of alternating pebble beds, marls and horizontally bedded travertines with plant reeds.

According to Omer (1996), the precedingly mentioned two units were

treated as one unit (Issawia Formation) where they are interfingered and contemporaneously deposited. The lithological, sedimentological, and morphological characteristics of these deposits indicate a lacustrine origin, which show lateral lithological variations between clastic facies at the lake margins and carbonate facies in the central zones. In the study area, sediments of the Issawia Formation overlay the Pliocene clays and crop out along the foot slopes of the Eocene cliffs bounding the Nile Valley and at the entrances of the side wadis.

2.1.2.3 Pleistocene deposits

The lower and middle Pleistocene riverine systems were vigorous and bed-load in nature with a copious supply of water. During this stage, thick


15

succession of gravel-sand association was accumulated along the Nile Valley. These sandy sediments were treated as Qena Formation by Said (1981). They were differentiated into three lithostratigraphic units depending upon their lithological, mineralogical and geochemical characteristics (Omer, 1996; Omer and Issawi, 1998); these are the Qena, Kom Ombo, and Ghawanim formations.

2.1.2.3.1 Qena Formation

Said (1981) used the Qena Formation for a thick succession of gravel-sand association near Qena and postulated that these sediments have deposited by a vigorous and competent river with a copious supply of water. Said (opt. cit) stated that the Qena sediments derived from sources seem to have been outside Egypt and that the Ethiopian highlands were important in the supply of these sediments.

Paulissen and Vermeersch (1987) believe that the Qena Formation is much

older and they differentiated these sediments into two main terraces separated by the Dandara Formation. Issawi and McCauley (1992) stated that the Qena sands are the main sediments of the early Pleistocene rivers, which derived their waters from within Egypt and from the Red Sea Range in Sudan.

Omer (1996) discriminated the stated sediments into three units namely

from base to top: Qena, Kom Ombo and Ghawanim formations. According to him, sediments of Qena Formation are composed of quartozose sands and gravels lacking igneous and metamorphic fragments. The mineralogical characteristics of these sediments reflect their main derivation from the Nubia sandstone widely distributed in the Eastern Desert.

2.1.2.3.2 Kom Ombo Formation

The Kom Ombo Formation has been accumulated by means of the rivers coming from the Red Sea Range and draining the uncovered basement terrain in Egypt and northern Sudan. These sediments were termed proto-Nile sediments by


16

Butzer and Hansen (1968), and considered to be belonging to the lower Pleistocene.

According to Omer (1996), Kom Ombo Formation comprises the sand and

gravel sediments containing abundant coarse fragments of igneous and metamorphic parentage derived from the Precambrian rocks of the Egyptian Eastern Desert, where the sedimentary cover was considerably removed. In the study area, these sediments are composed mainly of cross-bedded sands together with gravel interbeds.

2.1.2.3.3 Ghawanim Formation

The Ghawanim Formation was firstly introduced by Omer (1996) to include the Nile sandy sediments exhibiting the first appearance of the heavy mineral association reflecting an Ethiopian source.

Ethiopian highlands became important, for the first time, in supplying the

Nile sediments when the connection of the Egyptian Nile with the Ethiopian water took place (Omer, 1996). Wadis of the Eastern Desert were still active providing sandy sediments including abundament basement rock fragments. Lithologically, the Ghawanim Formation consists of cross-bedded fluviatile sands and gravels together with bands and lenses of conglomerates and quartzitic sandstone interbeds.

Conclusively, sediments of the Qena and Kom Ombo formations are

accordingly of non-Ethiopian source, whereas those of the Ghawanim Formation are of mixed origin.

2.1.2.3.4 Dandara Formation

During the late middle Pleistocene, the great supply of the Ethiopian water coupled with the dry phase in Egypt resulted into an exotic suspended-load river


17

depending mostly on the seasonal rainfall in Ethiopian (Said, 1993; Omer, 1996; Omer and Issawi, 1998).

Sediments accumulated during this stage (Dandara Formation) were thus

entirely derived from the upper reaches of the Nile in Ethiopia and Southern Sudan. These sediments are formed mainly from fluviatile fine sand-silt intercalations and accumulated at low-energy environment. The Dandara sediments crop out intermittently along the borders of the cultivated land in the study area particularly at the western side.

2.1.2.4 Recent (Holocene) deposits

2.1.2.3.1 Alluvial deposits

These sediments form the Nile floodplain as well as the river islands and are composed of clays and silts with sandstone intercalations. These sediments are extending on both sides of the Nile stream and bordered by the Plio-Pleistocene sediments from the east and west; they range in thickness from 2 to 10m through the study area.

2.1.2.3.2 Wadi deposits

Generally, the sporadic activities of the transverse channels led to the accumulation of flash flood deposits covering the surface of the older sediments throughout the desert areas outside the Nile floodplain. These deposits vary greatly in both thickness and texture depending upon the land morphology and the intensity and regime of the flash floods. They range in thickness from few centimeters to more than 30 meter. They are formed from the disintegrated product of the nearby Eocene carbonate, in addition to the reworked material from the pre-existing sediments. These deposits have a special attention because they represent the suitable area for the increasing reclamation activities and creating new communities and developing activities.


18

Fig. (2): Simplified geological map of Sohag area.


19

2.2 Landuse Characteristics Although various landuse characteristics are reported in the study area, the

four main landuse sectors considered in the current study will be discussed (Fig. 3):


2.2.1 Cultivated floodplain The Nile floodplain covers the area next to the river channel on both sides

and extends eastward and westward toward the desert lands. The Nile floodplain forms a relatively wide strip along the western side of the valley extending from the Nile course to the western desert areas. Contrarily, it constitutes only a very narrow strip along the eastern side and, moreover, it frequently disappears. The Nile floodplain oftenly ranges in thickness from 6 to 10m, but it becomes thinner close to the surrounding desert areas reaching down to about 2m. Sediments of the floodplain were accumulated during the annual inundation of the Nile causing deposition of fine materials before the construction of the High Dam. These sediments are composed of Holocene fluviatile deposits consisting mainly of silt and clay. The Nile floodplain represents the most important physiographic unit in the study area.

The fertility of the Nile floodplain sediments and their suitability for

agricultural practice is the main factor responsible for the stability and sustainability of the Egyptians’ livelihood along the Nile Valley since the ancient times. Unfortunately, the deposition of the fertile Nile flood silt was extremely curtailed, as a consequence of the High Dam construction, causing extensive use of chemical fertilizers and other agrochemicals to improve the soil productivity; so, addition of the various contaminants became a critical environmental problem.


20

2.2.2 Reclaimed lands In Sohag, as the general case in Egypt, the intense increase of population

has caused a critical need to expand the areas of the cultivated lands to overcome the problem of food shortage. So, widespread reclamation activities started through the last two decades aiming to cultivate the low land and barren desert zone extending between the Nile floodplain and the Eocene limestone plateau on both the eastern and western sides. This zone is occupied by calcareous and sandy sediments of low productivity status because of their low moisture capacity, low organic matter content and the poverty of essential nutrients. In order to improve the fertility of these lands and their suitability for reclamation purpose, a thin layer (20-40cm) is usually transported from the more fertile floodplain sediments to be spreaded on the land surface. Thus, the reclaimed lands include two different layers; the topsoil layer and subsoil layer. The two layers are compositionally and texturally different. As a result of the relative low fertility of these lands, a widespread use of chemical fertilizers and other amendments is required.

2.2.3 Wadi deposits As has been already stated, the desert areas between the Nile floodplain and

the Eocene limestone plateau are occupied by sediments, mainly clastics, accumulated within the Nile canyon since its initiation during Miocene time. These sediments range in age from Pliocene to Recent. However, the upper surface of these sediments is mostly covered by a thin layer of wadi deposits ranging in thickness from few centimeters up to about 30m. These deposits are composed from the disintegrated products of the Eocene carbonate on both sides. Also, a significant portion of these sediments is reworked from the nearby Neogene and Quaternary clastics. Hence, the wadi deposits are of local source and accumulated during successive stages of the local flash floods. These sediments are mainly sand in nature and contain abundant content of calcareous materials.


21

Because of the various difficulties facing the reclamation practice in this zone, as a result of the prevailing arid climatic conditions and the costed water supply, the reclamation process is getting slow. However, other developing activities including urbanization and industrial projects are being currently established through this desert zone.

2.2.4 Lands applied for wastewater disposal Recently, the disposal of wastewater from the populated centers, large

cities and towns, became an urgent objective. In Sohag, as a general case in Upper Egypt, land application is the only possible way for wastewater disposal. The plan was to use the approachable desert zone outside the cultivated floodplain for such purpose. Accordingly, eight sites have been already chosen to be destined for the projected wastewater disposal in Sohag province. These sites are Tema, Tahta, El-Maragha, El-Dair, El-Kola, El-Menshah, Girga and El-Baliana (see later in chapter 6). Of these, two sites (El-Dair and El-Kola) are currently operating and the others will be in use through the near future. The currently operating sites are situated within the study area (Fig.3) and will be considered in the present study.

2.2.4.1 Lands applied for wastewater disposal at El-Dair

The wastewater disposal site at El-Dair is located about 10km to the west of Sohag City (Fig.3). This site lies in the wadi deposits bordered by the Eocene limestone plateau from the west and the cultivated floodplain from the east. The ground surface shows a general eastward slope toward the cultivated floodplain. The area is occupied by a thick succession of sandy and gravelly Pleistocene sediments covered with a thin layer of Recent wadi deposits (sandy gravel) ranging in thickness from 1m to more than 10m (Omer, 1996). The subsurface sediments are highly porous and permeable (El-Haddad and El-Shater, 1988).


22

The source of effluent disposed into this site is the western division of

Sohag City situated on the western bank of the Nile. Although a significant

division of the wastewater is used in irrigating farmlands, the major part is

improperly disposed of in the low land areas to form large uncontrolled ponds.

2.2.4.2 Lands applied for wastewater disposal at El-Kola The wastewater disposal site at El-Kola lies about 13km east of Sohag in

the desert area enclosed between the Eocene limestone plateau from the east and

the River Nile from the west (Fig.3). Raw wastewater is currently disposed of

into El-Kola from the part of Sohag City locating on the eastern side of the Nile.

The land surface is steeply sloping westward toward the River Nile.

The whole area is occupied by thin layer of highly permeable sandy gravel

sediments, ranging from 0.5 to 8m, which rests on a thick succession of dense

and impermeable Pliocene clay. The major part of wastewater is improperly

disposed of in this site and huge wastewater ponds and wetlands have been

accumulated.


23

Fig.

(3):

Lan

duse

map

of t

he st

udy

area

show

ing

the

four

mai

n la

ndus

e se

ctor

s con

sider

ed in

the

pres

ent s

tudy

.

CHAPTER 3 MATERIAL AND METHODS

MATERIALS AND METHODS

24

CHAPTER 3 MATERIAL AND METHODS

3.1 Sampling 3.1.1 Soil Sampling

In general, the soil sampling protocol in a given area depends upon several factors including the aim of study, the required details, the general knowledge and background of similar material to be sampled, and information about the concerned area (see Taylor, 1988).

In the present study, two sampling stages were followed; the first stage

begins with a limited sampling plan to determine the parameters of interest, the variability of the important chemical parameters, and the location of hot spots, if present. From the results of the initial sampling protocol, a second sampling scheme was achieved to define more precisely the interested and attractive areas. In this way, sampling sites were proportionally distributed to collect samples representing the main landuses in the study area with respect to their geographical distribution.

Accordingly, a semisystematic sampling scenario, with an interval of about

5km, was used to cover the whole area. From the initial sampling stage, two hot spots have been reported. These are the wastewater disposal sites at El-Dair and El-Kola. Then, a second stage of dense sampling protocol was performed to study these attractive sites in more detail.

A well-constrained Global Positioning System (GPS) was used for

navigation to record the sampling sites accurately. A summary of the sampling sites and the sample allotment throughout the study area is given in table (1). The geographic distribution of the sampling sites is displayed in figures (4 & 5).


25

Table (1): Landuses and numbers of sampling sites and the sample allotment.

Landuses Sites (n) Samples (n)

Cultivated floodplain 35 70

Reclaimed lands 33 65

Wadi deposits 17 17

Wastewater disposal lands 59 74

Total 144 226

Accordingly, to the present sampling protocol, 226 samples distributed

through 144 sampling sites were collected from the concerned landuses. Regarding the cultivated floodplain, the reclaimed lands and the wastewater farmlands at El-Dair, both the topsoil (0-20 cm) and subsoil layer (20-40 cm) were considered. On the other hand, soil samples were collected from the surficial layer of the wadi deposits and wastewater ponds at El-Dair and El-Kola. The sampling procedure described by USDA (1996) was followed in the present study.

3.1.2-Water Sampling Groundwater samples were collected from the available 8 tubewells in

El-Dair wastewater disposal site. Another two samples were collected from shallow hand pumps (about 12m depth) in El-Kola disposal site. Groundwater samples were collected from either tubewells or hand pumps after adequate pumping time. Samples for heavy metal estimation were filtered through 0.45µm filters and collected in acid-washed polyethylene bottles. An aliquot from each water sample destined for heavy metal determination was acidified to pH<2 using ultrapure nitric acid (HNOB3B). For bacteriological analysis, samples were collected in sterile glass stoppered bottles containing 0.1 ml of 10% (w./v.) sterile sodium thiosulfate.


26

3.2 Analytical Methods 3.2.1 Soil analysis

The collected soil samples (n=226) were air-dried and the rock fragments and large organic matter pieces were picked out. The samples were then gently crushed to pass through a 2mm sieve. Each sample was thoroughly homogenized and gently ground by means of a plastic mortar. A portion of the <2mm fraction was split out and designated as bulk sample. The fine fraction (<63µm) was separated from the leftover portion. Both the bulk samples and fine fractions were stored in plastic bottles till further estimations. The soil samples were subjected to the subsequently mentioned physical and chemical estimations. Sample handling and analysis is schematically displayed in the flow chart given in figure (6).

3.2.1.1 Particle size analysis

The mechanical analysis of the soil samples was carried out using pipette method as described by USDA (1996).

3.2.1.2 Hydrogen ion concentration (pH) B

The soil acidity or alkalinity is a factor that has great importance concerning the chemical, biological and physical properties of the ground. The acidity (hydrogen ion concentration) was measured by means of a digital pH meter (Cole Parmer) in suspension (1 soil: 2.5 water) after 15 minutes of orbital shacking.

3.2.1.3 Inorganic carbonate content (CaCO B3B)

Inorganic carbonate was estimated by Collins Calcimeter according to Jackson (1973) and USDA (1996). The carbonate content in the soil was measured by treating the samples with HCl and the evolved COB2B was measured manometrically; then, the amount of carbonate was calculated as CaCOB3B.


27

3.2.1.4 Organic matter (OM)

The oxidizable organic carbon content was measured. It was determined according to the modified Walkely and Black method (USDA, 1996). The method uses the acid dichromate system, which relies on back titration of the unused dichromate with standard ferrous ammonium sulfate and diphenylamine as an indicator.

3.2.1.5 Soil extractions

3.2.1.5.1 Water extraction

Twenty grams of the air-dried soil sample (<2mm) were orbitally shaken (225rpm) with 100ml of distilled water for 15min. The extract was then filtered through a 0.45µm filter. This extract was used for measuring the soluble fraction of major cations (CaP

2+P, MgP

2+P, KP

+P, NaP

+P).

3.2.1.5.2 Ammonium acetate-acetic acid extraction (pH=7)

In this technique (Allen, 1989), 5g air-dried soil aliquot (<2mm) and 125ml 1M NHB4BOAC (pH=7), were shaken using an orbital shaker (225rpm) for 1hour. Then, samples were centrifuged at 3000rpm for 15 minutes and the clear supernatant was filtered through a 0.45µm filter. This extract was destined for the determination of the available calcium (CaP

2+P), magnesium (MgP

2+P), potassium

(KP

+P) and sodium (NaP

+P) in the non-calcareous soils.

3.2.1.5.3 Ammonium acetate-acetic acid extraction (pH=9)

The precedingly mentioned ammonium acetate extract (pH=7) is unsuitable for samples with carbonate content exceeding 5% (Hesse, 1998), where overestimation of CaP

2+P was recorded. Instead, ammonium acetate extract at

pH 9 is more convenient for such calcareous soils (Allen, 1989). So, the attacked carbonate content is extremely limited and the extractable CaP

2+P amount

appropriately represents its available content.


28

3.2.1.5.4 DTPA-extraction

The Diethelyne-Triamine-PentaaceticAcid (DTPA) extractions were performed following Lindsay and Norwell (1978), where 10g of ground air-dried soil sample (<2mm) was mixed with 20ml of 0.005M DTPA (pH=7.3). The suspension was orbitally shaken for 2 hours and then filtered through a 0.45µm filter. The filterate was stored at 4P

oPc till metal determination.

The current extract was used for spectroscopically estimating the bioavailable fraction of heavy metals.

3.2.1.5.5 Total extraction

The total concentration of the environmentally relevant heavy metals (Fe, Mn, Co, Ni, Cr, Pb, Zn, Cu and Cd) was determined by digesting 0.5g air-dried sample (<63µm) in Teflon beakers using a concentrated acid mixture of 3ml HNOB3B (69%), 2ml HClOB4B (40%) and 10 ml HF (40%). The total metal content was spectroscopically estimated in the current acid extract.

3.2.1.6 Cation exchange capacity

The cation exchange capacity was determined from the difference between the sum of water-soluble cations (meq/l) and their available contents measured in the ammonium acetate-acetic acid extract (Hesse, 1998).

3.2.2 Water analysis 3.2.2.1 Hydrogen ion concentration (pH) B

The hydrogen ion concentration (pH) was measured for water samples using a digital pH meter (Cole Parmer).

3.2.2.2 Electrical conductivity (EC)

Electrical conductivity (EC) was measured for water samples by means of conductivity meter (WPA cm35).


29

3.2.2.3 Nitrate (NO B3PB

-P)

The nitrate content (NOB3PB

-P) in the groundwater samples was

spectrophotometrically estimated applying the sodium salicylate method (DEWAS, 1980).

3.2.2.4 Ammonia (NHB4PB

+P)

Ammonia (NHB4PB

+P) was determined by the Nesslerization technique

described by Dewis and Freitas (1970).

3.2.2.5 Heavy metals

The concentrations of Co, Cu, Ni, Pb and Zn were spectroscopically estimated in the acidified groundwater samples.

3.2.2.6 Bacteriological analysis

The bacteriological analysis was carried out using the multiple tube fermentation technique and the MacConkey broth purple media. The most probable number (MPN) of the total coliform (incubation for 48h., at 37°C) and faecal coliform (incubation for 24h. at 44.5°C) was determined. The bacteriological investigation was performed according to APHA (1985).

3.2.3 Instruments The various analyses carried out in the present study have been achieved

in the laboratory of Environmental Geochemistry, Geology Department, Faculty of Science in Sohag, South Valley University, using the subsequently stated instruments.


30

3.2.3.1 Atomic Absorption Spectrophotometr (AAS)

A Perken Elmer 2380 and Buck Scientific 210 VGP flame Atomic Absorption Spectrophotometer (AAS) with hollow cathode lamps were utilized for the determination of Fe, Mn, Co, Ni, Cr, Pb, Zn, Cu and Cd concentrations in both the soil extracts and water samples. In addition, the magnesium content and low concentrations of calcium were measured by the same technique.

3.2.3.2 Flame photometer

Calcium, K and Na were measured by means of Jenway PFP7 Flame Photometer.

3.2.3.3 Spectrophotometer

Concentrations of nitrates (NOB3PB

-P) and ammonia (NHB4PB

+P) were

spectrophotometrically estimated using S110 spectrophotometer.

3.2.4 Analytical accuracy Concentrations of the investigated metals (Fe, Mn, Co, Ni, Cr, Pb, Zn, Cu,

and Cd) were measured by Atomic Absorption Spectrophotometer (Perkin-Elmer 2380 and Buck Scientific 210 VGP). International standard reference materials (89GOV1 and 88GLA2 from Tuebingen University, Germany) were also analyzed to verify the accuracy and precision of metal determination. The recovery rates for the estimated metals were 90-114%.

3.2.5 Data handling The obtained data have been statistically analyzed for the various statistical

parameters and graphic presentations using the STATISTICA 5 for windows (1995) computer program distributed by StatSoft Inc. In addition, the different geochemical maps have been constructed by means of the SURFER 8 program (2002) distributed by Golden Software Inc.

However, analysis of variance (ANOVA) was performed to quantify the

similarity and dissimilarity of variables among the sample groups. The significant values were considered to meet confedince level of 95%; this corresponds to the propability of 0.05 (i.e. the p-value should be <0.05 at the significant difference).


31

Fig.

(4):

Map

of t

he st

udy

area

show

ing

the

soil

sam

plin

g sit

es.

El-D

air a

nd E

l-Kol

a sit

es a

re d

ispla

yed

in fi

gure

(5).


32

Fig. (5): Index map for El-Dair (upper) and El-Kola (lower) wastewater disposal sites,

showing the soil (solid circle) and groundwater (star) sampling sites.


33

Sample

Air Dry

Representative Sub-Sample

Screen

Excluded

Fine Fraction < 63µm

Comple te AcidAttack

Organic Matter (OM)

pH( 1 soil : 2.5 water )

Texture Grade

NH4OAc Extraction

Screenthrough

2mm seive

> 2mm

Soluble Major Cations

Available Major Cations

Bioavailable Heavy Metals

CEC

Fe, Mn, Co, Ni, Cr, Pb, Zn, Cu, Cd

Inorganic Carbonate

C a, M g, K,, N a

Bulk sample < 2mm

Wate r Extraction

DTPA Extraction

Organic Matter (OM)

Inorganic Carbonate

Fe, Mn, Co, Ni, Cr, Pb, Zn, Cu, Cd

C a, M g, K, N a

< 2mm

Fig. (6): Flow chart depicting the sequence of soil analysis scheme.

CHAPTER 4

PHYSICAL AND CHEMICAL

PROPERTIES OF SEDIMENTS

PHYSICAL AND CHEMICAL PROPERTIES OF SEDIMENTS

34

CHAPTER 4 PHYSICAL AND CHEMICAL PROPERTIES OF

SEDIMENTS

The physical and chemical properties of sediments and soils have a vital role concerning the applications of environmental geochemistry. The heavy metal contents in sediments and soils are affected largely by their physical and chemical properties. They affect, directly or indirectly, the amount and nature of reactions that occur on the surfaces of their constituting particles. These reactions largely govern the mobility and immobility of the different chemical elements and, therefore, control their availability. So, examination of the soil properties is important to be considered in the present study, the matter which will be discussed in the following sections.

4.1 Textural Characteristics Soil texture describes the size distribution of individual soil particles.

Specifically, texture is defined as the relative distribution of various sized particles. The rate and extent of many physical and chemical reactions, including the sorption and desorption of elements, are governed by texture because it determines the amount of surface on which the reactions can occur. Therefore, particle size distribution can influence the level of metal concentrations in sediments and soil. Fine particles (<60µm) are more reactive and have a higher surface area than coarser material (WHO, 1982). As a result, the major part of contaminants is incorporated in the fine fraction of soil and sediments. The textural characteristics of the studied sediments throughout the considered landuses will be discussed.

Results of the grain size analysis are given in Appendix (A) and displayed

in figures (7 & 8). The summary statistics of these results are given in tables (2 & 3). In addition, a box-whisker graph showing the minimum, maximum, mean, median, lower quartile (25%), and upper quartile (75%) of the sand, silt


35

and clay fractions is shown in figures (9, 10 & 11). Because of its critical importance in the concerns of environmental geochemistry, the spatial distribution pattern of clay fraction was displayed in the contour map given in figure (12).

Table (2): Summary of descriptive statistics for sand, silt and clay content (%) in the cultivated floodplain, reclaimed lands and wadi deposits (n=70, 65 and 17, respectively).

Cultivated floodplain Reclaimed lands Wadi deposits

Depth Sand Silt Clay Sand Silt Clay Sand Silt Clay 00-20 19 61 21 48 39 14 Mean 20-40 15 59 27 78 17 5

74 21 4

00-20 16 64 20 51 37 13 Median 20-40 11 59 26 83 12 3

74 22 4

00-20 3 26 7 12 4 1 Minimum 20-40 3 14 7 25 1 1

35 3 1

00-20 63 77 44 95 82 35 Maximum 20-40 67 84 54 97 65 19

95 55 10

00-20 13 12 9 19 16 7 sd.* 20-40 14 17 13 22 18 4

18 17 3

00-20 9 53 15 38 31 9 25% percentile 20-40 6 47 15 73 3 2

67 5.5 3

00-20 23 70 25 57 49 16 75% percentile 20-40 18 74 36 95 22 6

92 27 5

*sd.=Standard deviation

Table (3): Summary of descriptive statistics for sand, silt and clay content (%) in lands applied for wastewater disposal at El-Kola (ponds and wetlands) (n=29) and El-Dair (farmlands and ponds, n=30 and 15, respectively).

El-Kola El-Dair farmlands El-Dair ponds

Depth Sand Silt Clay Sand Silt Clay Sand Silt Clay 00-20 68 28 4 Mean 20-40

60 35 5 93 6 1

67

30

4

00-20 77 21 4 Median 20-40

57 31 4 96 3 1

76

21

3

00-20 5 1 1 Minimum 20-40

15 5 1 79 1 1

4

2

1

00-20 98 90 20 Maximum 20-40

94 81 14 99 16 5

97

94

11

00-20 32 29 5 sd. 20-40

21 20 4 6 5 1

30 28 3

00-20 63 5 1 25% percentile 20-40

51 21 1 91 2 1

52

8

1

00-20 95 31 5 75% percentile 20-40

72 48 8 97 9 2

91

40

8


36

Generally, the major part of the cultivated floodplain and the topsoil layer

of the reclaimed lands are silty in nature where the silt fraction is prevailed. The subsoil layer of the reclaimed lands, the wadi deposits and the lands applied for wastewater disposal at El-Kola and El-Dair are mostly described as coarsely textured sediments, where sand is the predominant fraction (see Figs. 7 & 8).

Sediments of the Nile floodplain are entirely of fluvial origin and derived

principally from the Nile hinterlands, particularly the Ethiopian basaltic plateau (Omer, 1996 and references therein). They are mainly muddy in nature and accumulated during the successive stages of the annual Nile floods for thousands of years till the construction of the High Dam. The average rate of sediment accumulation was about 9cm per century (Ball, 1939).

The obtained results show that, the silt fraction is prevailing over the other fractions followed by clay then sand. Although, there is a wide variation in the minimum and maximum values of each textural fraction in both topsoil and subsoil samples. The silt fraction ranges between 26 and 77% (mean=61, median=64%, sd.=12) in the topsoil layer; the clay fraction varies from 7 to 44% (mean=21, median=20%, sd.=9) and the sand content fluctuates between 3 and 63% (mean=19, median=16%, sd.=13). On the other hand, the subsoil layer shows more variable content of the silt fraction ranging from 14 to 84% (mean=59, median=59%, sd.=17). The clay fraction content is relatively higher in the subsoil layer compared with the topsoil one being fluctuate between 7 and 54% (mean=27, median=26%, sd.=13); although the sand fraction content in the subsoil layer covers nearly the same range (3-67%) as the topsoil layer, its average content is relatively lower (mean=15, median=11%, sd.=14). The higher content of clay fraction in the subsoil layer may refer to the migration of such fine particles with the percolating irrigation water following the agricultural practice.


37

In general, no significant difference was reported in the textural characteristics of the Nile floodplain sediments through the eastern and western sides of the Nile. Meanwhile, the sand fraction of the topsoil layer increases adjacent to the Nile stream and also toward the desert frings on both sides of the Nile. The higher content of sand fraction near the Nile course is controlled by the natural sedimentation process. During the Nile flooding, the coarse particles are deposited close to the Nile course whereas the finer ones are accumulated far away. On the other hand, the elevated content of sand fraction near the desert frings may originate from the neighboring desert zone through the wind action.

As stated above, the reclaimed lands include two contrasted layers. The

topsoil layer (about 20cm thick) is transported by the natives from the Nile floodplain whereas the subsoil layer is considered as a natural extension of the adjacent wadi deposits. So, the two layers are texturally dissimilar, in spite of their obvious interaction. Generally, the subsoil layer is markedly coarser than the topsoil one. The content of the sand fraction in the subsoil layer (mean=78, median=83%, sd.=22) is considerably higher than that of the topsoil layer (mean=48, median=51%, sd.=19). On the contrary, the silt and clay contents are strikingly elevated in the topsoil layer (mean=39 and 14, median=37% and 13%, sd.=19 and 16, respectively) relative to the subsoil layer (mean=17 and 5, median=12% and 3%, sd.=18 and 4, respectively). No significant difference was observed in the textural characteristics of the topsoil layer through the eastern and western sides of the valley. A pronounced variability was noticed in the texture of the subsoil layer between the eastern and western sides, where elevated content of silt and clay fraction is reported in the former. Such higher level of the fine fraction in the subsurface layer along the eastern side of the valley may be attributed to the effect of the nearby finely textured Pliocene clay.


38

Fig. (7): Textural characteristics of the studied sediments (gravel-free) throughout the

different landuses (Folk et al., 1970).


39

Fig. (8): Textural characteristics of the studied sediments (gravel-free) throughout the

different landuses (USDA, 1993).


40

Regarding the textural characteristics of the wadi deposits, they are described as coarsely textured sediments where the sand fraction is predominant being range from 35 to 95% (mean=74, median=74%, sd.=18). The silt content varies from 3 to 55% (mean=21, median=22%, sd.=17) whereas the clay fraction, the least fraction, ranges between 1 and 10% (mean=4, median=4%, sd.=3). It is important to mention that the amount of the silt fraction in the wadi deposits along the eastern side of the Nile Valley is considerably higher than that of the western one. Again, such elevated content of silt fraction is referred to the influence of the adjacent Pliocene fine grained sediments.

With respect to the particle distribution in the lands applied for wastewater

disposal at El-Kola, the sand fraction is prevailed over the other size fractions in most samples being fluctuates between 15 and 94% (mean=60, median=57%, sd.=21). The silt fraction is the second in abundance and it ranges between 5 and 81% (mean=35, median=31%, sd.=20). The clay fraction, the least fraction, ranges between 1 and 14% (mean=5, median=4%, sd.=4). The obtained results are strongly similar to those of the adjacent wadi deposits where both are coarsely textured grade and include considerable content of the silt fraction. This indicates that the wastewater disposal practice had no important effect on the soil texture grade. Only few samples display elevated content of fine fraction reflecting accumulation of fine particles carried by the disposal wastewater; these samples represent waterlogged sites.

Considering the wastewater disposal ponds at El-Dair, the particle size

distribution shows that the sand fraction is prevailed over the other size fractions in most samples (mean=67, median=76%, sd.=30). Although, some samples are extremely depleted in their sand content reaching down to 4%. Also, the silt fraction displays a wide range fluctuating between 2 and 94% (mean=30, median=21%, sd.=28); but it follows the sand fraction in most samples. The clay content is the least abundant fraction where it is extremely depleted in most sites (mean=4, median=3%, sd.=3).


41

Sand

(%)

1

5

10

50

100

1 2 3 4 5 6 7

1- Cultivated floodplain (topsoil)2- Cultivated floodplain (subsoil)3- Reclaimed lands (topsoil)4- Reclaimed lands (subsoil)5- Wadi deposits6- Wastewater disposal site at El-Kola7- Wastewater disposal site at El-Dair

MaxMin75%25%Median

Fig. (9): A box-whisker graph showing the minimum, maximum, median, lower quartile

(25%) and upper quartile (75%) of the sand fraction content (%) in the studied sediments.

Silt

(%)

0

20

40

60

80

100

1 2 3 4 5 6 7

Fig. (10): A box-whisker graph showing the minimum, maximum, median, lower quartile (25%) and upper quartile (75%) of the silt fraction content (%) in the studied sediments. See figure (9) for explanation.


42

The topsoil layer of the wastewater farmlands at El-Dair possesses textural properties very akin to that of the wastewater ponds. The sand fraction ranges between 5 and 98% (mean=68, median=77%, sd.=32). The silt fraction in these sediments varies from 1 to 90% (mean=28, median=21%, sd.=29), whereas the clay content ranges from 1 to 20% (mean=4, median=4%, sd.=5). On the other hand, the subsoil layer of these farmlands is markedly coarser with the sand fraction fluctuating between 79 and 99% (mean=93, median=96%, sd.=6). The silt and clay fractions are considerably depleted in these sediments (mean=6 and 1, median=3% and 1%,, sd.=5 and 1, respectively).

The abnormal elevated content of silt fraction in few samples from the

wastewater ponds and the topsoil layer of the farmlands at El-Dair, reaching up to 94%, may reveal the occasional accumulation of fine particles carried by wastewater. This may be referred to the long term of wastewater disposal at El-Dair site.

As a general consideration, the textural characteristics of sediments in the

wastewater disposal sites at El-Dair and El-Kola did not change appreciably by the wastewater disposal practice; the matter which may need longer time. El-Shabassy et al. (1971) reported that no marked change in soil texture was reported as a result of sewage effluent practice for 50 years in El-Gabal El-Asfar farm. Also, comparable results were reported by Bayoumi et al. (1993) to indicate that the variation in soil mechanical fractions from wastewater application is considered to be extremely limited. These results come in agreement with that of El-Wakeel and Abd El-Naim (1986).

4.2 Hydrogen Ion Concentration (pH) The hydrogen ion concentration (pH) is an important factor controlling the

behavior of metals and many other chemical processes in soil and sediments. Mobility of heavy metals is pH dependent. Heavy metals are more mobile under acidic conditions, whereas they are sorbed onto mineral surfaces at higher pH (Dzombak and Morel, 1987). Increasing pH usually enhanced the sorption of


43

heavy metals as copper, zinc and cadmium (Cavallaro and McBride, 1978; Kuo and Baker, 1980; Soon, 1981). Acidic conditions will be more likely under land receiving wastewater effluents enriched in organic matter. Alkaline conditions will be more likely under silicate and carbonate parent material.

Results of the measured pH values are tabulated in Appendix (A),

a summary of descriptive statistics of pH values is shown in tables (4 through 8). A box-whisker graph showing the minimum, maximum, median, lower quartile (25%), and upper quartile (75%) of the pH values in the studied sediments is shown in figure (13). The spatial distribution of pH values is displayed in the contour map given in figure (14).

Assuming the present study, the measured pH values indicate that the Nile

floodplain and reclaimed lands are slightly alkaline to alkaline in nature with an average pH value fluctuated around 8. Generally, the pH values don not vary greatly throughout the stated landuses, with some exceptions. The pH values of wadi deposits are slightly higher reflecting the effect of the carbonate fraction. Similar results were obtained by Faragallah (1995), El-Desoky and Ghallab (1997), Abd El-Aziz (1998), Amira and Ibrahim (2000), Faragallah (2001), Ibrahim et al. (2001); Abd El-Aziz and Ghallab (2002).

Although most samples at El-Kola wastewater disposal site are slightly

alkaline to alkaline, some samples tend to be slightly acidic (pH<7). The mean value of pH for the whole site is still close to its value in the native wadi deposits reflecting the short period (about one year at beginning of sampling protocol) of wastewater disposal; the elevated carbonate content at this site is another factor.

On the other hand, most samples of El-Dair wastewater disposal site show

markedly lower pH values reaching down to 5.5 to be acidic in nature. Such depleted levels of pH are principally controlled by the application of organic matter-rich wastewater through the long-term practice (about 15 year). Decomposition of organic matter is the main source of hydrogen responsible for


44

increasing acidity. In addition, nitrification of ammonia associated with wastewater is another parameter (Schirado et al., 1986). These results comes in harmony with several others reported that pH decreases with the application of sewage effluent (Aboulroos et al., 1989; Chen and Barber, 1990; El-Shafei and El-Koumey, 1994; Abou Hussien and El-Koumey, 1997; Amira, 1997; Badawy and Helal, 1997). The slight higher pH value in some samples from subsoil layer of El-Dair farmlands follows the elevated content of carbonate.

4.3 Inorganic Carbonate Content (CaCOB3B) The carbonate (CaCOB3B) is a common component of sedimentary rocks but

it is less commonly present in weathered igneous and metamorphic rocks. It is also a common constituent of many soils. Water passing through soils and sediments can precipitate or dissolve calcite until equilibrium is achieved. This process has a strong influence on their carbonate content.

Calcium carbonate occurs in the form of calcite in some crystalline rocks

but is more generally deposited as a secondary mineral from water. In general, in arid and semi-arid regions the nearer to the topsoil are the calcium carbonate accumulations.

In calcareous soils, the carbonate occurs mostly in the silt fraction and

significantly affects the soil properties. Deb (1963) found that more than 75% of the calcium carbonate content is contained in the clay and silt fractions of soils near Aswan.

Chemically, carbonates can introduce soluble calcium and magnesium into

the soil complex, which are able to replace exchangeable constituents on the soil particles and colloids. Insoluble carbonates in a soil are usually reported as calcium carbonate.

El-Gibaly et al. (1972) studied the total carbonate content and its

distribution in the soil profiles around the River Nile. They found that the total


45

carbonate of the bulk samples is relatively less in soil close to the Nile course than those far away. Zeinel-Abedine et al. (1966) reported that the mainly two sources of carbonate in the Nile alluvium are: (1) the fine particles of carbonate mixed with the Nile suspended matter which contains about 2.8% of carbonateB

Bduring flooding periods Hafez (1962). (2) Transformation of Ca (HCOB3B)B2B in irrigation water and soil solution into carbonate. Most of these carbonates are accumulated in the topsoil layer (Ball, 1939; Mitwally, 1953).

Abd El-Aziz (1998) and El-Desoky et al. (2000) found that total carbonates

in soils of wadi El-Assiuti are not homogeneously distributed where wide range was reported (6.7-80.4%). Abd El-Maksoud et al. (2000) found that total calcium carbonate is generally high and significantly fluctuated (5.0-55.0%) in soils from wadi Qena.

Ibrahim et al. (2001) studied some soils of Sohag region and found that

total carbonate ranged between 7.28 and 56.4%, 1.07 and 7.68% and 0.00 and 7.05% for coarse-textured, medium-textured and fine-textured soils, respectively; similar results have been obtained by Negim (2003).

Regarding the present study, data of the carbonate content in the studied

sediments are given in Appendix (A). A summary of descriptive statistics for the carbonate content is shown in tables (4 through 8). A box-whisker graph showing the minimum, maximum, median, lower quartile (25%), and upper quartile (75%) of the carbonate values in the studied sediments is shown in figures (15 & 16). A contour map showing the distribution of carbonate (<63µm) is shown in figure (17).

The topsoil layer of the Nile floodplain exhibits a wide variation of

carbonate content, ranging from 0.31 to 10.3 % (mean= 3.8, median= 3.4%, sd.=2). On the other hand, the subsoil layer displays a less variable content ranging between 1.1 and 7.4% (mean=3.55, median=3.14%, sd.=2). The carbonate content shows insignificant difference through the topsoil and subsoil layers (p=0.628). These results are comparable with those reported in other


46

publications (e.g. Abdel-Aal, 1961; Abdel-Fattah, 1963; El-Toukhy, 1987). An important trend was observed in the topsoil layer, where the carbonate content increases away from the Nile stream toward the desert areas on both the eastern and western sides, reflecting the effect of the adjacent calcareous desert zone through the wind action. Although it is statistically insignificant (p=0.504), a slight higher content of carbonate is recorded along the eastern bank of the valley relative to the western one. This may be attributed to the flash floods, which are more common along the eastern higher relief limestone plateau; so the calcareous disintegration products are more dispersed east of the Nile.

On the other hand, the fine fraction (<63µm) of the floodplain sediments

(Fig. 16) shows a general slight increase in the carbonate content compared with the bulk samples. It ranges from 1.9 to 10.1% (mean=4.6, median=4.1%, sd.=2) and 1.3 to 20.8% (mean=5.2, median=4.4%, sd.=3) for the topsoil and subsoil layers, respectively. As in the bulk sample, the fine fraction has the same trend as carbonate increases towards the desert frings.

Regarding the topsoil layer of the reclaimed lands, the total carbonate content covers a wide range varying from 3.3 to 39.3% (mean=10.8, median=7.9%, sd.=8). The subsoil layer shows a significantly elevated content (p= 0.011) with a wide range fluctuating between 5.9 and 59.8% (mean=17.8, median=12.8%, sd.=13). On the other hand, the topsoil layer of the reclaimed lands possesses significantly higher carbonate content (p= <0.001) relative to that of the cultivated floodplains. This can be ascribed to the continuous mixing and reworking with the underneath calcareous subsoil layer as a result of the farming practice. Worthwhile to mention that, the reclaimed lands along the eastern side of the Nile are significantly enriched with the carbonate content compared with those of the western side (p=0.003 and 0.016 for the topsoil and subsoil layers, respectively). Generally, the variable carbonate content of the reclaimed lands is controlled principally by the relative abundance of the detrital sediments and the disintegration products from the carbonate terrains.


47

With respect to the carbonate content in the fine fraction (<63µm), the topsoil layer of the reclaimed lands shows a range fluctuating from 3.5 to 54.0% (mean=14.7, median= 8.4%, sd.=12). The subsoil layer displays values ranging between 5.9 and 72.5% (mean=34.1, median=32.7%, sd.=18). It is clear that the carbonate content in the bulk samples of the topsoil layer is markedly similar to that of the fine fraction. On the contrary, a great difference is reported in the subsoil layer where the carbonate content in the fine fraction is nearly three fold higher than the bulk samples. This reveals that the carbonate fraction of the subsoil layer is concentrated in the finely disintegrated calcareous product derived from the adjacent limestone terrains.

The total carbonate in the examined samples from wadi deposits ranges

from 6.3-58.4% (mean=22.7, median=21.0%, sd.=13). The result comes in harmony with that reported by Ibrahim et al. (2001) and Negim (2003) for desertic soils in Sohag Governorate. Wadi deposits along the eastern side of the Nile are significantly enriched with carbonate compared with the western one (p=0.011). The higher carbonate content east of the Nile may be attributed to the intense disintegration of the higher relief Eocene limestone plateau during the flooding periods. In addition, erosion of the nearby lacustrine Plio-Pleistocene calcareous rocks may play a significant role.

Regarding the fine fraction of the wadi deposits, the total carbonate content

falls in the range 18.3-56.8% (mean=32.5, median=30.4%, sd.=11). Hence, the carbonate content in the fine fraction is markedly higher than that of the bulk samples. This confirms the concentration of carbonate in the finely disaggregated calcareous materials derived from the nearby limestone rocks.

The calcium carbonate content in the bulk samples of the lands applied for wastewater disposal at El-Kola is widely variable being range from 1.0 to 59.5% (mean=15.9, median=8.1%, sd.=17). About 58% of samples have carbonate less than 10%. The total carbonate content at this site is relatively lower than that of the surrounding wadi deposits, although statistically less significant.


48

Accumulation of biosolids, as a result of raw wastewater disposal, is the main factor responsible for the carbonate dilution. The carbonate content in the fine fraction shows significantly higher content of carbonate than the bulk sample, it ranges between 8.2 and 60.0% (mean=27.8, median=23.9%, sd.=16).

The investigated samples (<2mm) from the wastewater ponds at

El-Dair include carbonate content ranging from 1.0 to 12.1% (mean=6.7, median=6.8%, sd.=3). These samples contain significantly lower levels of carbonate compared with the adjacent wadi deposits and even El-Kola disposal site (p=0.037 and 0.059, respectively). The markedly depleted level of the carbonate in the wastewater ponds at El-Dair is attributed to the dilution effect of organic matter accumulation through the long-term practice of raw wastewater disposal. Calcium carbonate in the fine fraction ranges between 6.5 and 47.3% (mean=25.2, median=27.3%, sd.=10). All samples have extremely higher content of carbonate in fine fraction than the bulk samples, confirming the stated assumption as that carbonates are concentrated in the finely disintegrated calcareous fraction.

The total carbonate content of the studied soil samples representing the area

occupied by the wastewater farmlands at El-Dair ranges between 0.6 and 9.9% (mean=5.6, median=6.6%, sd.=3) for the topsoil layer, whereas it fluctuates between 0.2 and 15.2% (mean=5.6, median=6.0%, sd.=4) in the subsoil layer. It is obvious that the topsoil and subsoil layers of the farmlands are very similar in their total carbonate content. The matter, which is statistically confirmed by the resulted insignificant variability (p=0.976). As the case for wastewater ponds, the content of calcium carbonate in the farmlands is significantly lower than that of the adjacent wadi deposits, documenting the mentioned interpretation.

The carbonate content in the fine fraction (<63µm) of El-Dair wastewater

farmlands ranges between 7.0 and 45.0% (mean=22.4, median=21.1%, sd.=13) and from 1.3 to 74.2% (mean=28.6, median=25.9%, sd.=13) for topsoil and subsoil samples, respectively. Although the two layers are seemingly similar in


49

their carbonate content of the fine fraction, the subsoil layer shows insignificant difference relative to the adjacent wadi deposits. The matter which is entirely different for the topsoil layer that is significantly (p=0.010) dissimilar with the wadi deposits, indicating that the major effect of wastewater practice is concentrated in the topsoil layer.

It is clear that the carbonate content in the sites applied for wastewater

disposal is negatively affected by such practice particularly in the surficial layer. This result comes in contradiction with some studies reported slight increase in the carbonate as the soil treated by wastewater (e.g. Bayoumi et al., 1993). The present results are attributed to the extremely elevated content of carbonate in the calcareous sediments of the sites. So, addition of biomass associated the wastewater will dilute rather increase the carbonate content.

4.4 Organic Matter Content (OM) Soil organic matter is defined as the organic fraction of the soil, excluding

the undecayed plant and animal residues; it commonly used as a synonymous of humus (Soil Science Society of America, 1987). The amount and type of organic matter in soil may vary considerably. Alloway et al. (1985) showed that organic matter is one of the key factors controlling the specific adsorption of trace metals by different soils.

Decau et al. (1963) pointed out that the organic matter content of the

irrigated soils in the arid regions is generally depleted due to their rapid decomposition. Hamdi (1958) stated that the organic matter content in most the cultivated soils in Egypt ranges between 0.2 and 2.0%. Fathi (1946), in a study at Giza area, found that the average organic matter content is 2.02% in the topsoil layer and decreases to 0.65% in the subsoil layer. Ibrahim and Omer (2004) reported that organic matter content in the Nile floodplain within Sohag area is fluctuated in the range 1-3%. Ibrahim et al. (2001) studied some soils in Sohag and found that organic matter content ranges between 0.1 and 2.6%; it is higher in clayey than sandy soils.


50

Labib (1992) stated that the continuous use of sewage water contributed to tremendous addition of organic matter to the soil. In their studies on El-Gabal El-Asfar farm near Cairo City, El-Shabasy et al. (1971) found that after 55 years from using sewage effluent, the soil organic matter content increased to a stable value of 6.2% in the topsoil and 2% in the subsoil layers. Bayoumi et al. (1993), postulated that soils irrigated with wastewater exhibit a remarkable increase in the organic matter content. These results are in agreement with those of Abd El-Naim et al. (1982), Shand et al. (1985), El-Wakeel and Abd El-Naim (1986) and Amira (1997). Many other studies indicated that, the application of sewage wastes to soil generally increases organic matter content (Gaynor and Halstead, 1976; Hinesly et al., 1979; Alaily, 1979; El-Nennah et al., 1982; El-Gendi et al., 1997).

With respect to the present study, results of the estimated organic matter

content in the examined sediments are given in Appendix (A). A summary of descriptive statistics for the organic matter content is listed in tables (4 through 8). A box-whisker graph showing the minimum, maximum, median, lower quartile (25%), and upper quartile (75%) of the organic matter values in the studied sediments is shown in figures (18 & 19). A contour map displaying the spatial distribution pattern of organic matter (63µm) throughout the study area is shown in figure (20).

The organic matter content in the samples from the topsoil layer of

the cultivated floodplain ranges from 0.82 to 2.5% (mean=1.68, median=1.66%, sd.=0.46). The organic matter content is considerably lower in the subsoil layer being range from 0.47 to 1.38% (mean=0.83, median=0.82%, sd.=0.20). The fine fraction (<63µm) exhibits relatively higher content of organic matter through both the topsoil and subsoil layers. In the topsoil layer, it varies from 1.11 to 3.2% (mean=2.1, median=2.1%, sd.=0.43), whereas it fluctuates from 0.65 to 2.18% (mean=1.35, median=1.34%, sd.=0.33) in the subsoil layer. The relative higher content of organic matter in the topsoil layer compared with the


51

deeper one is attributed to the continuous vegetation practice. No significant differences are reported in the organic matter content throughout the cultivated floodplain along the eastern and western sides of the valley.

Values of the bulk organic matter content in the topsoil layer of the

reclaimed lands range from 0.09 to 8.6% (mean=1.44, median =1.20%, sd.=1.44), while they vary from 0.03 to 1.24% (mean=0.24, median=0.12%, sd.=0.31) in the subsoil layer. Generally, the organic matter content of the topsoil layer is lower than that of the cultivated floodplain. Organic matter shows a significant enrichment (p<0.001) in the topsoil compared with the subsoil layer.

The fine fraction of these soils shows a relatively higher content of

organic matter than the bulk samples. It ranges between 0.15 and 22.6% (mean=2.62, median=1.91%, sd.=3.85) in topsoil layer and between 0.17 and 8.4% (mean=0.84, median=0.42%, sd.=1.45) for the subsoil layer. The abnormal elevated levels of organic matter in both bulk samples and fine fraction were reported in sites situated very close to the lands applied for wastewater disposal. The organic matter content in the subsoil layer, on the average, is closely akin to that of the adjacent wadi deposits.

The organic matter content in the bulk samples is extremely depleted

throughout the wadi deposits. The organic matter values range between 0.02 and 2.46% (mean=0.39, median=0.12%, sd.=0.62). An exceptional case was observed (No. 29), where it shows a comparatively higher content of organic matter. This site is located within the Issawia grave; so decay of the buried human bodies is the most probable source of the enhanced organic matter. The organic matter in the fine fraction is relatively higher than the bulk samples. It ranges between 0.13 and 3.42% (mean=0.77, median=0.50%, sd.=0.82).


52

Table (4): Summary of descriptive statistics for pH, total carbonate (CaCOB3B) and organic matter content in the cultivated floodplain (n= 70).

CaCOB3 B(%) OM (%) Depth (cm) pH

<63µm <2mm <63µm <2mm

00-20 8.1 4.6 3.8 2.10 1.68 Mean

20-40 8.1 5.2 3.6 1.35 0.83

00-20 8.1 4.1 3.4 2.10 1.66 Median

20-40 8.1 4.4 3.1 1.34 0.82

00-20 7.4 1.9 0.3 1.11 0.82 Minimum

20-40 7.6 1.3 1.1 0.65 0.47

00-20 9.0 10.1 10.3 3.20 2.50 Maximum

20-40 8.7 20.8 7.4 2.18 1.38

00-20 0.3 2.0 2.0 0.43 0.46 sd. 20-40 0.2 3.0 2.0 0.33 0.20

00-20 7.9 2.6 1.9 1.90 1.35 25% percentile

20-40 8.0 3.2 2.1 1.05 0.68

00-20 8.2 6.3 5.3 2.33 2.10 75% percentile

20-40 8.2 6.0 4.6 1.60 0.96

Table (5): Summary of descriptive statistics for pH, total carbonate (CaCOB3B) and organic matter content in the reclaimed lands (n= 65).

CaCOB3 B(%) OM (%) Depth (cm) pH

<63µm <2mm <63µm <2mm

00-20 8.1 14.7 10.8 2.62 1.44 Mean

20-40 8.3 34.1 17.8 0.84 0.24

00-20 8.2 8.4 7.9 1.91 1.20 Median

20-40 8.3 32.7 12.8 0.42 0.12

00-20 7.0 3.5 3.3 0.15 0.09 Minimum

20-40 7.3 5.9 5.9 0.17 0.03

00-20 8.6 54.0 39.3 22.6 8.60 Maximum

20-40 9.1 72.5 59.8 8.40 1.24

00-20 0.3 12.0 8.0 3.85 1.44 sd. 20-40 0.3 18.0 13.0 1.45 0.31

00-20 8.0 5.9 6.1 1.26 0.88 25% percentile

20-40 8.1 20.8 9.7 0.30 0.06

00-20 8.2 20.4 12.5 2.35 1.42 75% percentile

20-40 8.5 42.2 21.3 0.70 0.21


53

With respect to the lands applied for wastewater disposal at El-Kola, the organic matter content in the bulk samples varies widely covering the range between 0.01 and 13.7% (mean=2.45, median=0.20, sd.=4.1). About 62% of samples have organic matter less than 0.5%. The much higher levels of organic matter (3.99-13.7%) are recorded in the most contaminated sites. Such wide range of organic matter content reflects different grades of contamination with raw wastewater effluent. Sites with higher levels of organic matter are those characterized by elevated accumulation of biosolids at the wastewater dumps. However, sites displaying low organic matter content are those negligibly affected by wastewater; so, their organic matter content reflects its pristine level to be comparable with the surrounding wadi deposits. In fine fraction, the organic matter content is relatively higher than that of the bulk samples being range between 0.23 and 23.6% (mean=4.37, median=0.55%, sd.=6.42). The distribution pattern of organic matter in the fine fraction strictly follows that of the bulk samples under the same controlling factors. The obtained results agree with those reported in many studies (e.g. Gaynor and Halstead, 1967; Hinesly et al., 1979; Alaily, 1979; El-Nennah et al., 1982; Aboulroos et al., 1989; El-Gendi et al., 1997).

Table (6): Summary of descriptive statistics for pH, total carbonate (CaCOB3B) and organic matter content in the wadi deposits (n= 17).

CaCOB3 B(%) OM (%) pH <63µm <2mm <63µm <2mm

Mean 8.2 32.5 22.7 0.77 0.39

Median 8.2 30.4 21.0 0.50 0.12

Minimum 7.8 18.3 6.3 0.13 0.02

Maximum 8.7 56.8 58.4 3.42 2.46

Sd. 0.3 11.0 13.0 0.82 0.62

25% percentile 8.1 25.7 12.7 0.30 0.04

75% percentile 8.3 33.4 28.3 0.70 0.37


54

Table (7): Summary of descriptive statistics for pH, total carbonate (CaCOB3B) and organic matter content in lands applied for wastewater disposal at El-Kola (ponds and wetlands) (n=29).

CaCOB3 B(%) OM (%) pH <63µm <2mm <63µm <2mm

Mean 8.0 27.8 15.9 4.37 2.45

Median 8.1 23.9 8.1 0.55 0.20

Minimum 6.9 8.2 1.0 0.23 0.01

Maximum 8.5 60.0 59.5 23.60 13.73

sd. 0.5 16.0 17.0 6.42 4.10

25% percentile 7.8 13.4 3.1 0.38 0.10

75% percentile 8.3 39.9 21.4 6.48 2.80

The organic matter content in the bulk samples of the wastewater ponds at

El-Dair ranges between 0.10 and 53.7% (mean=10.3, median=4.10%, sd.=1.32), exhibiting the highest content throughout the study area. The abnormal accumulation of organic matter follows the long-term application of the raw wastewater in this site (~15 years). The threshold levels correspond to the central zone receiving more abundant wastewater-born biosolids. The content of organic matter in the fine fraction is considerably higher and ranging from 3.9 to 44.1% (mean=17.73, median=18.9%, sd.=10.58). Again, the behavior of organic matter in the fine fraction follows that of the bulk samples reflecting the same conditions.

Levels of organic matter content in the topsoil layer of the wastewater farmlands (bulk samples) at El-Dair range between 0.5 and 23.1% (mean=6.34, median=3.66%, sd.=6.54), whereas those of the subsoil layer vary between 0.03 and 1.02% (mean=0.42, median=0.32%, sd.=0.27). In the fine fraction, it ranges between 4.5 and 38.7% (mean=18.2, median=17.8%, sd.=13.7) and from 0.9 to 8.5% (mean=3.49, median=2.90%, sd.=2.3) for the topsoil and subsoil layers, respectively. Trend of organic matter in the fine fraction is also similar to that of the bulk samples. In general, the organic matter content in the wastewater


55

disposal site at El-Dair is markedly higher, on the average, than that reported at El-Kola reflecting the longer term of wastewater disposal.

Table (8): Summary of descriptive statistics of pH, total carbonate (CaCOB3B) and

organic matter (OM) content in lands applied for wastewater disposal at El-Dair (farmlands and ponds, n=30 and 15, respectively).

OM (%) CaCOB3 B(%) <2mm <63µm <2mm <63µm

pH Depth (cm)

6.34 18.18 5.6 22.4 6.9 0-20 0.42 3.49 5.6 28.6 7.4 20-40

Mean

3.66 17.80 6.6 21.1 7.1 0-20 0.32 2.90 6.0 25.9 7.4 20-40

Median

0.50 4.50 0.6 7.0 5.5 0-20 0.03 0.90 0.2 1.3 6.4 20-40

Minimum

23.10 38.70 9.9 45.0 7.9 0-20 1.02 8.50 15.2 74.2 8.1 20-40

Maximum

6.54 12.68 3.0 13.0 0.7 0-20 0.27 2.03 4.0 13.0 0.6 20-40

sd.

0.95 5.85 2.1 27.3 6.4 0-20 0.22 2.35 1.2 35.2 6.7 20-40

25% percentile

11.49 26.70 8.3 9.8 7.4 0-20 0.61 3.65 7.4 19.3 7.9 20-40

Farm

land

s

75% percentile

10.29 17.73 6.7 25.2 7.0 Mean 4.10 18.90 6.8 27.3 6.9 Median 0.10 3.90 1.0 6.5 5.5 Minimum 53.66 44.10 12.1 47.3 7.9 Maximum 1.32 10.58 2.6 9.8 0.6 sd. 8.52 8.30 4.9 18.6 6.6 25% percentile16.33 20.95 7.8 30.0 7.4

Surf

ace

laye

r

Was

tew

ater

pon

ds

75% percentile

4.5 Cation Exchange Capacity ( CEC ) Cation exchange capacity (CEC) refers to the quantity of negative charges

existing on the surfaces of the reactive particles as clay minerals and organic matter. These sites (negative charges) attract positively charged ions, or cations; hence the name “cation exchange capacity” came into existence. It indicates the ability of sediments and soil to adsorb cations and provides a reservoir for metal retention in soil and sediments. Consequently, the CEC controls the mobility and bioavailability of metals from sediments and soil (ADEME, 2001).


56

The primary factors determining CEC are the amount and type of clay minerals and organic matter content, as well as the acidity and textural characteristics of soil and sediments (Gedroiz, 1924; Kelley, 1964 and Iskender, 1967).

Results of the cation exchange capacity in the examined sediments are given in Appendix (B). A summary of descriptive statistics for the CEC values is given in table (9). A box-whisker graph showing the minimum, maximum, median, lower quartile (25%) and upper quartile (75%) of the CEC values in the studied sediments is shown in figure (21). The spatial distribution of CEC throughout the study area is displayed in the contour map shown in figure (22).

The estimated CEC values in the cultivated floodplain vary between 35 and

80 meq/100g (mean=55, median=54 meq/100g, sd.=10) and display no pronounced spatial trend throughout the study area.

The CEC values of the reclaimed lands are relatively less than those of the

cultivated floodplain; this may be due to their higher content of carbonate and lower content of clay fraction and organic matter. The measured values of CEC in the reclaimed lands vary between 11 and 58 meq/100g (mean=30, median=29 meq/100g, sd.=10).

The CEC values in the wadi deposits vary between 6 and 31 meq/100g

(mean=14, median=10 meq/100g, sd.=8). About 53% of samples have CEC values less than 10 meq/100g.

Table (9): Summary of descriptive statistics of the CEC (meq/100g) in the studied landuses.

Cation Exchange Capacity (meq/100g) Mean 55 30 14 31 18 22

Median 54 29 10 26 15 18

Minimum 35 11 6 8 5 5

Maximum 80 58 31 95 38 61

sd. 10 10 8 21 9 17

25% percentile 50 23 9 16 12 11

75% percentile

Cul

tivat

ed fl

oodp

lain

60

Rec

laim

ed la

nds

36

Wad

i dep

osits

19

Lan

ds a

pplie

d fo

r w

aste

wat

er a

t El-K

ola

34

Lan

ds a

pplie

d fo

r w

aste

wat

er a

t El-D

air

(farm

land

s)

21

Lan

ds a

pplie

d fo

r w

aste

wat

er a

t El-D

air

(was

tew

ater

pon

ds)

24


57

The CEC values of the lands applied for wastewater disposal at El-Kola vary between 8 and 95 (mean=31, median=26 meq/100g). Most of samples (about 75%) have CEC values less than 35 meq/100g, whereas the highest values exceeding 60 meq/100g were occasionally recorded. The values of the CEC of El-Kola site are higher than that of the adjacent wadi deposits.

The CEC values in the wastewater ponds at El-Dair vary between 5 and 61

meq/100g (mean=22, median=18 meq/100g, sd.=17), whereas the CEC values of the studied samples from the wastewater farmlands at El-Dair vary between 5 and 38 meq/100g (mean=18, median=15 meq/100g, sd.=9), where most samples (~87%) have CEC values less than 22 meq/100g.

In general, the CEC values are extremely fluctuated in the lands applied for

wastewater disposal. This reflects the variable contents of carbonate, clay minerals and organic matter in these sediments.


58

C

lay

(%)

0.5

1.0

5.0

10.0

50.0

1 2 3 4 5 6 7

Fig. (11): A box-whisker graph showing the minimum, maximum, median, lower quartile (25%) and upper quartile (75%) of the clay fraction content (%) in the studied sediments. See figure (9) for explanation.

%

26 3

2 00

N26

28

00 N

26 3

2 00

N26

28

00 N

31 32 00 E 31 36 00 E 31 40 00 E 31 44 00 E 31 48 00 E 31 52 00 E

Western limestone plateau

Eastern limestone plateau

Kilometers02.5 55

31 32 00 E 31 36 00 E 31 40 00 E 31 44 00 E 31 52 00 E31 48 00 E

10

25

40

Fig. (12): Contour map showing distribution of the clay content in the surficial sediments

throughout the study area.


59

pH

5

6

7

8

9

1 2 3 4 5 6 7

Fig. (13): A box-whisker graph showing the minimum, maximum, median, lower quartile (25%) and upper quartile (75%) of the pH values in the studied sediments (<2mm). See figure (9) for explanation.

7

8

9

26 3

2 00

N26

28

00 N

26 3

2 00

N26

28

00 N

31 32 00 E 31 36 00 E 31 40 00 E 31 44 00 E 31 48 00 E 31 52 00 E



Kilometers02.5 55

31 32 00 E 31 36 00 E 31 40 00 E 31 44 00 E 31 52 00 E31 48 00 E

Fig. (14): Contour map showing distribution of the pH values in the surficial sediments

throughout the study area.


60

C

aCO

3 (%

)

0

10

20

30

40

50

60

1 2 3 4 5 6 7

Fig. (15): A box-whisker graph showing the minimum, maximum, median, lower quartile (25%) and upper quartile (75%) of the carbonate content in the studied sediments (<2mm). See figure (9) for explanation.

CaC

O3 (

%)

0

10

20

30

40

50

60

70

80

1 2 3 4 5 6 7

Fig. (16): A box-whisker graph showing the minimum, maximum, median, lower quartile (25%) and upper quartile (75%) of the carbonate content (%) in the studied sediments (<63µm). See figure (9) for 1 through 7.


61

5

15

25

35

45

55

%

26 3

2 00

N26

28

00 N

26 3

2 00

N26

28

00 N

31 32 00 E 31 36 00 E 31 40 00 E 31 44 00 E 31 48 00 E 31 52 00 E



Kilometers02.5 55

31 32 00 E 31 36 00 E 31 40 00 E 31 44 00 E 31 52 00 E31 48 00 E

Fig. (17): Contour map showing distribution of the total carbonate in the surficial

sediments (<63 µm) throughout the study area.


62

O

rgan

ic m

atte

r (%

)

0.01

0.10

1.00

10.00

100.00

1 2 3 4 5 6 7

Fig. (18): A box-whisker graph showing the minimum, maximum, median, lower quartile (25%) and upper quartile (75%) of the organic matter content (%) in the studied sediments (<2mm). See figure (9) for explanation.

Org

anic

mat

ter (

%)

0.1

0.5

1.0

5.0

10.0

50.0

1 2 3 4 5 6 7

Fig. (19): A box-whisker graph showing the minimum, maximum, median, lower quartile (25%) and upper quartile (75%) of the organic matter content (%) in the studied sediments (<63µm). See figure (9) for explanation.


63

%

26 3

2 00

N26

28

00 N

26 3

2 00

N26

28

00 N

31 32 00 E 31 36 00 E 31 40 00 E 31 44 00 E 31 48 00 E 31 52 00 E



Kilometers02.5 55

31 32 00 E 31 36 00 E 31 40 00 E 31 44 00 E 31 52 00 E31 48 00 E

2

6

10

14

18

22

26

Fig. (20): Contour map showing distribution of the organic matter content in the surficial

sediments (<63 µm) throughout the study area.


64

C

EC (m

eq/1

00g)

4

6

8

10

20

40

60

80

100

1 2 3 4 5

1- Cultivated floodplain 2- Reclaimed lands 3- Wadi deposits4- Wastewater disposal site at El-Kola5- Wastewater disposal site at El-Dair

MaxMin75%25%Median


(25%) and upper quartile (75%) of the cation exchange capacity (meq/100g) in the studied sediments (<2mm).

20

40

60

80

26 3

2 00

N26

28

00 N

26 3

2 00

N26

28

00 N

31 32 00 E 31 36 00 E 31 40 00 E 31 44 00 E 31 48 00 E 31 52 00 E



Kilometers02.5 55

31 32 00 E 31 36 00 E 31 40 00 E 31 44 00 E 31 52 00 E31 48 00 E

meq/100g

Fig. (22): Contour map showing distribution of the cation exchange capacity (meq/100g) in

the surficial sediments (<2mm) throughout the study area.

HEAVY METALS

CHAPTER 5 HEAVY METALS

HEAVY METALS

65

CHAPTER 5 HEAVY METALS

5.1 Total Metal Content 5.1.1 Introduction

The geochemistry of modern sediments can provide useful indicators of their origin and record effects of anthropogenic (human) activities. Sediments are important carriers for trace metals in the terrestrial environment and they can reflect the current quality of the system as well as the historical development of certain chemical parameters. Chemical analysis of sediments is considered to be an important tool within the framework of environmental forensic investigations (Meiggs, 1980; Forstner and Wittman, 1981; Alderton, 1985). Sediments have been used as an indicator of changes in environmental concentrations of pollutants in many parts of the world (e.g., Hakanson, 1977; Kemp et al., 1978; Galloway and Likens, 1979).

The finer particles of sediments are the most important in the

environmental geochemistry being include the significantly reactive constituents as the clay minerals, organic matter and amorphous oxides and hydroxides (Salomons and Forstner, 1984; Reitner and Kralic, 1997). These constituents play an effective role in the metal mobilization and immobilization among their ability for metal sorption and desorption under the surficial conditions.

In addition, the fine particles have large relative surface areas available for

metal adsorption and, thus, metals tend to accumulate in the finer fraction (Jarvis and Higgs, 1987; Berrow and Mitchell, 1991; Queralt and Plana, 1992; Kabata-Pendias, 1993; Taher and Attia, 1999; Omer, 2003b). Therefore, the finer silt and clay fraction (<63 µm) comprises the major carriers for metals from both natural and anthropogenic sources and has the greatest potential for heavy metals accumulation. This fraction is accordingly the most appropriate and recommended for environmental and metal pollution assessment (Forstner and

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Salomons, 1980; Forstner and Wittmann, 1981; Ellawy et al., 1982; Millward et al., 1999). Hence, the finer the sediments are the more sensitive to metal accumulation and convenient for pollution monitoring. Therefore, the fine fraction (<63 µm) was considered in the present study to quantify the distribution pattern of heavy metals in the investigated sediments and discuss their association and sources.

In order to monitor the various anthropogenic impacts on the spatial

distribution pattern of heavy metals, geochemical maps were constructed for the study area. Such geochemical maps visually display the spatial distribution of metals in the investigated sites and the potentially hazard spots can be easily identified (Goodchild et al., 1993). In the present study, the spatial variation of the estimated heavy metals (Fe, Mn, Co, Ni, Cr, Pb, Zn, Cu and Cd) is displayed on geochemical contour maps.

5.1.2 Metal distribution and variability Data of the estimated heavy metals (Fe, Mn, Co, Ni, Cr, Pb, Zn, Cu and

Cd) through the studied sediments are given in Appendix (C). A summary of descriptive statistics for the heavy metals content throughout the study area is listed in tables (10 through 14). The calculated correlation coefficient between the heavy metals and the various soil properties is shown in Appendix (D). Distribution and variability of these metals throughout the different landuses in the study area will be discussed in the following sections.

5.1.2.1 Iron (Fe)

Iron in soils is mostly presented either as a component of various minerals (e.g. iron oxides, pyroxenes, amphiboles, biotite and olivine), or in the form of amorphous oxides and hydroxides. Lindsay (1972) reported that iron in soils exists in the primary as well as secondary minerals.

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Several investigators studied the total iron content of Egyptian soils. Among them, Tayel et al. (1966) found that the iron content ranges from 1-7% depending upon the textural characteristics of soil. Hollah (1977) found that the total iron ranged from 1.09-8.3% with a median of 5.95%; the highest content recorded in the alluvial soils while the lowest characterizes the sandy and calcareous soils. However, a wide range of total iron content was found by Abdel-Kader and Abu Ghalwa (1973) and Metwally and Abdellah (1978), where the total iron content varied from 1.7 to 12.9% and 2.8-13.8%, respectively. Also, they found that there was significant positive correlation between clay and total iron and a significant negative correlation between total carbonate and iron content.

Total iron in the soils of Sohag Governorate falls in range 1.16 to 5.83%

(Abd El-Razek et al., 1984a). They also found that the soil content of total iron was highly correlated with soil texture. Similar results were obtained by El-Sebaay (1995) and Faiyad et al. (1997).

The minimum, maximum, median, lower quartile (25%) and upper quartile

(75%) of iron content among the landuses concerned in the present study are shown in the box-whisker graph given in figure (23). A geochemical contour map displaying the spatial distribution of iron throughout the study area is given in figure (24).

Regarding the cultivated floodplain (Table 10), the iron content ranges

from 3.7 to 8.2% (mean=6.7, median=6.8%, sd.=0.94) in the topsoil layer, whereas it varies between 5.0 and 9.3% (mean= 7.4, median=7.5, sd.=0.78) in the subsoil layer. Although the low variability of iron in both the topsoil layer and the subsurface layer (sd.=0.94 and 0.78, respectively), a significant difference was reported among the two layers (p=0.003). Slight higher content of iron was found in the subsoil layer following the relative higher content of the clay fraction; dilution of organic matter in the topsoil layer may be another factor. The lowest iron concentration in the subsoil layer (5.0%) was reported at site No.88; this

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sample contains abundant carbonate fraction (20.8%) that diluted the iron content. Although the iron content of the cultivated floodplain is significantly higher than that of the average shale (4.7%, Turekian and Wedepohl, 1961), it is strongly similar to that of the PAAS (6.3%, Taylor and McLennan, 1985). The relative enrichment of iron in the sediments of the Nile floodplain is controlled by the source rock composition, where they are derived principally from the Ethiopian basaltic plateau (Omer, 1996 and references therein). In addition, the relative higher content of fine fraction in these sediments is another factor where iron is bound mainly in the fine fraction in most sediments (see Tayel et al., 1966; Karim and Hussain, 1970; Nair and Cottenine, 1971).

The estimated concentrations of iron in the reclaimed lands range from 1.8

to 12.3% (mean=6.0, median=6.2%, sd.=1.8) in the topsoil layer, whereas it varies between 1.3 and 7.8% (mean=4.2, median=4.0%, sd.=1.6) in the subsoil layer (Table 11). Generally, the iron content of the topsoil layer is significantly higher than that of the subsoil one (p=0.001); this matter is controlled by the different source material of the two layers. The total iron of the topsoil layer is very close to that of the cultivated floodplain, whereas its level in the subsoil layer is very akin to that of the adjacent wadi deposits. The elevated levels of iron in the topsoil layer follow the clay fraction content, whereas its lower concentration in the subsoil layer is governed by the higher content of carbonate fraction.

Levels of the total iron in the wadi deposits of the study area (Table 12)

range from 2.5 to 5.9% (mean=4.1, median=4.1%, sd.=0.99). Wadi deposits exhibit significantly lower iron content than the cultivated floodplain (p<0.001); the matter which is controlled by the carbonate dilution, where iron is negatively correlated with the carbonate content. The present result comes in harmony with that of El-Gala and Hendawy (1972), where they reported that the lowest content of iron was recorded in the desertic calcareous soils whereas the highest content was found in the alluvial soils.

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Regarding the distribution pattern of iron in the lands applied for wastewater disposal at El-Kola (ponds and wetlands) (Table 13), it ranges from 1.9 to 7.0% with a mean value of 4.6% (median=4.8%, sd.=1.3). Such level of iron, on the average, is considerably lower than that of the cultivated floodplain whereas it is very close to that of the nearby wadi deposits (p=0.235). Iron is significantly correlated with chromium and nickel (r=0.74 and 0.59, respectively), while it shows significant negative correlation with cadmium and carbonate (r=-0.52 and –0.62, respectively). Less significant positive correlation was reported with the other metals. This behavior of iron emphasizes its natural distribution manner as controlled by the lithological characteristics of the non-calcareous fraction particularly the argillaceous fraction derived from the Pliocene clays. The carbonate fraction acts as a dilution factor affecting the iron content reversely. Therefore, it is deemed that the iron level is insignificantly influenced by the wastewater disposal practice.

With respect to the total content of iron in the lands applied for wastewater

disposal at El-Dair (Table 14), it varies between 2.3 and 4.7% (mean=3.5%, median=3.6%, sd.=0.78) in the topsoil layer of the wastewater farmlands, whereas it ranges from 1.2 to 6.7% (mean=4.0, median=3.9%, sd.=1.5) in the subsoil layer. The total iron content exhibits insignificant difference between the topsoil and subsoil layers (p=0.193). The estimated iron content in the wastewater farmlands, on the average, is markedly lower than that reported for the cultivated floodplain, while it is very closely akin to that of the wadi deposits. In the topsoil layer, iron is positively correlated with cobalt, chromium and nickel (r=0.47, 0.42 and 0.39, respectively), but a negative correlation (r=-0.44) was found with organic matter. On the other side, iron is positively correlated with manganese, chromium, nickel and cobalt (r=0.60, 0.63, 0.48 and 0.41, respectively) and negatively correlated with cadmium and carbonate (r=-0.68 and -0.72, respectively) in the subsoil layer. The mentioned results confirm the natural geogenic source of iron and reflect the dilution effect of organic matter in the topsoil layer and the carbonate in the subsurface one.

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The total iron concentration measured in the surficial sediments of the wastewater ponds at El-Dair (Table 14) displays a wide range varying from 1.4 to 13.9% (mean=4.4, median=3.4%) as indicated from the higher value of standard deviation (sd.=3.3). Iron is positively correlated with cobalt, nickel, chromium and clay content (r=0.83, 0.78, 0.45 and 0.52, respectively), while it is negatively correlated with the carbonate and organic matter content (r=-0.44 and -0.23, respectively) (Appendix D-4). These data may reveal the lithogenic parentage of iron and reflect the dilution influence of the carbonate and organic matter. The exceptional abnormally elevated level of iron recorded in some samples might be attributed to the corrosion of the transporting pipes by the chemically reactive wastewater.

5.1.2.2 Manganese (Mn)

Manganese in soils originates primarily from the decomposition of ferromagnesian minerals. Soils derive all their manganese content from the parent materials, and the concentrations found in mineral soils reflect the composition of these parent materials.

Regarding the total content of manganese in different soils, Singh (1969)

found that the total manganese content of some Indian soils varied from 150 to 612 ppm. Moreover, Srivastva et al. (1970) postulated that total manganese content in alluvial and sedimentary soils of India ranged from 400-900 and 620-2040 ppm, respectively. Malewar et al. (1978) demonstrated that total manganese of some Indian soils ranged from 1042 to 1814 ppm. Berrow and Reaves (1984) reported an average of soil manganese as 450 ppm. They considered this value to be as background content in uncontaminated soils.

In the Egyptian soils, Orabi (1968) found that the total manganese content

ranged from 750 to 1938 ppm, with an average of 1428 ppm. El-Sherif et al. (1970a) demonstrated that manganese content was generally higher in the alluvial soils. El-Damaty et al. (1971) mentioned that alluvial soils were rich in total manganese because of the annual sedimentation transported by the Nile water.

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Similar results were obtained by Ghanem et al. (1971) who found that total manganese ranged from 116 to 1300 ppm, the values being higher in the alluvial than those of the calcareous and sandy soils. In a study on soils of Middle and Upper Egypt, Kishk et al. (1980) found that total manganese ranged between 111 to 1187 ppm, the highest values were found in the fine textured alluvial soils and the lowest values in the sandy and calcareous ones. Rashad et al. (1995) found that the content of total manganese in the normal alluvial soils of Delta ranged between 720 and 1080 ppm, with an average of 926 ppm. El-Sherif et al. (1970 a, b) established a positive correlation between the total manganese and clay content and negative correlation with carbonate.


(75%) of manganese content through the studied sediments, in the present study, are given in the box-whisker graph shown in figure (25). A geochemical contour map showing the spatial distribution pattern of manganese through the study area is displayed in figure (26).

The total content of manganese in the topsoil layer of the cultivated

floodplain (Table 10) falls in the range 604-2193 ppm (mean=1312, median=1305 ppm, sd.=246). On the other hand, the total manganese concentration of the subsoil layer varies from 1055 to 1885 ppm (mean=1378, median=1365 ppm, sd.=150). Although insignificant statistical difference was reported in the manganese content through the topsoil and subsoil layers (p=0.182), a general higher level was found in the subsoil layer. Ghanem et al. (1971) showed that the manganese level in the alluvial soils is fluctuated in the range 533-1300 ppm. Also, Metwally et al. (1971) reported that the manganese values in the alluvial soils fall in the range 1125-1375 ppm. So, the manganese content of the cultivated floodplain estimated in the present study is strictly comparable to the other studies. On the other hand, the total manganese content of the cultivated floodplain is significantly higher than that reported for the average shale (850 ppm) by Turekian and Wedepohl, (1961). Such relative higher content of manganese in the floodplain is attributed to its

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elevated level in the parent source rocks particularly the basaltic rocks of the Ethiopian plateau, where manganese is mainly present substituting iron in the structure of ferromagnesian silicate minerals (Gilkes and McKenzie, 1988).

In the topsoil layer of the cultivated floodplain, manganese shows

significant positive correlation with cobalt, iron and nickel (r=0.62, 0.52 and 0.34, respectively), whereas it is negatively correlated with zinc, copper and lead (r=-0.43, -0.43 and -0.35, respectively). This behavior may reflect the natural association of manganese with the former metals and point to the occasional anthropogenic impact on the later ones. On the other hand, the interrelation between manganese and other metals in the subsoil layer is markedly changed (Appendix D-1). It has a positive correlation with nickel, cobalt, copper and iron (r=0.53, 0.47, 0.35 and 0.25, respectively), while it shows a very weak correlation with the other metals particularly zinc and lead. This pattern reflects the natural composition of sediments and verifies the extremely limited anthropogenic impact in the subsoil layer.

However, the estimated manganese values in the topsoil layer of the

reclaimed lands (Table 11) range from 694 to 3505 ppm (mean=1293, median=1299 ppm, sd.=413). On the other hand, the subsoil layer possesses manganese content varying from 275 to 1355 ppm (mean=968, median=1035 ppm, sd.=277). The topsoil layer exhibits significantly higher manganese level relative to the subsoil layer (p<0.001). Although no significant difference was found in its content through the topsoil layers of the reclaimed lands and the cultivated floodplain (p=0.810), manganese shows a diverse behavior among the two layers.

In the topsoil layer of the reclaimed lands, manganese shows a significant

positive correlation with the organic matter and lead (r=0.71 and 0.78, respectively) and to a less extent zinc and copper (r=0.23 and 0.14, respectively). The tight interrelation between manganese and organic matter in the reclaimed lands was also documented in other studies (e.g. El-Sherief et al., 1970; El-Damaty et al., 1971; Rashad, 1986). On the other side, manganese has a

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significant negative correlation with the carbonate (r=-0.39) whereas it displays a very weak relation with iron, cobalt and nickel (Appendix D-2). This behavior reveals that manganese is substantially influenced by the reclamation practice, particularly the addition of agricultural amendments.

In the subsoil of the reclaimed lands, manganese possesses a significant

positive correlation with iron, cobalt and nickel (r=0.83, 0.49 and 0.43, respectively) while it is negatively correlated with cadmium and carbonate (r=-0.76 and –0.80, respectively). Manganese shows a very weak interrelation with lead, zinc and copper. Such behavior of manganese reflects its geogenic generation in the subsoil layer and that it is incorporated principally in the argillaceous fraction transported from the Pliocene clays. So, the carbonate fraction has a dilution effect on the distribution of manganese.

With respect to the investigated wadi deposits (Table 12), the total

manganese content is oscillating in the range 449-1181 ppm (mean=895, median=923 ppm, sd.=209). No significant difference was reported in the manganese concentration through the eastern and western sides of the Nile Valley (p=0.741). The total manganese level in the wadi deposits, on the average, is considerably lower than that reported in the cultivated floodplain. This manner comes in harmony with other studies postulated that manganese is markedly higher in the alluvial than the calcareous and sandy soils (e.g. Ghanem et al., 1971). Manganese has a significant negative correlation with carbonate (r=-0.412) suggesting that the major part of manganese is included in the fine argillaceous fraction derived from the nearby Pliocene clay rather than the calcareous fraction. The strong positive correlation (Appendix D-3) of manganese with iron and cobalt (r=0.83 and 0.69, respectively) may confirm this assumption.

Concerning the total manganese concentration in the lands applied for

wastewater disposal at El-Kola (Table 13), it varies from 258 to 5418 ppm (mean=1058, median=850 ppm, sd.=906). The average content of manganese in

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these sediments is relatively lower than its level in sediments of the Nile floodplain, but there is a considerable resemblance with its content in the wadi deposits. The high value of standard deviation reflects the wide range and extreme variability of manganese in these sediments. In addition, manganese shows no significant correlation with any of the other variables suggesting its independent and complicated behavior in the considered sediments.

The total manganese content estimated in the topsoil layer of the

wastewater farmlands at El-Dair (Table 14) fluctuates between 583 and 4213 ppm (mean=1121, median=884 ppm, sd.=873). In the subsoil layer, it varies from 482 to 1421 ppm (mean=1065, median=1074 ppm, sd.=274). Although its wide range in soils of these farmlands, the total manganese content, on the average, is relatively lower than that reported for the cultivated floodplain but it is very close to that of the wadi deposits.

Regarding the inter-variable relationship in the topsoil layer of the

wastewater farmlands (Appendix D-5), the total manganese is positively correlated with zinc, copper, lead and organic matter (r=0.68, 0.49, 0.47 and 0.29, respectively), whereas it shows negative correlation with carbonate (r=-0.34). On the other hand, manganese is positively correlated with iron, cobalt, nickel and chromium (r=0.60, 0.67, 0.39 and 0.33, respectively) while it is negatively correlated with carbonate and cadmium (r=-0.49 and –0.33, respectively) in the subsoil layer. The stated behavior of manganese in soil of the wastewater farmlands reveals that it is significantly affected by the farming practice in the topsoil layer where a considerable part is incorporated in the organic matter fraction. Contrarily, the major part of manganese in the subsoil layer is included in the lithogenic fraction particularly the argillaceous portion. Such conclusion can be confirmed by the dilution effect of the carbonate fraction in both of the two layers.

The total manganese level estimated in sediments of the wastewater ponds

at El-Dair (Table 14) ranges between 557 and 2434 ppm (mean=1171,

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median=855 ppm, sd.=615). It is clear that manganese covers a wide range of concentration as indicated from the higher value of standard deviation. The average manganese content in these sediments is comparatively lower than that of the cultivated floodplain whereas it is extremely similar to that of the wadi deposits. With respect to its relation with the other variables (Appendix D-4), manganese exhibits positive correlation with the clay fraction and organic matter content (r=0.42 and 0.36, respectively), while it is negatively correlated with the carbonate content, nickel, copper and cadmium (r=-0.35, -0.46, -0.55 and -0.39, respectively). Therefore, it can be concluded that although the major part of manganese is associated with the lithogenic clay fraction, a significant portion is incorporated in the organic matter.

5.1.2.3 Cobalt (Co)

Cobalt is most abundant in the relatively unstable ferromagnesian minerals such as olivine, pyroxene, amphibole, and biotite, which are concentrated in basic and ultrabasic igneous rocks (Mitchell, 1964; Aubert and Pinta, 1977). The cobalt content of sedimentary rocks reflects the composition of the material from which they were originally derived. The average total cobalt content of soils is usually in the range of 1-40 ppm, but values up to 800-1000 ppm have been reported from areas where cobalt minerals are present (Hawkes, 1952; Swain, 1955). The only significant sources of cobalt in soils are: 1) the parent materials from which the soils are derived, and 2) application of cobalt salts or Co-treated phosphate fertilizers (Smith, 1990).

With respect to the present study, the box-whisker graph given in figure

(27) shows the minimum, maximum, median, lower quartile (25%) and upper quartile (75%) of cobalt content through the investigated landuses. The spatial distribution pattern of cobalt content throughout the study area is shown in the geochemical contour map displayed in figure (28).

The measured content of the total cobalt in the topsoil layer of the

cultivated floodplain (Table 10) ranges between 15 and 43 ppm

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(mean=35, median=36 ppm, sd.=5). In the subsoil layer, it varies from 31 to 44 ppm (mean=38, median=38 ppm, sd.=3). In general, cobalt concentration is significantly higher in the subsoil layer compared with the topsoil one (p<0.015). Also, cobalt displays a wide range of concentrations in the topsoil layer compared with the subsoil layer. This reveals a less homogeneous distribution of cobalt in the topsoil layer, reflecting a considerable contribution in its distribution throughout this layer. The cobalt level in sediments of the floodplain is considerably higher than that reported for the average shale (19 ppm) by Turekian and Wedepohl (1961). The only significant source of cobalt in sediments is the parent material from which they are derived. Although the total cobalt content of soils vary widely, an average content in the range 10-15 ppm was reported (Aubert and Pinta, 1977). It is obvious that the cobalt content estimated in the cultivated floodplain is considerably higher than that of the average soil. Such elevated level of cobalt is attributed to the nature of the parent material in the hinterlands especially the basaltic rocks in the Ethiopian plateau; cobalt is most abundant in the ferromagnesian minerals substituting iron and magnesium which are concentrated in basic rocks (Mitchell, 1964; Aubert and Pinta, 1977).

The data presented in Appendix (D-1) shows that the total cobalt content is

positively correlated with iron, manganese and nickel (r=0.61, 0.62 and 0.52, respectively), while it is negatively correlated with copper, zinc and lead (r=-0.64, -0.61 and -0.42, respectively) in the topsoil layer of the cultivated floodplain. In the subsoil layer, cobalt is also positively correlated with iron, manganese and nickel (r=0.38, 0.47 and 0.60, respectively), whereas it is negatively correlated with lead (r=-0.29) and it is insignificantly correlated with the other metals. The stated behavior of cobalt may reflect its natural occurrence as controlled by nature of the parent rocks although some contribution of its distribution pattern may occur particularly in the topsoil layer.

With respect to the distribution pattern of total cobalt in the reclaimed lands

(Table 11), it ranges from 17 to 40 ppm (mean=33, median=35 ppm, sd.=6) in the

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topsoil layer, while it varies between 21 and 38 ppm (mean=28, median=27 ppm, sd.=5) in the subsoil layer. It is evident that the total content of cobalt in the topsoil layer is significantly higher than that of the subsoil layer (p<0.001), whereas it is very close to that of the cultivated floodplain. On the other hand, cobalt concentration in the subsoil layer of the reclaimed lands is very similar to its level in the nearby wadi deposits (p=0.308).

In the topsoil of the reclaimed lands, cobalt is positively correlated

(Appendix D-2) with iron, copper, nickel and clay content (r=0.73, 0.55, 0.70 and 0.34, respectively), while it is negatively correlated with lead, cadmium, zinc, organic matter and carbonate content (r=-0.57, -0.51, -0.37, -.059 and -0.75, respectively). This pattern indicates that cobalt of the topsoil layer is principally naturally included in the clay-rich fraction of these sediments. On the other side, cobalt is positively correlated with iron, manganese, nickel and the clay content (r=0.68, 0.49, 0.82 and 0.69, respectively), whereas it is negatively correlated with lead, cadmium and the carbonate content (r=-0.57, -0.45 and -0.45, respectively) in the subsoil layer. The mentioned behavior of cobalt in the subsoil layer of the reclaimed lands reflects its incorporation primarily in the argillaceous fraction derived from the Pliocene clays and, therefore, it is considerably diluted by the carbonate fraction.

Regarding the distribution manner of the total cobalt in the investigated

wadi deposits (Table 12), it fluctuates in the range 21-35 ppm (mean=29, median=30 ppm, sd.=5). The data presented in Appendix (D-3) shows that cobalt is positively correlated with iron, manganese, copper and nickel (r=0.78, 0.69, 0.45 and 0.51, respectively). A positive correlation was also reported with lead and zinc (r=0.57 and 0.43, respectively). Contrarily, cobalt displays a negative correlation with the organic matter and carbonate content (r=-0.50 and -0.26, respectively). Consequently, it can be concluded that cobalt of the wadi deposits is contained mainly in the argillaceous fraction derived from the Pliocene clays and it is reversely proportional with the carbonate content.

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Regarding the distribution manner of the total cobalt in the lands applied for wastewater disposal at El-Kola (ponds and wetlands) (Table 13), it fluctuates in the range 21-54 ppm (mean=33, median=31 ppm, sd.=8). Such level of cobalt, on the average, is significantly lower than that of the cultivated floodplain (p=0.012), whereas it is considerably close to that of the nearby wadi deposits (p=0.064). Cobalt is positively correlated with iron and chromium (r=0.32 and 0.38, respectively), insignificant positive correlation was observed with clay and manganese (r=0.15 and 0.28, respectively). On the other hand, cobalt exhibits a significant negative correlation (Appendix D-4) with organic matter, carbonate content, lead, zinc and copper (r=-0.57, -0.37, -0.61, -0.52 and -0.37, respectively), whereas it has insignificant correlation with cadmium (r=-0.23). Consequently, it can be concluded that cobalt of this site is contained mainly in the argillaceous fraction derived from the Pliocene clays. The carbonate and organic matter fractions act as a dilution factor affecting the cobalt content reversely. Therefore, it is deemed that the cobalt level is not influenced by the wastewater disposal practice in this site.

With respect to the lands applied for wastewater disposal (farmlands) at

El-Dair (Table 14), the total cobalt content varies between 13 and 27 ppm (mean=22, median=20 ppm, sd.=5), and from 20 to 31 ppm (mean=26, median=27 ppm, sd.=3) in the topsoil and subsoil layers, respectively. The total cobalt content of the topsoil layer is significantly lower than that of the subsoil layer and wadi deposits (p=0.004 and 0.001 respectively), the matter which is controlled principally by the dilution effect of organic matter (r=-0.89). In the topsoil, statistical analysis (Appendix D-5) proved a significant positive correlation between total cobalt and both iron and chromium (r=0.47 and 0.48, respectively), but a negative correlation was found with lead, zinc and copper (r=-0.58, -0.50 and –0.49, respectively). On the other side, cobalt is positively correlated with iron, manganese and nickel (r=0.41, 0.76 and 0.48, respectively) and negatively correlated with carbonate and organic matter (r=-0.35 and –0.48, respectively) in the subsoil layer. The mentioned results confirm the natural

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geogenic source of cobalt and reflect the dilution effect of organic matter in the topsoil layer and carbonate in the subsurface one.

The cobalt concentration in the surficial sediments of the wastewater ponds

at El-Dair (Table 14) ranges from 15 to 39 ppm with a mean value of 24 ppm (median=22 ppm, sd.=8). No significant variability was recorded in the cobalt concentration throughout the lands applied for wastewater disposal at El-Dair (ponds and wastewater farmlands). However, cobalt concentration is significantly low compared with that reported in the wadi deposits and lands applied for wastewater disposal at El-Kola (p=0.030 and 0.007, respectively). Cobalt has a significant negative correlation (Appendix D-4) with carbonate (r=-0.57), less significant with organic matter (r=-0.16) suggesting their dilution effect. The strong positive correlation of cobalt with clay, iron, nickel and chromium (r=0.62, 0.83, 0.81 and 0.50 respectively) suggests that the main part of cobalt is included in the fine argillaceous fraction rather than the calcareous fraction.

5.1.2.4 Nickel (Ni)

The occurrence of nickel varies between different rock types. Rocks rich in ferromagnesian and sulfide minerals have elevated levels of nickel (e.g. pyroxene, olivine, biotite and chlorite) where nickel substitutes for iron and magnesium.

The content of nickel in a soil depends very much on the nature of the

parent materials. Mitchell (1954) divided soils into two groups: 1) those derived from sandstone, limestone or acid igneous rocks, containing less than 50 ppm; and 2) those derived from argillaceous sediments or basic igneous rocks, containing from 5 to more than 500 ppm nickel. Thornton and Webb (1980) stated the normal levels of nickel in soils of 2-100 ppm. The average concentration of nickel in uncontaminated soils is less than about 40 ppm (Vinogradov, 1959; Adriano, 1986). Ure and Berrow (1982) in a more recent survey quoted an average of 93 ppm. Also, Bowen (1979) reported a median value for nickel in soils of 50 ppm. For the Egyptian soils, Rashad et al. (1995)

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gave a range of 21-44 ppm as the total nickel content of alluvial soils in the Nile Delta with average of 32 ppm.

In the present study, the minimum, maximum, median, lower quartile

(25%) and upper quartile (75%) of nickel content through the various landuses are displayed in the box-whisker graph given in figure (29). A geochemical contour map showing the spatial distribution pattern of nickel through the study area is displayed in figure (30).

The total nickel content estimated in the topsoil layer of the cultivated

floodplain (Table 10) varies from 51 to 119 ppm (mean=68, median=67 ppm, sd.=11). In the subsoil layer, nickel values range between 54 and 84 ppm (mean=69, median=70 ppm, sd.=6). No significant difference was found in the nickel level through the topsoil and subsoil layers (p=0.490). The average concentration of nickel in the cultivated floodplain is strictly comparable with that reported for the average shale (68 ppm) by Turekian and Wedepohl (1961). On the other hand, the present nickel level is relatively higher than the average concentration accounted for the world soils by Berrow and Reaves (1986) and Alloway (1990) to be 24 and 40 ppm, respectively.

Generally, the nickel content in soils depends very much on the nature of

the parent material. Hence, the relatively elevated nickel level in the sediments of the Nile floodplain is governed by nature of the parent material in the hinterlands particularly the basaltic rocks of the Ethiopian plateau, where nickel substitutes for iron and magnesium in the ferromagnesian minerals.

In the topsoil layer of the cultivated floodplain, nickel is positively

correlated with cobalt, iron and manganese (r=0.52, 0.44 and 0.34, respectively), whereas it shows very weak relation with lead, copper, cadmium and zinc (Appendix D1); such behavior reflects the natural association of nickel with the former metals as controlled by the lithological characteristics of the sediments. The same interrelation between nickel and other metals was reported in the

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subsoil layer, except for copper where a positive correlation (r=0.42) was observed. This matter follows the geogenic natural behavior of copper in the subsoil layer of the cultivated floodplain, as stated above.

The measured nickel content in the topsoil layer of the reclaimed lands

(Table 11) ranges from 33 to 78 ppm (mean=61, median=64 ppm, sd.=10), while its level in the subsoil layer varies between 28 and 70 ppm (mean=43, median=40 ppm, sd.=11). Statistically, it is pronounced that nickel is significantly higher in the topsoil layer (p<0.001) compared with the subsoil one. The elevated nickel concentration in the topsoil layer follows the lithological characteristics as the case for the cultivated floodplain. So, the positive correlation of nickel with iron (r=0.52), cobalt (r=0.82) and copper (r=0.64) in the topsoil layer is interpretable (Appendix D-2). The depleted nickel content (33 ppm) was reported in site No.124 possessing abnormally elevated content of organic matter (22.6%). Such reverse behavior of nickel and organic matter is documented by their negative correlation (r=-0.41). The lower content of nickel in the subsoil layer is controlled by the higher carbonate content where they are negatively correlated (r=-0.49). The close association of nickel with the lithogenic clay fraction is thus provable; this result is confirmed by the strong positive correlation between the two variables (r=0.77).

The nickel concentrations estimated in the examined wadi deposits (Table 12)

fluctuate in the range 34-54 ppm (mean=47, median=48 ppm). Nickel content is less variable in the wadi deposits being cover a narrow range of concentrations (sd.=6). The positive correlation of nickel with iron (r=0.58), cobalt (r=0.51) and copper (r=0.35) and its negative correlation with the organic matter (r=-0.58) may reflect its association with these metals in the lithogenic fraction.

The nickel concentrations estimated in the lands applied for wastewater

disposal at El-Kola (ponds and wetlands) (Table 13) display a relatively wide range varying from 35 to 123 ppm (mean=70, median=62 ppm), as indicated from the higher value of standard deviation (sd.=25). Such level of nickel, on the

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average, is considerably lower than that of the cultivated floodplain (p=0.012) and significantly higher than that of the wadi deposits (p<0.001). The negative correlation of nickel with clay (r=-0.50), carbonate (r=-.048) and cadmium (r=-0.43), and its positive correlation with the organic matter (r=0.63), iron (r=0.59), chromium (r=0.67), lead (r=0.67), zinc (r=0.64) and copper (r=0.71) (Appendix D-4) may reflect its effect by both the geogenic characteristics of sediments and the anthropogenic supply from the wastewater disposal practice. The high rate of nickel accumulation in some samples might be attributed to the effect of the nearby Pliocene clay (see Omer, 1996).

The total nickel content (Table 14) estimated in the topsoil layer of the lands

applied for wastewater disposal at El-Dair (farmlands) ranges from 28 to 59 ppm (mean=40, median=39 ppm, sd.=8). In the subsoil layer, nickel values range between 20 and 49 ppm (mean=37, median=38 ppm, sd.=8). No significant difference was found in the nickel level through the topsoil and subsoil layers (p=0.222). The total nickel content of both the topsoil and subsoil layers are significantly lower than that of the wadi deposits (p=0.010 and 0.001 respectively); the matter which is controlled principally by the dilution effect of organic matter.

In the topsoil layer of the wastewater farmlands, nickel is positively

correlated (Appendix D-5) with lead, zinc, copper, clay and organic matter (r=0.60, 0.73, 0.85, 0.32 and 0.22, respectively). Contrarily, it shows negative correlation with carbonate and cadmium (r=-0.18 and –0.12, respectively). Such behavior reflects the effect of human activities at the topsoil layer as a result of the continuous disposal of wastewater practice. In the subsoil layer, nickel is positively correlated with clay, iron, cobalt, and copper (r=0.44, 0.48, 0.48 and 0.75, respectively), while it is negatively correlated with cadmium, carbonate and organic matter (r=-0.59, -0.59 and –0.16 respectively). This pattern follows the geogenic natural behavior of nickel in the subsoil layer.

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The total nickel concentration measured in the surficial sediments of the wastewater ponds at El-Dair (Table 14) varies from 25 to 67 ppm (mean=43, median=41 ppm, sd.=14). It is positively correlated (Appendix D-4) with iron, cobalt, chromium, copper and clay content (r=0.78, 0.81, 0.51, 0.54 and 0.48 respectively), while it is negatively correlated with manganese (r=-0.46). These data may reveal the lithogenic parentage of nickel that follows the distribution pattern of the clay content.

5.1.2.5 Chromium (Cr)

Chromium readily substitutes for iron and it is, therefore, a common constituent of mafic and ultramafic rocks. Average concentration in soil is about 100 ppm. A wide variation in the chromium content of the soil was reported with a mean value for world soil of 84 ppm (McGrath, 1995). Berrow and Reaves (1986) recorded a concentration of 62 ppm for chromium in Scottish soils, while McGrath and Loveland (1992) reported that chromium concentration of the topsoil in England and Wales was 34 ppm. The mean content of chromium in soils is 43 ppm with low mobility (Adriano, 1986). Coarse loamy, sandy, and peaty soils contain less than the clay-rich soil (McGrath, 1995). Kabata-Pendias and Pendias (1992) reported that the grand mean of chromium content is reported to be 54 ppm for surface soils of USA and 65 ppm for worldwide soils. Chromium average level in European soils ranges between 6.4 and 59 ppm in sandy soils, and between 13.2 and 27.8 ppm in clay-rich soils (European Commission, Joint Research Center, 2000). Zaki et al. (2001) reported that chromium has the average concentration of 137 ppm, in their studies of young alluvial sediments of Egypt.

Assuming the present study, the box-whisker graph displayed in figure (31)

exhibits the minimum, maximum, median, lower quartile (25%) and upper quartile (75%) of chromium content among the concerned landuses. A geochemical contour map showing the spatial distribution of chromium through the study area is displayed in figure (32).

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The total content of chromium in the topsoil layer of the cultivated floodplain (Table 10) falls in the range 100-192 ppm (mean=148, median=147 ppm, sd.=21). On the other hand, the total chromium concentration of the subsoil layer varies from 113 to 215 ppm (mean=160, median=155 ppm, sd.=21). Although insignificant statistical difference was reported in the chromium content through the cultivated floodplain along the eastern and western sides of the Nile Valley, a significant higher level was found in the subsoil layer relative to the topsoil one (p=0.024). Zaki et al. (2001) reported that chromium has the average concentration of 137 ppm in the young alluvial sediments. On the other hand, the total chromium content of the cultivated floodplain is significantly higher than that reported for the average shale (90 ppm) by Turekian and Wedepohl, (1961) as well as that reported by Kabata-Pendias and Pendias (1992) and McGrath (1995) for the worldwide soils (65 and 84 ppm, respectively). Such relative higher content of chromium in the floodplain is attributed to its elevated level in the parent source rocks particularly the basaltic rocks of the Ethiopian plateau, where chromium is mainly present substituting iron in the structure of ferromagnesian silicate minerals.

Regarding the interrelation between the total chromium content in the

cultivated floodplain and the soil characteristics (Appendix D-1), no significant correlation was observed with the amount of clay fraction, carbonate and organic matter. However, a positive correlation was recorded with iron, cobalt and nickel in both the topsoil and subsoil layers.

However, the estimated chromium values in the topsoil layer of the

reclaimed lands (Table 11) range from 94 to 243 ppm (mean=145, median=138 ppm, sd.=122). On the other hand, the subsoil layer possesses chromium content varying from 68 to 200 ppm (mean=131, median=131 ppm, sd.=33). No significant difference was reported in chromium content through the topsoil and subsoil layers (p=0.085).

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In the topsoil layer of the reclaimed lands, chromium shows a significant positive correlation with iron, cobalt, nickel and copper (r=0.58, 0.45, 0.34 and 0.33, respectively) and to a less extent clay content (r=0.27). It has a significant negative correlation with carbonate and cadmium (r=-0.48 and -0.38, respectively), whereas it displays a very weak relation with organic matter, lead and zinc (Appendix D-2). This behavior may reflect the natural association of chromium with the former metals in these sediments without a marked influence from the reclamation practice. In the subsoil layer, chromium possesses a significant positive correlation with iron, manganese, cobalt and nickel (r=0.68, 0.70, 0.44 and 0.49, respectively), while it is negatively correlated with cadmium and carbonate (r=-62 and -0.52, respectively). Such behavior of chromium reflects its geogenic generation in the subsoil layer and that it is incorporated principally in the non-calcareous clay fraction. So, the carbonate fraction has a dilution effect on the distribution of chromium.

With respect to the investigated wadi deposits (Table 12), the total

chromium content is oscillating in the range 64-280 ppm (mean=156, median=150 ppm, sd.=53). No significant difference was reported in the chromium concentration through the eastern and western sides of the Nile Valley (p=0.863). The total chromium level in the wadi deposits, on the average, is relatively close to that reported in both the cultivated floodplain and reclaimed lands. Chromium shows a positive correlation with iron and cobalt (r=0.41 and 0.49, respectively) and to a less extent copper and manganese (Appendix D-3), whereas it has a significant negative correlation with carbonate (r=-0.54) suggesting that the major part of chromium is included in the fine argillaceous fraction rather than the calcareous fraction.

Assuming the total chromium content (Table 13) in the lands applied for

wastewater disposal at El-Kola (ponds and wetlands), it is oscillating in the range 85-296 ppm (mean=172, median=176 ppm). It displays a wide range of concentration as indicated from the higher value of standard deviation (sd.=56). Such level of chromium, on the average, is significantly higher than that of the

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cultivated floodplain (p=0.024), whereas it is considerably close to that of the nearby wadi deposits (p=0.344). The strong positive correlation of chromium (Appendix D-4) with iron, nickel, cobalt and copper (r=0.74, 0.67, 0.38 and 0.71, respectively) and its significant negative correlation with carbonate and cadmium (r=-0.81 and -0.73, respectively) suggest its principal incorporation in the fine non-calcareous fraction.

With regard to the lands applied for wastewater disposal at El-Dair

(Table 14), the total content of chromium in the topsoil layer of the wastewater farmlands falls in the range 85-179 ppm (mean=135, median=139 ppm, sd.=30). On the other hand, the total chromium concentration of the subsoil layer varies from 65 to 415 ppm (mean=176, median=162 ppm, sd.=85). An insignificant statistical difference was reported in the chromium content through the topsoil and subsoil layers (p=0.092).

In the topsoil layer of the wastewater farmlands, chromium shows a

significant positive correlation (Appendix D-5) with iron and cobalt (r=0.42 and 0.48, respectively) and to a less extent manganese. It has a significant negative correlation with the organic matter (r=-0.61) but less significant correlation was found with zinc and copper. This behavior may reflect the natural association of chromium with the lithogenic metals in these sediments without a discernible any influence by the wastewater disposal practice. In the subsoil of the wastewater farmlands, chromium possesses a significant positive correlation with iron, zinc and copper (r=0.63, 0.61 and 0.47, respectively) and to a less extent manganese, nickel and cobalt. It shows a significant negative correlation with cadmium and carbonate (r=-0.56 and -0.69, respectively).

The chromium concentration in the surficial sediments of the wastewater

ponds at El-Dair (Table 14) ranges from 94 to 222 ppm (mean=141, median=141 ppm, sd.=36). No significant variability was found in the total chromium content compared with the nearby wadi deposits (p=0.376). Chromium has a negative correlation (Appendix D-4) with carbonate and cadmium (r=-0.36 and -0.44,

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respectively). The strong positive correlation of chromium with clay, iron, cobalt and nickel (r=0.67, 0.45, 0.50 and 0.51, respectively), as well as organic matter and lead (r=0.44 and 0.65, respectively), reflects the influence of both the geogenic non-calcareous composition of sediments and the anthropogenic activities related to the wastewater disposal practice.

5.1.2.6 Lead (Pb)

Lead is present in geologic materials and soils in various contents. Lead average level in European soils ranges between 10.5 and 35 ppm in sandy soils, and between 12 and 36 ppm in clay soils (European Commission, Joint Research Center, 2000). Estimates of lead in normal soils are variable; Nriagu (1978) has reported the mean level as 17 ppm and Ure and Berrow (1982) have reported 29 ppm. Holmgren et al. (1993) and Wixson and Davis (1994) stated that soils with lead levels above 20 ppm are primarily the result of lead contamination.

Regarding the situation of lead under Egyptian environment,

Abdel-Shakour (1982) mentioned that lead concentrations in the cultivated soil of Upper Egypt, away from pollution source, are in the range of 9-21 ppm, with a mean value of 14.9 ppm. El-Hussieny (1995) found that the lead in El-Gabal El-Asfar wastewater farmlands ranged from 53.5 to 226 ppm.

Regarding the present study, the minimum, maximum, median, lower

quartile (25%) and upper quartile (75%) of the lead content through the various landuses are displayed in the box-whisker graph displayed in figure (33). The geochemical contour map given in figure (34) shows the spatial distribution pattern of lead throughout the investigated area.

The total lead content of the cultivated floodplain (Table 10) ranges from

16 to 52 ppm (mean=24, median=23 ppm, sd.=6) and from 17 to 28 ppm (mean=22, median=22ppm, sd.=3) in the topsoil and subsoil layers, respectively. Generally, the estimated average content of lead in the cultivated floodplain is strongly comparable with that reported for the average shale (23 ppm by

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Alloway, 1990; 20 ppm by Turekian and Wedepohl, 1961). Also, the average content of lead in the cultivated floodplain is in general agreement with the values estimated for the uncontaminated soils (29 ppm by Ure and Berrow, 1982; 17 ppm by Nriagu, 1978). Such lead contents, which are identical to the average shale and the uncontaminated soils, suggest that the distribution pattern of lead is controlled principally by the natural sediment composition. Only four samples belonging to the topsoil layer displayed relative higher lead content being exceed 30 ppm, implying that the anthropogenic impact on the lead addition is occasional. No marked variability of lead level was reported among the topsoil and subsoil layers of the cultivated floodplain (p=0.284). The abnormal lead value (52 ppm) reported in the topsoil layer at site No. 115 reflects the anthropogenic impact under the exceptional situation at this site as stated above.

In the topsoil layer, lead exhibits very strong positive correlation

(Appendix D-1) with zinc and copper (r=0.78 and 0.77, respectively), while it is negatively correlated with cobalt, iron and manganese (r=-0.42, -0.40 and -0.35, respectively). The close association of lead with zinc and copper in the topsoil layer may confirm their occasional influences by the agricultural practice. Insignificant correlation was found between lead and both the clay fraction, carbonate and organic matter content. The subsoil layer of the cultivated floodplain exhibits a narrow range of lead and all samples possess values less than 30 ppm. In addition, lead shows no significant correlation with the other variables even zinc and copper. This performance reflects the natural independent behavior of lead and indicates that the anthropogenic effect on its distribution pattern is extremely reduced in the subsoil layer.

Regarding the lead content in the reclaimed lands (Table 11), it varies from

12 to 248 ppm (mean=29, median=22 ppm, sd.=40) in the topsoil layer. In the subsoil layer, it ranges between 18 and 148 ppm with a mean value of 30 ppm (median=26 ppm, sd.=22). On the average, no marked difference in lead contents was reported through the topsoil and subsoil layers (p=0.943). The majority of samples show lead content fluctuating around its level in the

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average shale and the uncontaminated soils. Although some samples have slightly higher lead content, only one site (No. 124) shows abnormally elevated levels (248 and 148 ppm in the topsoil and subsoil layers, respectively). This site is located very close to the lands applied for wastewater disposal at El-Dair and, therefore, the anthropogenic contamination related to this practice is responsible for elevating this lead level. Lead is very strong correlated with the organic matter content (Appendix D-2) in both the surface and subsurface layers (r=0.95 and 0.91, respectively) confirming the occasional anthropogenic impact.

The lead concentration in the wadi deposits (Table 12) ranges from

19 to 36 ppm with a mean value of 27 ppm (median=27 ppm, sd.=5). No significant variability was recorded in the lead distribution throughout the studied wadi deposits even along the eastern and western sides of the Nile Valley (p=0.658). Lead shows significant positive correlation with iron, cobalt, nickel and manganese (r=0.64, 0.57, 0.51 and 0.47, respectively). This may reflect their association particularly in the fine detrital derived from the nearby Pliocene clays.

Concerning the total lead concentration in the lands applied for wastewater

disposal at El-Kola (Table 13), it varies from 16 to 176 ppm (mean=59, median=31 ppm, sd.=55). The average content of lead in these sediments is significantly higher than its level in sediments of the cultivated floodplain and wadi deposits (p<0.001 and 0.022, respectively). The high value of standard deviation reflects the wide range and extreme variability of lead in these sediments. The significant positive correlation (Appendix D-4) of lead with organic matter content (r=0.85), zinc (r=0.88), copper (r=0.82) and nickel (r=0.67) and its negative correlation with the clay (r=-0.47) emphasize its anthropogenic supply as loaded by raw wastewater and the associated biosolids.

The total lead content estimated in the topsoil layer of the wastewater

farmlands at El-Dair (Table 14) fluctuates between 26 and 186 ppm (mean=81, median=64 ppm, sd.=54). In the subsoil layer, it varies from 21 to 111 ppm (mean=45, median=37 ppm, sd.=25). The total lead content exhibits significant

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difference between the topsoil and subsoil layers (p=0.025). Although its wide range in soils of these farmlands, the average total lead content is significantly higher than that reported for the cultivated floodplain and wadi deposits (p<0.001 and 0.002, respectively), whereas it is very closely akin to that of the lands applied for wastewater disposal at El-Kola. Regarding the inter-variable relationship in the topsoil layer of the farmlands (Appendix D-5), the total lead is positively correlated with zinc, copper, clay fraction and organic matter (r=0.76, 0.76, 0.66 and 0.61, respectively). In the subsoil layer, lead shows insignificant correlation with clay, iron and organic matter. This performance reflects the anthropogenic impact of wastewater disposal at the surface layer, which is minimized through the subsoil layer.

The total lead level estimated in sediments of the wastewater ponds at

El-Dair (Table 14) ranges between 23 and 306 ppm (mean=104, median=61 ppm, sd.=98). It is clear that lead covers a wide range of concentration as indicated from the higher value of standard deviation. The average lead content in these sediments is extremely similar to that of the topsoil layer of the farmlands (p=0.436), whereas it is comparatively higher than that of the other landuses. With respect to its relation with the other variables (Appendix D-4), lead exhibits the strongest positive correlation with the organic matter content (r=0.71) confirming the effect of the raw wastewater on the lead accumulation.

5.1.2.7 Zinc (Zn)

Total zinc content of soil is largely dependent on the composition of the parent rock material (Graham, 1953; Swaine and Mitchell, 1960; Wells, 1960; Sillanpaa, 1972; Kabata-Pendias and Pendias, 1984). Zinc contents in shales and clayey sediments fall in the range 80-120 ppm (Kabata-Pendias, 1984). Ravikovitch et al. (1968) found that total zinc content of some calcareous soils ranges from 38 to 194 ppm.

The total zinc content of soils usually ranges from 10 to 300 ppm

(Sillanpaa, 1972; Lindsay, 1972). Kabata-Pendias and Pendias (1984), reported

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values of 17-125 ppm zinc as background content of a large number of surface soils in different countries. Later, they also calculated the world wide mean of zinc to be 64 ppm (Kabata-Pendias and Pendias, 1992). Eisler (1993) reported that background concentrations of zinc in soils or sediments seldom exceed 200 ppm.

Zinc content in the alluvial soils of Egypt ranges from 23 to 194 ppm with an

average of 77.7 ppm (El-Sayed, 1971). The alluvial soils comprise zinc levels of 130–320 ppm, while the calcareous and sandy soils contained low or medium values ranging between 30 and 90 ppm (El-Halawany ,1978). Abou El-Khir (2000) stated that total zinc levels varied widely from 41 to 141 ppm with an average of 76 ppm.

Shuman (1978) pointed out that zinc content was higher in the fine-textured

and higher organic matter soils than in the coarse-textured soils. El-Toukhy (1995) reported that total zinc content in recent Nile alluvial deposits is positively correlated with each of clay and organic matter.

In the current study, the box-whisker graph given in figure (35) shows the

minimum, maximum, median, lower quartile (25%) and upper quartile (75%) of zinc content through the considered landuses. The spatial distribution of zinc through the study area is displayed in figure (36).

The total zinc content in the soil samples collected from the studied

cultivated floodplain (Table 10) ranges between 90 and 1249 ppm (mean=197, median=1625 ppm, sd.=189) in the topsoil layer, while it varies between 99 and 469 ppm (mean=160, median=146 ppm, sd.=66) in the subsoil layer. The abnormal elevated level of zinc (1249 ppm) was reported at site No. 115. This site is located adjacent to some private workshops at the western side of Sohag city (see Fig. 4). So, the higher zinc content at this site is most probably related to such industrial activities. The total zinc content of the investigated soil samples, excluding the mentioned anomalous value, comes in harmony with the range estimated by Lindsay (1972) for the non-polluted North American soils

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(<300 ppm). On the other hand, the median value of the total zinc in the inspected soils is relatively higher than that recorded in some previous literatures (e.g. El-Sokkary, 1979, 76 ppm; Ghoneim et al., 1984a, 94 ppm; Attia, 1988, 62 ppm; and Ibrahim et al., 2001, 53 ppm). The elevated levels of the total zinc content in the present study may be attributed to the analytical technique, where complete acid digestion was performed on the fine fraction (<63µm). According to the present results of zinc content, the studied soils are considered to belong to the high level class (see Chapmann, 1965).

However, no significant variability was found in the total zinc content

throughout the topsoil and subsoil layers of the cultivated floodplain (p=0.270). In the topsoil layer, total zinc displays a close positive relation (Appendix D-1) with copper and lead (r=0.94 and 0.78 respectively). On the contrary, zinc shows significant negative correlation with cobalt, iron and manganese (r=-0.61, -0.50 and -0.43, respectively). No important relationship was detected with the clay fraction, organic matter or carbonates. This behavior reflects the effect of human activities on the former metals at the topsoil layer as a result of the continuous farming practice. Regarding the distribution pattern and behavior of zinc in the subsoil layer, it was found that it has insignificant correlation with the different examined metals even the anthropogenically-affected ones. This implies that the influence of anthropogenic activities is minimized through the subsoil layer.

In the topsoil layer of the reclaimed lands (Table 11), zinc possesses wide

range varying from 89 to 401 ppm (mean=156, median=131 ppm, sd.=115), whereas it varies from 88 to 275 ppm (mean=136, median=123 ppm, sd.=42) in the subsoil layer. On the average, values of the total zinc in the reclaimed lands are relatively low compared with the cultivated floodplain. Only one sample (No. 71) displayed abnormal zinc content (401 ppm). This sample is located in a site occasionally used for manual wastewater disposal; the higher content of organic matter (8.32%) in this sample confirms such anthropogenic practice. With respect to the topsoil layer, zinc displays positive correlation (Appendix D-2) with the organic matter and lead content (r=0.61 and 0.48, respectively), whereas it is negatively correlated with cadmium, iron and cobalt (r=-0.51, -0.40,

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and –0.37, respectively). Accordingly, the behavior of zinc follows the distribution pattern of organic matter. On the other hand, no significant correlation was reported between zinc and the other variables in the subsoil layer. Such independent behavior of zinc is caused by the very low content of organic matter and the less variable content of clay fraction.

The mean zinc content of wadi deposits (Table 12) is 153 ppm

(median=160 ppm, sd.=33) where its values fall in the range 76-195 ppm. Zinc content displays no spatial trend throughout the studied wadi deposits, where no important variability was found even along the eastern and western sides of the Nile Valley (p=0.239). This behavior is controlled by the elevated content of carbonate and the very low content of organic matter. The total zinc content is positively correlated (Appendix D-3) with cobalt, copper, iron, manganese and the clay content (r=0.43, 0.41, 0.39, 0.35 and 0.27, respectively). On the other hand, it is negatively correlated with cadmium, carbonate and organic matter (r=-0.42, -0.34 and -0.32, respectively). Such behavior of zinc reflects its natural behavior in the wadi deposits where no anthropogenic activities were documented.

The zinc concentrations (Table 13) estimated in the lands applied for

wastewater disposal at El-Kola (ponds and wetlands) display a wide range varying from 111 to 794 ppm (mean=290, median=173 ppm) as indicated from the higher value of standard deviation (sd.=218). Such level of zinc, on the average, is considerably higher than that of the cultivated floodplain and wadi deposits (p=0.004 and 0.018, respectively). The significant positive correlation (Appendix D-4) of zinc with organic matter content (r=0.90), lead (r=0.88) and copper (r=0.78) and its negative correlation with the clay content (r=-0.47) and cobalt (r=-0.52) emphasize its anthropogenic supply as loaded by wastewater and the associated biosolids. The carbonate fraction, to a less extent, acts as a dilution factor affecting the zinc content reversely (r=-0.27).

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The total zinc content (Table 14) estimated in the topsoil layer of the lands applied for wastewater disposal at El-Dair (farmlands) ranges from 143-1429 ppm (mean=462, median=266 ppm, sd.=347). In the subsoil layer, zinc values range between 120 and 486 ppm (mean=235, median=179 ppm, sd.=114). It is seemed that, the topsoil layer has a wider range of zinc concentration than the subsoil layer as indicated from the higher value of standard deviation, which follows the highly variable content of organic matter in this layer. The total zinc content exhibits a significantly elevated level in the topsoil than the subsoil layer (p=0.023). The total zinc content of both layers is significantly higher than that of the adjacent wadi deposits (p=0.001 and 0.008, respectively), this matter reveals that the wastewater disposal practice has caused increase of zinc content in these sediments.

In the topsoil layer of the stated wastewater farmlands, zinc is positively

correlated (Appendix D-5) with clay fraction, copper, lead, nickel, manganese and organic matter (r=0.25, 0.96, 0.76, 0.73, 0.68 and 0.71, respectively). It shows negative correlation with carbonate (r=-0.49) and cobalt (r=-0.50). Such behavior reflects the effect of human activities at the topsoil layer as a result of the continuous disposal of wastewater and its byproducts and reveals the dilution influence of carbonate. The subsoil layer of the farmlands behaves similarly as the topsoil layer.

The total zinc concentration measured in the surficial sediments of the

wastewater ponds at El-Dair (Table 14) varies from 165 to 1040 ppm (mean=427, median=319 ppm, sd.=286). It displays a wide range of concentration as indicated from the high value of standard deviation. The estimated zinc content in the wastewater ponds at El-Dair, on the average, is significantly higher than that reported for the subsoil layer of the wastewater farmlands and the nearby wadi deposits (p=0.022 and 0.001, respectively), whereas it is very closely akin to that of the topsoil layer of the wastewater farmlands (p=0.761).

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5.1.2.8 Copper (Cu)

Copper is an abundant trace element found in a variety of rocks and minerals (Bowen, 1985). The amount of copper found in soil is generally less than that in the parent rock material due to the loss of copper by weathering of sulfides and leaching (Goldschmidt, 1954). The background levels of copper in soil and sediment result from Cu-containing parent rock, and thus vary according to local geology (Flemming and Trevors, 1989). Swaine (1955) has quoted several workers who estimated that the total copper content ranges from 1 to 100 ppm in the normal agricultural soils of the world. Neelakaktan and Mehta (1961) found that copper in soil of Western India varied from 11.0 to 175.5 ppm with an average of 55.8 ppm. According to Singh et al. (1969) the total Cu contents in some soils of India were in the range of 76-148 ppm. Reuther (1957) indicated that the soil content of total copper in most mineral soils usually falls within a range of 25-60 ppm.

Diverse range was reported for total copper in the soils of Egypt.

According to Kishk et al. (1973), it varies between 30.5 and 72.3 ppm. The recorded average content of total copper in the soil of Assiut was 56.4 ppm (Abd El-Razek, 1969). Approximately similar values for total copper were found in Upper Egypt, where soils contained from 10.5 to 102.8 ppm with an average of 48.3 ppm (Ghoneim et al., 1984b). Ismaeil (1993) reported that total copper content ranged between 5.1 and 78 ppm in various calcareous soils. A range of 6-62 ppm was also reported by Aboulroos and Abdel Waheed (1978) for soils of Egypt. El-Mowilhi and El-Abaseri (1979) found that total copper content in the soils of Kafr El-Sheikh Governorate ranged from 81-140 ppm. Attia (1988) found that total copper content in the soils of Aswan and El-Minia ranged from 8 to 127 ppm with an average of 48.9 ppm. Rashad et al. (1995) found that total copper in the normal alluvial soils of the Nile Delta ranged between 41 and 78 ppm with an average of 66 ppm. El-Toukhy (1995) reported that total copper for the alluvial soils of Nile Delta ranged between 62 and 88.5 ppm with an average of 72.3 ppm.

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The minimum, maximum, median, lower quartile (25%) and upper quartile (75%) of the copper content in the study area are displayed in the box-whisker graph shown in figure (37). The spatial distribution pattern of copper through the study area is shown in the geochemical contour map given in figure (38).

The total copper content of the studied cultivated floodplain (Table 10),

ranges from 55 to 244 ppm (mean=76 ppm, median=70 ppm, sd.=31) in the topsoil layer, whereas it varies between 54 and 84 ppm (mean=74 ppm, median=76 ppm, sd.=7) in the subsoil layer. The average copper concentration is strictly comparable with that reported by Baker and Chesnin (1975) for the average lithosphere (70 ppm). Although there is insignificant difference in the copper content between the topsoil and subsoil layers (p=0.746), a mild downward increase was observed in most sites. Only one sample (No. 115) from the topsoil layer displayed abnormal level of copper (244 ppm). This site has a special position being located close to some private workshops, as mentioned above. So, the higher copper content at this site is most probably related to such industrial activities.

Regarding the interrelation between the total copper content in the topsoil

layer of the cultivated floodplain and the soil characteristics (Appendix D-1), no significant correlation was observed with the amount of clay fraction, carbonate or organic matter. On the other hand, the total copper content shows a significant positive correlation with zinc and lead (r=0.94 and 0.77, respectively), whereas it displays a significant negative correlation with iron, manganese and cobalt (r=-0.46, -0.43 and –0.64 respectively). In the subsoil layer, copper displays a dramatically different behavior where it has a significant positive correlation with the clay fraction, organic matter, iron, manganese and nickel (r=0.37, 0.48, 0.32, 0.35 and 0.42, respectively). The behavior of copper throughout the cultivated floodplain is clearly controlled by both the natural soil composition and the anthropogenic activities. The positive correlation of copper with iron, manganese, cobalt and nickel in the subsurface zone (Appendix D-1) reflects their geogenic source where they are naturally co-associated in these sediments. The negative correlation of copper with iron, manganese, cobalt and

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nickel and its strong positive correlation with zinc and lead in the topsoil layer suggest that it is relatively affected by the various farming practices and other anthropogenic activities.

With respect to the reclaimed lands (Table 11), the total copper content

varies between 26 and 89 ppm (mean=61, median=59 ppm, sd.=53), and from 25 to 115 ppm (mean=46, median=39 ppm, sd.=20) in the topsoil and subsoil layers, respectively. The total copper content of the topsoil layer is significantly higher than that of the subsoil horizon (p<0.001); the matter which is controlled principally by the diverse nature of the parent material and lithological characteristics of the two layers. In addition, the topsoil layer of the reclaimed lands displays lower copper content than the cultivated floodplain as governed by the dilution effect of carbonate in the former one.

In the topsoil of the reclaimed lands, statistical analysis proved a significant

positive correlation (Appendix D-2) between total copper and both nickel, cobalt and iron (r=0.64, 0.55 and 0.39, respectively). With respect to the relationship between total copper and soil properties, significant positive correlation (r=0.45) was observed with the amount of the clay fraction, whereas significant negative correlation (r=-0.45) with carbonate was documented. This manner implies that copper is incorporated mainly in the fine non-calcareous fraction. The dilution effect of carbonate on the distribution of copper is thus firmly confirmed. On the other hand, organic matter content has no significant effect on the distribution of total copper in the investigated sediments. In the subsoil horizon, copper exhibits no important correlation with the different estimated metals, with the exception of its positive correlation with nickel (r=0.42). It is significantly correlated with the clay fraction content while almostly unaffected by either organic matter or carbonate. The stated behavior of copper throughout the reclaimed lands implies that it is of geogenic nature and controlled principally by the distribution manner of the clay fraction.

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The total copper concentration in the wadi deposits (Table 12) ranges from 30 to 114 ppm (mean=54, median=46 ppm, sd.=25). In general, wadi deposits posses lower values of copper compared with the cultivated floodplain (p=0.001). The total copper content in the wadi deposits has a significant positive correlation (Appendix D-3) with the clay fraction (r=0.47), whereas it shows insignificant negative correlation with both the organic matter and carbonate. With respect to its interrelation with other metals, copper displays significant positive correlation with iron and cobalt (r=0.55 and 0.45, respectively). Such behavior of copper in the wadi deposits indicates that it is essentially of geogenic source where it is controlled by the compositional characteristics of the non-calcareous fine fraction.

Regarding the distribution pattern of copper in the lands applied for

wastewater disposal at El-Kola (ponds and wetlands) (Table 13), it ranges from 41 to 338 ppm with a mean value of 122 ppm (median=100 ppm, sd.=69). Such level of copper, on the average, is significantly higher than that of the cultivated floodplain and the nearby wadi deposits (p<0.001 and 0.001, respectively). Copper is significantly correlated (Appendix D-4) with organic matter, lead, zinc, nickel, chromium, and iron (r=0.85, 0.82, 0.78, 0.71, 0.38 and 0.35, respectively), while it shows significant negative correlation with cobalt (r=-0.37). Less significant negative correlation was reported with the clay and carbonate. This behavior of copper may reflect its effect by both the geogenic characteristics of sediments and the anthropogenic supply from the wastewater disposal practice. The high rate of copper accumulation in some samples is associated with higher content of organic matter reflecting the improper treatment of wastewater. On the other hand, the lower copper content in other samples may reflect its natural distribution manner as controlled by the lithological characteristics of sediments. Therefore, it is deemed that the total copper level is significantly influenced by the wastewater disposal practice.

With respect to the total content of copper in the lands applied for

wastewater disposal at El-Dair (Table 14), it varies between 25 and 244 ppm (mean=93, median=61 ppm, sd.=61) in the topsoil layer of the wastewater farmlands, whereas it ranges from 17 to 63 ppm (mean=43, median=42 ppm, sd.=13) in the subsoil layer. It is seemed that, the topsoil layer has a wider range

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of concentration than the subsoil layer, as indicated from the higher value of standard deviation (sd.=61), following the high variability of organic matter. The total copper content exhibits significant difference between the topsoil and subsoil layers (p=0.004). The estimated copper content in the topsoil layer of the farmlands, on the average, is markedly higher than that reported for the cultivated floodplain and wadi deposits (p=0.05 and 0.022 respectively). Contrarily, copper in the subsoil layer is significantly lower than that reported for the cultivated floodplain, whereas it is very closely akin to that of the wadi deposits (p<0.001 and 0.114, respectively).

In the topsoil layer of the wastewater farmlands, copper is positively

correlated (Appendix D-5) with zinc, nickel, lead, organic matter and manganese (r=0.96, 0.85, 0.76, 0.67 and 0.49, respectively), but a negative correlation was found with cobalt and carbonate (-0.49, -0.47, respectively). On the other side, copper is positively correlated with nickel, zinc, clay and chromium (r=0.75, 0.59, 0.55 and 0.47, respectively) and negatively correlated with cadmium and carbonate (r=-0.54 and –0.61, respectively) in the subsoil layer. The topsoil layer of the farmlands displays higher copper content than the subsoil layer as governed by the organic matter enrichment, and to a less extent by clay fraction (r=0.30). The copper content in the subsoil is mainly controlled by the natural lithogenic fine fraction as well as the dilution effect of carbonate. Therefore, it is deemed that the copper level is significantly influenced by the wastewater disposal practice on the topsoil layer rather than the subsoil one.

The total copper concentration measured in the surficial sediments of the

wastewater ponds at El-Dair (Table 14) displays a wide range varying from 32 to 223 ppm (mean=83, median=65 ppm) as indicated from the higher value of standard deviation (sd.=54). The estimated copper content in the wastewater ponds at El-Dair, on the average, is very closely akin to that of the topsoil layer of the farmlands (p=0.641), whereas it is significantly higher than that reported for the subsoil layer of the farmlands and the nearby wadi deposits (p=0.009 and 0.056, respectively).

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5.1.2.9 Cadmium (Cd)

The average concentration of cadmium in the Earth’s crust is estimated to be 0.1 ppm (Heinrichs et al., 1980; Bowen, 1979) and 0.15 ppm (Weast, 1969). Concentrations in igneous and metamorphic rocks are generally less than 1 ppm. Concentrations of cadmium in soil range from 0.05 to about 1 ppm. Soils normally contain small amounts of cadmium usually below 1.0 ppm (Swaine, 1955). David and Robert (1973) revealed that the maximum cadmium concentration of uncontaminated soils was 2.4 ppm.

In their survey of some American soils from uncontaminated sites, a range

of 0.01-2.0 ppm with a mean content of 0.27 ppm was reported for a range of 0.01-2.0 ppm by Nriagu (1980). Holmgren et al. (1986) revealed a range of 0.005 to 2.4 ppm with a mean of 0.27 ppm. A survey of soil samples from England and Wales gave a mean cadmium content of 0.8 ppm (McGrath and Loveland, 1992). Kabata-Pendias and Pendias (1992) concluded that cadmium content in soils, reported from most analytical surveys, shows background levels in the range 0.06-1.1 ppm with a worldwide mean of 0.53 ppm.

El-Sokkary and Lag (1979) reported values of total cadmium ranging from

0.01 to 0.65 ppm with an average of 0.34 ppm for the soils of Egypt. Rashad et al. (1995) reported that the normal level of cadmium in alluvial soils of the Delta ranged between 0.7 and 1.4 ppm.

Considering the present study, the box whisker graph given in figure (39)

shows the minimum, maximum, median, lower quartile (25%) and upper quartile (75%) of the cadmium content through the study area. A geochemical contour map displaying the distribution pattern of cadmium through the study area is displayed in figure (40).

The total cadmium values estimated in the topsoil layer of the cultivated

floodplain (Table 10) range from 0.62 to 0.94 ppm (mean=0.77, median=0.77 ppm), whereas it varies between 0.67 to 0.99 ppm (mean=0.79, median=0.78 ppm)

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in the subsoil layer. Cadmium is fluctuated within a narrow range in both the topsoil and subsoil layers reflecting its low variability, as indicated from the low values of standard deviation (0.08 and 0.07, respectively). No significant difference was recorded in the cadmium level among the topsoil and subsoil layers (p=0.423).

The total cadmium content of the cultivated floodplain is considerably

higher than that of the average shale (0.3 ppm) reported by Turekian and Wedepohl (1961). In addition, the current level of cadmium is relatively elevated compared with its average concentration in the uncontaminated soils of the USA (mean=0.27, median=0.20 ppm); meanwhile, a very wide range of cadmium content was reported (0.005-2.4 ppm) in these soils (Holmgren et al., 1986) as controlled by the geogenic and anthropogenic circumstances. Comparatively elevated level of cadmium in the cultivated floodplain may be ascribed to the widespread use of the phosphate fertilizers. Because of its relative mobility under the surficial conditions, a considerable portion of cadmium might be possible to migrate downward into the subsoil layer.

In the topsoil layer of the cultivated floodplain, cadmium is positively

correlated with zinc, copper, lead and carbonate (r=0.36, 0.31, 0.27 and 0.37, respectively), whereas it shows very weak relation with the other variables (Appendix D-1). On the other side, it displays a negative correlation with iron and copper (r=-0.54 and –0.31, respectively) but shows a positive correlation with carbonate content (r=0.37) in the subsoil layer. This reveals that carbonate is the main carrier of cadmium and a significant part of cadmium may be of anthropogenic source related to the agricultural practice.

With respect to the reclaimed lands (Table 11), the total cadmium content

varies between 0.68 and 1.55 ppm (mean=0.92, median=0.86 ppm, sd.=0.21), and between 0.73 and 2.05 ppm (mean=1.25, median=1.16 ppm, sd.=0.35) in the topsoil and subsoil layers, respectively. The total cadmium content of the topsoil layer is significantly lower than that of the subsoil horizon (p<0.001); the matter

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which is controlled principally by the diverse nature of the parent material and lithological characteristics of the two layers, as mentioned above. In addition, the topsoil layer of the reclaimed lands displays higher cadmium content than the cultivated floodplain (p<0.001), as governed by the effect of elevated carbonate in the former one (p<0.001).

The positive correlation of cadmium with zinc and lead (r=0.36 and 0.11,

respectively) and its strongest positive correlation with carbonate (r=0.68) in the topsoil layer of the reclaimed lands suggest that it is relatively affected by the anthropogenic activities (severe addition of fertilizers), beside the geogenic effect following the content of carbonate fraction. So, the behavior of cadmium throughout the topsoil of the reclaimed lands is clearly controlled by both the natural soil composition and the anthropogenic activities. The highly significant positive correlation of cadmium with carbonate (r=0.85) and the very weak correlation with lead and zinc in the subsurface zone (Appendix D-2) reflects its geogenic source. Generally, the stated manner of cadmium throughout the reclaimed lands implies that the total content of carbonate is the main variable controlling its behavior.

The cadmium concentration in the wadi deposits (Table 12) ranges from

0.94 to 1.77 ppm with a mean value of 1.31 ppm (median=1.30 ppm, sd.=0.19). No significant variability was recorded in the cadmium distribution throughout the studied wadi deposits even along the eastern and western sides of the Nile Valley (p=0.244). Cadmium shows the strongest correlation with carbonate (r=0.69). This behavior indicates that cadmium follows the carbonate content where it is incorporated mainly in the fine calcareous fraction.

With respect to the lands applied for wastewater disposal at El-Kola

(Table 13), the total cadmium values in the surficial sediments range from 0.84 to 2.00 ppm (mean=1.72, median=1.16 ppm). Cadmium is fluctuated within a narrow range reflecting its low variability, as indicated from the low value of standard deviation (sd.=0.31). The total cadmium content displays higher

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concentration than the cultivated floodplain (p<0.001) as governed by the effect of elevated carbonate in these sediments. No significant difference was recorded in the cadmium level with the nearby wadi deposits (p=0.645). The total cadmium content of the present sediments is considerably higher than that of the average shale (0.3 ppm) reported by Turekian and Wedepohl (1961). Cadmium is positively correlated (Appendix D-4) with clay and carbonate (r=0.46 and 0.93, respectively). On the other side, cadmium displays a negative correlation with iron, nickel and chromium (r=-0.52, -0.43 and -0.73, respectively). The behavior of cadmium throughout the lands applied for wastewater disposal at El-Kola is thus controlled by the natural sediment composition where it is incorporated mainly in the fine calcareous fraction.

With respect to the lands applied for wastewater disposal at El-Dair

(Table 14), the total cadmium content varies between 0.51 and 1.50 ppm (mean=0.97, median=0.95 ppm), and between 0.54 and 2.11 ppm (mean=1.15, median=1.06 ppm) in the topsoil and subsoil layers of the wastewater farmlands, respectively. No significant variability was recorded in the cadmium distribution throughout the topsoil and subsoil layers (p=0.164).

The highly significant positive correlation of cadmium with carbonate in

surface and subsurface layers (r=0.69 and 0.95, respectively) and the negative correlation with organic matter, zinc, lead and copper (Appendix D-5) reflects its geogenic source. Generally, the stated manner of cadmium throughout the wastewater farmlands implies that the total content of carbonate is the main variable controlling its behavior.

The total cadmium concentration in the surficial sediments of the

wastewater ponds at El-Dair (Table 14) ranges from 0.85 to 1.40 ppm with a mean value of 1.04 ppm (median=1.02 ppm, sd.=0.16). No significant variability was recorded in the cadmium concentration throughout the studied surficial sediments of the wastewater disposal at El-Dair. Also, the estimated cadmium content in the ponds, on the average, is markedly lower than that reported for the

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wadi deposits (p<0.001) as governed by the dilution effect of the elevated organic matter content in the former (mean=17.7%). Cadmium shows positive correlation (Appendix D-4) with carbonate (r=0.34), while it is negatively correlated with the clay and organic matter content (r=-0.55 and -0.32, respectively). These data prove the lithogenic parentage of cadmium as contained in the calcareous fraction; the dilution influence of the organic matter is also documented.

Table (10): Summary of descriptive statistics for the total heavy metals

content (ppm) in the cultivated floodplain (n= 70)

Cd Cu Zn Pb Cr Ni Co Mn Fe% Depth (cm) 0.77 76 197 24 148 68 35 1312 6.66 00-20 0.79 74 160 22 160 69 38 1378 7.40 20-40

Mean

0.77 70 163 23 147 67 36 1305 6.81 00-20 0.78 76 146 22 155 70 38 1365 7.45 20-40 Median

0.62 55 90 16 100 51 15 604 3.71 00-20 0.67 54 99 17 113 54 31 1055 4.95 20-40 Minimum

0.94 244 1249 52 192 119 43 2193 8.16 00-20 0.99 84 469 28 215 84 44 1885 9.26 20-40 Maximum

0.08 31 189 6 21 11 5 246 0.94 00-20 0.07 7 66 3 21 6 3 150 0.78 20-40 sd. 0.70 66 131 21 132 63 33 1164 6.31 00-20 0.74 71 116 20 144 66 35 1281 7.12 20-40 25% percentile

0.83 77 211 26 166 70 38 1398 7.13 00-20 0.83 79 178 25 171 73 40 1467 7.69 20-40 75% percentile

Table (11): Summary of descriptive statistics for the total heavy metals content (ppm) in the reclaimed lands (n= 65)

Cd Cu Zn Pb Cr Ni Co Mn Fe% Depth (cm) 0.92 61 156 29 145 61 33 1293 6.04 00-20 1.25 46 136 30 131 43 28 968 4.24 20-40 Mean

0.86 59 131 22 138 64 35 1299 6.16 00-20 1.16 39 123 26 131 40 27 1035 3.95 20-40 Median 0.68 26 89 12 94 33 17 694 1.75 00-20 0.73 25 88 18 68 28 21 275 1.29 20-40 Minimum 1.55 89 401 248 243 78 40 3205 12.30 00-20 2.05 115 275 148 200 70 38 1355 7.84 20-40 Maximum 0.21 53 115 40 122 10 6 413 1.82 00-20 0.35 20 42 22 33 11 5 277 1.55 20-40 sd. 0.79 69 171 19 156 57 28 1071 5.28 00-20 0.94 33 101 23 101 35 23 754 3.06 20-40 25%percentile 0.98 12 67 25 32 67 37 1424 6.63 00-20 1.39 52 148 28 156 48 30 1171 5.10 20-40 75%percentile

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Table (12): Summary of descriptive statistics for the total heavy metals content (ppm) in the wadi deposits (n= 17)

Cd Cu Zn Pb Cr Ni Co Mn Fe % 1.31 54 153 27 156 47 29 895 4.12 Mean 1.30 46 160 27 150 48 30 923 4.14 Median 0.94 30 76 19 64 34 21 449 2.54 Minimum 1.77 114 195 36 280 54 35 1181 5.94 Maximum 0.19 25 33 5 53 6 5 209 0.99 sd. 1.19 37 138 23 123 44 25 771 3.40 25% percentile 1.35 58 174 31 161 50 32 1043 4.80 75% percentile

Table (13): Summary of descriptive statistics of the total heavy metals content (ppm)

in the lands applied for wastewater disposal at El-Kola (n=29).

Cd Cu Zn Pb Cr Ni Co Mn Fe % 1.27 122 290 59 172 70 33 1058 4.56 Mean 1.16 100 173 31 176 62 31 850 4.77 Median 0.84 41 111 16 85 35 21 258 1.87 Minimum 2.00 338 794 176 296 123 54 5418 7.00 Maximum 0.31 69 218 55 56 25 8 906 1.32 sd. 1.05 74 148 28 120 48 27 773 3.53 25% percentile 1.41 149 343 52 208 88 37 946 5.70 75% percentile

Table (14): Summary of descriptive statistics of the total heavy metals content (ppm) in the

lands applied for wastewater disposal at El-Dair.

Cd Cu Zn Pb Cr Ni Co Mn Fe% Depth (cm)

0.97 93 462 81 135 40 22 1121 3.45 00-20 1.15 43 235 45 176 37 26 1065 4.04 20-40

Mean

0.95 61 266 64 139 39 20 884 3.59 00-20 1.06 42 179 37 162 38 27 1074 3.87 20-40

Median

0.51 25 143 26 85 28 13 583 2.26 00-20 0.54 17 120 21 65 20 20 482 1.15 20-40

Minimum

1.50 224 1429 186 179 59 27 4213 4.69 00-20 2.11 63 486 111 415 49 31 1421 6.69 20-40

Maximum

0.25 61 347 54 30 8 5 873 0.78 00-20 0.42 13 114 25 85 8 3 274 1.50 20-40

sd.

0.78 46 219 41 106 35 18 732 2.55 00-20 0.87 33 154 29 126 30 23 839 3.37 20-40

25% percentile

1.12 118 559 118 157 42 26 1099 3.98 00-20 1.33 53 278 57 185 41 28 1301 4.79 20-40

Farm

land

s (n=

30)

75% percentile

1.04 83 427 104 141 43 24 1171 4.37 Mean 1.02 65 319 61 141 41 22 855 3.35 Median 0.85 32 165 23 94 25 15 557 1.35 Minimum 1.40 223 1040 306 222 67 39 2434 13.88 Maximum 0.16 54 286 98 36 14 8 615 3.28 sd. 0.87 44 211 26 112 29 18 758 2.06 25% percentile 1.15 88 483 168 153 56 25 1389 6.04

Surf

ace

laye

r

Was

tew

ater

po

nds (

n=15

)

75% percentile

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Fe

(%)

0

3

6

9

12

15

1 2 3 4 5 6 7

MaxMin75%25%Median

1- Cultivated floodplain (topsoil)2- Cultivated floodplain (subsoil)3- Reclaimed lands (topsoil)4- Reclaimed lands (subsoil)5- Wadi deposits6- Wastewater disposal site at El-Kol7- Wastewater disposal site at El-Dai


(25%) and upper quartile (75%) of iron content (%) in the studied sediments.

4

6

8

10

12

14

%

26 3

2 00

N26

28

00 N

26 3

2 00

N26

28

00 N

31 32 00 E 31 36 00 E 31 40 00 E 31 44 00 E 31 48 00 E 31 52 00 E



Kilometers02.5 55

31 32 00 E 31 36 00 E 31 40 00 E 31 44 00 E 31 52 00 E31 48 00 E

Fig. (24): Geochemical contour map showing distribution of the total iron content in the

surficial sediments (<63 µm) throughout the study area.

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M

n (p

pm)

200

400

600

800

1000

2000

4000

6000

1 2 3 4 5 6 7

Fig. (25): A box-whisker graph showing the minimum, maximum, median, lower quartile (25%) and upper quartile (75%) of manganese content (ppm) in the studied sediments. See figure (23) for explanation.

800

1800

2800

3800

4800

ppm

26 3

2 00

N26

28

00 N

26 3

2 00

N26

28

00 N

31 32 00 E 31 36 00 E 31 40 00 E 31 44 00 E 31 48 00 E 31 52 00 E



Kilometers02.5 55

31 32 00 E 31 36 00 E 31 40 00 E 31 44 00 E 31 52 00 E31 48 00 E

Fig. (26): Geochemical contour map showing distribution of the total manganese content in

the surficial sediments (<63 µm) throughout the study area.

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C

o (p

pm)

10

20

30

40

50

60

1 2 3 4 5 6 7

Fig. (27): A box-whisker graph showing the minimum, maximum, median, lower quartile (25%) and upper quartile (75%) of cobalt content (ppm) in the studied sediments. See figure (23) for explanation.

15

25

35

45

ppm

26 3

2 00

N26

28

00 N

26 3

2 00

N26

28

00 N

31 32 00 E 31 36 00 E 31 40 00 E 31 44 00 E 31 48 00 E 31 52 00 E



Kilometers02.5 55

31 32 00 E 31 36 00 E 31 40 00 E 31 44 00 E 31 52 00 E31 48 00 E

Fig. (28): Geochemical contour map showing distribution of the total cobalt content in the


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N

i (pp

m)

20

40

60

80

100

1 2 3 4 5 6 7

Fig. (29): A box-whisker graph showing the minimum, maximum, median, lower quartile (25%) and upper quartile (75%) of nickel content (ppm) in the studied sediments. See figure (23) for explanation.

40

60

80

100

120

ppm

26 3

2 00

N26

28

00 N

26 3

2 00

N26

28

00 N

31 32 00 E 31 36 00 E 31 40 00 E 31 44 00 E 31 48 00 E 31 52 00 E



Kilometers02.5 55

31 32 00 E 31 36 00 E 31 40 00 E 31 44 00 E 31 52 00 E31 48 00 E

Fig. (30): Geochemical contour map showing distribution of the total nickel content in the


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C

r (pp

m)

50

60

70

8090

100

200

300

400

1 2 3 4 5 6 7

Fig. (31): A box-whisker graph showing the minimum, maximum, median, lower quartile (25%) and upper quartile (75%) of chromium content (ppm) in the studied sediments. See figure (23) for explanation.

100

140

180

220

260

300

ppm

26 3

2 00

N26

28

00 N

26 3

2 00

N26

28

00 N

31 32 00 E 31 36 00 E 31 40 00 E 31 44 00 E 31 48 00 E 31 52 00 E



Kilometers02.5 55

31 32 00 E 31 36 00 E 31 40 00 E 31 44 00 E 31 52 00 E31 48 00 E

Fig. (32): Geochemical contour map showing distribution of the total chromium content in


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Pb

(ppm

)

10

20

40

60

80

100

200

1 2 3 4 5 6 7

Fig. (33): A box-whisker graph showing the minimum, maximum, median, lower quartile (25%) and upper quartile (75%) of lead content (ppm) in the studied sediments. See figure (23) for explanation.

20

50

80

110

140

170

200

230

260

290

ppm

26 3

2 00

N26

28

00 N

26 3

2 00

N26

28

00 N

31 32 00 E 31 36 00 E 31 40 00 E 31 44 00 E 31 48 00 E 31 52 00 E



Kilometers02.5 55

31 32 00 E 31 36 00 E 31 40 00 E 31 44 00 E 31 52 00 E31 48 00 E

Fig. (34): Geochemical contour map showing distribution of the total lead content in the


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Zn

(ppm

)

50

75

100

250

500

750

1000

1 2 3 4 5 6 7

Fig. (35): A box-whisker graph showing the minimum, maximum, median, lower quartile (25%) and upper quartile (75%) of zinc content (ppm) in the studied sediments. See figure (23) for explanation.

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

ppm

26 3

2 00

N26

28

00 N

26 3

2 00

N26

28

00 N

31 32 00 E 31 36 00 E 31 40 00 E 31 44 00 E 31 48 00 E 31 52 00 E



Kilometers02.5 55

31 32 00 E 31 36 00 E 31 40 00 E 31 44 00 E 31 52 00 E31 48 00 E

Fig. (36): Geochemical contour map showing distribution of the total zinc content in the


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C

u (p

pm)

10

20

40

60

80

100

200

400

1 2 3 4 5 6 7

Fig. (37): A box-whisker graph showing the minimum, maximum, median, lower quartile (25%) and upper quartile (75%) of copper content (ppm) in the studied sediments. See figure (23) for explanation.

50

100

150

200

250

300

ppm

26 3

2 00

N26

28

00 N

26 3

2 00

N26

28

00 N

31 32 00 E 31 36 00 E 31 40 00 E 31 44 00 E 31 48 00 E 31 52 00 E



Kilometers02.5 55

31 32 00 E 31 36 00 E 31 40 00 E 31 44 00 E 31 52 00 E31 48 00 E

Fig. (38): Geochemical contour map showing distribution of the total copper content in the


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C

d (p

pm)

0.5

1.0

1.5

2.0

2.5

1 2 3 4 5 6 7

Fig. (39): A box-whisker graph showing the minimum, maximum, median, lower quartile (25%) and upper quartile (75%) of cadmium content (ppm) in the studied sediments. See figure (23) for explanation.

0.7

0.9

1.1

1.3

1.5

1.7

1.9

ppm

26 3

2 00

N26

28

00 N

26 3

2 00

N26

28

00 N

31 32 00 E 31 36 00 E 31 40 00 E 31 44 00 E 31 48 00 E 31 52 00 E



Kilometers02.5 55

31 32 00 E 31 36 00 E 31 40 00 E 31 44 00 E 31 52 00 E31 48 00 E

Fig. (40): Geochemical contour map showing distribution of the total cadmium content in


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5.1.3 Statistical examination 5.1.3.1 Correlation coefficient

In order to quantify the inter-variable relationship among the studied sediments throughout the whole study area, the correlation coefficient was calculated for the estimated heavy metals (Fe, Co, Ni, Mn, Cr, Cu, Pb, Zn and Cd), carbonate, organic matter and clay content. The calculated correlation coefficients are given in table (15) and the interrelation between heavy metals and the main soil properties is displayed in figure (41). Table (15): Correlation coefficients of heavy metals, carbonate (CaCOB3B), organic matter

(OM) and clay content in the investigated sediments (n= 226).

Clay CaCOB3B OM Ni Fe Mn Zn Co Cd Pb Cu Cr Clay 1.00 CaCOB3B

-0.56P

*P 1.00

OM -0.21P

*P 0.02 1.00

Ni 0.43P

*P -0.53P

*P -0.12P

*P 1.00

Fe 0.60P

*P -0.72P

*P -0.29P

*P 0.64P

*P 1.00

Mn 0.24P

*P -0.36P

*P 0.09 0.27P

*P 0.25P

*P 1.00

Zn -0.22P

*P 0.01 0.64P

*P 0.05 -0.20P

*P 0.03 1.00

Co 0.51P

*P -0.53P

*P -0.51P

*P 0.64P

*P 0.72P

*P 0.27P

*P -0.43P

*P 1.00

Cd -0.48P

*P 0.88P

*P -0.10 -0.40P

*P -0.62P

*P -0.30P

*P -0.03 -0.34P

*P 1.00

Pb -0.23P

*P 0.14P

*P 0.76P

*P -0.01 -0.25P

*P 0.09 0.60P

*P -0.46P

*P 0.03 1.00

Cu 0.02 -0.12P

*P 0.41P

*P 0.51P

*P 0.10 0.01 0.70P

*P -0.04 -0.06 0.50P

*P 1.00

Cr 0.04 -0.35P

*P -0.03 0.35P

*P 0.36P

*P 0.08 0.06 0.32P

*P -0.31P

*P 0.12P

*P 0.23P

*P 1.00

* significant at P<0.05 Lead and zinc are positively correlated (r= 0.60) and they are positively

correlated with the organic matter content (r= 0.76 and 0.64, respectively). On the other hand, they are negatively correlated with the clay content (r= -0.23 and -0.22, respectively), insignificant or less significant correlation was found with the carbonate content (r= 0.14 and 0.01, respectively). So, lead and zinc are significantly associated in sediments rich in organic matter but they are diluted in the clay-rich sediments; they display no important effect following the distribution manner of the carbonate content.

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Fig. (41): Scatter plot diagram showing the interrelation between the total heavy metals

content and the main properties of the studied sediments (clay, CaCOB3B and organic matter).

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Cadmium is very strongly correlated with carbonate (r=0.88), whereas it is

negatively correlated with all other variables. This indicates that carbonate is the main variable controlling the behavior of cadmium. Consequently, the cadmium content follows the distribution pattern of the carbonate fraction in the investigated sediments.

Iron, cobalt and nickel, and to a less extent manganese, are significantly

correlated and they are positively correlated with the clay fraction (r=0.60, 0.51, 0.43 and 0.24, respectively), while they are negatively correlated with the carbonate content (r=-0.72, -0.53, -0.53 and -0.36, respectively). This implies that iron, cobalt, nickel and manganese are concentrated principally in the non-calcareous fine siliciclastics, whereas they are diluted in the carbonate-rich sediments. Cobalt, iron and nickel are negatively correlated with the organic matter content (r=-0.51, -0.29 and –0.12, respectively); so, organic matter is another factor, controlling the behavior of cobalt, iron and nickel reversely in the studied sediments. Although, chromium displays indiscernible correlation with the clay content (r=0.04), it is positively correlated with iron, nickel and cobalt (r=0.36, 0.35 and 0.32, respectively) whereas it is negatively correlated with the carbonate content, suggesting its co-association with iron, nickel and cobalt in the non-calcareous fraction.

5.1.3.2 The anomalous metal levels: (outliers and extremes)

The non-anomalous values of a variable are those concentrated around the middle of the distribution and they are statistically referred to as the non-outlier values. The non-outlier range includes the values of variable that fall between statistically determined lower and upper outlier limits. On the other hand, the anomalous values of a distribution are considerably shifted far from the central point and they are referred to as the outlier and extreme values.

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Values of the variable comparatively shifted from the middle of the distribution are deemed to be “outliers” and they are characterized by the following conditions:

Value > UBV + 1.5 (UBV + LBV)

Or Value < UBV - 1.5 (UBV – LBV) Where, UBV is the Upper Background Value and it is equal to either the

mean plus the standard error or the upper quartile (75P

thP percentile). LBV is the

Lower Background Value and it corresponds to either the mean minus the standard error or the lower quartile (25P

thP percentile).

The values, which are extremely displaced from the midpoint, are regarded

to be “extremes” and they follow the following circumstances:

Value > UBV + 3 (UBV + LBV) Or Value < UBV - 3 (UBV – LBV)

A general classic box-whisker plot illustrating the ranges of outliers and

extremes in accordance with the stated conditions is displayed in figure (42). However, in order to quantify the distribution pattern and behavior of

heavy metals in the studied sediments and discuss their controlling factors, the anomalous levels and their spatial variability should be determined. Therefore, the anomalous values (outliers and extremes) of the various heavy metals were estimated by means of the STATISTICA computer program considering the following conditions:

Extremes > UBV + 3(UBV – LBV) > outliers > UBV + 1.5 (UBV – LBV)

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Fig. (42): A general classic box-whisker plot showing the conditions

of the non-outlier range and the outlier and extreme levels.

The Upper Background Value (UBV) is considered here to represent the

upper quartile (75P

thP percentile), whereas the lower quartile (25P

thP percentile)

signifies the Lower Background Value (LBV). A box-whisker graph demonstrating the median, lower and upper quartiles, non-outlier limits and outlier and extreme values is shown in figure (43). The outlier and extreme values of heavy metals reported in the examined sediments throughout the study area are given in table (16). It is obvious that lead, zinc and copper display the most frequent anomaly (36, 26 and 16 samples, respectively) and most of the anomalous levels are found in the lands applied for wastewater disposal at El-Kola and El-Dair sites. This implies that the wastewater disposal plays an important role in accumulating these metals in soils of the considered sites.

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Fig. (43): Box-whisker graph of the total heavy metals (ppm) showing the median, lower and

upper quartiles, non-outlier range and outlier and extreme values

Chromium, cadmium, manganese and nickel display less frequent

anomaly (9, 9, 7 and 4 samples, respectively) and the anomalous values are irregularly distributed throughout the different landuses. This suggests that the influence of anthropogenic activities on the behavior of these metals is limited. Iron displays abnormal levels at only two sites that show no anomaly for lead, zinc or copper. This suggests that such elevated levels of iron are either naturally occurring following abnormal accumulation of iron-rich phases or due to independent addition related to unknown practice. No anomalous levels of cobalt were recorded throughout the study area, reflecting its natural behavior and suggesting no anthropogenic accumulation in the examined sediments.

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Table (16): The anomalous levels of heavy metals (outliers* and extremes**) in the studied sediments.

SN ID Landuse Fe% Mn Ni Cr Pb Zn Cu Cd 1 22 Topsoil 2193* 2 32 Topsoil 119* 3 115 Topsoil 52* 1249** 244** 4 115

Cultivated floodplain

Subsoil 469* 5 4 Subsoil 1.80* 6 8 Topsoil 12.3* 243* 7 54 Subsoil 2.00* 8 69 Subsoil 1.88* 9 71 Topsoil 401* 10 124 Topsoil 3205** 248** 11 124 Subsoil 148** 12 153

Reclaimed lands

Subsoil 2.05* 13 9 280* 14 61

Wadi deposits

Surface layer 253*

15 35 1.90* 16 36 2.00* 17 38 185** 18 41A 49* 180** 19 41B 55* 20 42 645** 21 43 239* 22 44 125* 23 46 2368* 24 47 296* 25 48 256* 26 80 5418** 1.85* 27 140 108* 171** 659** 267** 28 141 123* 244* 176** 717** 338** 29 142 109* 154** 794** 211** 30 143 148** 628** 206** 31 144 165** 531** 173** 32 145 157** 598** 180** 33 146

Lan

ds a

pplie

d fo

r w

aste

wat

er d

ispo

sal a

t El-K

ola

Surf

ace

laye

r

59* 34 94 Topsoil 66** 776** 150* 35 94 Subsoil 415** 379* 36 96 Topsoil 93** 37 96 Subsoil 1.91* 38 97 Topsoil 51* 514** 39 128 Subsoil 82** 40 129 Topsoil 146** 568** 41 129 Subsoil 57* 42 130 Topsoil 52* 43 130 Subsoil 56* 2.11* 44 131 Topsoil 4213** 186** 1429** 224** 45 131 Subsoil 300* 58* 486** 46 134 Topsoil 64** 438* 47 135 Topsoil 173** 550** 48 135 Subsoil 111** 49 136 Topsoil 68** 50 138 Topsoil 143** 868** 206** 51 138

Farm

land

s

Subsoil 433* 52 91 390* 53 92 61* 430* 135* 54 93 263** 55 100 13.9* 56 119 62* 885** 57 120 2434* 58 121 67** 59 122 2425* 306** 60 123 131** 61 126 61* 536** 62 139 205** 900** 175** 63 155

Land

s app

lied

for

was

tew

ater

disp

osal

at E

l-Dai

r

Was

tew

ater

pon

ds

Surf

ace

laye

r

236** 1040** 223**

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5.1.3.3 Principal Component Analysis (PCA)

The multivariate data analysis is a powerful statistical technique being able to consider numerous properties and inter-relations simultaneously. Multivariate statistical methods are capable to reduce the multiple variables or measurements into easily interpretable statistical parameters; objective classification and discrimination of samples or observations can be also achieved. Multivariate statistical analysis is frequently utilized in solving the different geological and geochemical problems (e.g. Stattegger, 1987; Roser and Korsch, 1988; Mezzadri and Saccani, 1989; De Visser, 1991; Molinaroli et al., 1991; Bellon et al., 1994; Omer, 1996; Danielsson et al., 1999; Omer, 2003a; Omer and Hassan, 2004; Ibrahim and Omer, 2004). However, numerous statistical techniques of the multivariate data analysis are available. Among those, the multiple linear regression, principal component analysis, factor analysis; discriminant function analysis and cluster analysis are the most common ones (Davis, 1973, 1986; Joreskog et al., 1976; Le Maitre, 1982; Massart and Kaufman, 1983).

The principal component analysis (PCA) is a forceful statistical method to

extract the complicated variations into limited comprehensive data sets. The PCA is used to reduce the set into few components capable to explain the major variation within the data. Each component is a weighted linear combination of the original variables. Using the PCA, the most important variables can be determined and classified into different combinations depending upon their relative similarities (R-mode). Also, samples of a given distribution can be separated into distinctive groups and their inter-relations can be discussed and interpreted (Q-mode). The PCA has been frequently employed in environmental geochemistry to determine the baseline values of metals in sediments and soils. Numerous studies have used the PCA to differentiate heavy metals in sediments and soils into various associations according to the similarity in their behavior. So, metals of natural geogenic source could be strictly separated from those of anthropogenic supply (Geladi and Kowalski, 1986; Aragnَ et al., 2000; Li et al., 2000; Facchinelli et al., 2001; Omer, 2003a).

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In the present study, the PCA was performed to monitor the inter-variable (R-mode) and inter-sample (Q-mode) relationships throughout the investigated sediments. Values of the organic matter, carbonate and clay fraction together with the heavy metals content (Fe, Mn, Ni, Co, Pb, Zn, Cd, Cu, Cr) are the considered variables.

5.1.3.3.1 Metal association and sources (R-mode PCA)

The R-mode PCA was achieved to estimate the metal associations and discuss their possible sources. The various parameters of the PCA (eigenvalues, eigenvectors and PCA loadings) were calculated. The resulted eigenvalues, variance percentages and cumulative variance percentages are given in table (17). Values of the different eigenvalues are displayed in figure (44). It is clear that the first two eigenvalues are the most powerful and distinctive ones. They collectively account for about 62% of the total variance in the data set. In order to make the components more interpretable, while still being orthogonal, an Equimax rotation was used.

Table (17): Eigenvalues, total variance and cumulative variance percentage extracted from the data set.

No. of eigenvalues Eigenvalue Variance% Cumulative

Variance%1 4.4059 36.72 36.72 2 2.9948 24.96 61.67 3 1.2034 10.03 71.70 4 0.8996 7.50 79.20 5 0.8269 6.89 86.09 6 0.4881 4.07 90.16 7 0.3656 3.05 93.20 8 0.2457 2.05 95.25 9 0.2163 1.80 97.05

10 0.1449 1.21 98.26 11 0.1248 1.04 99.30 12 0.0839 0.70 100.00

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Number of Eigenvalues

Val

ue

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

1 2 3 4 5 6 7 8 9 10 11 12

Fig.(44): Values of the different eigenvalues showing that the 1P

stP and 2P

ndP components are the

most effective ones.

The calculated eigenvectors on the first two factors are shown in table (18).

The bivariate scatter plot diagram displaying the loadings of the first and second principal components is shown in figure (45). It is obvious that four different trends of variable associations can be strictly distinguished implying a common source or behavior:

clay trend (geogenic) carbonate trend (geogenic) organic matter trend (anthropogenic) mixed trend

Clay, iron and cobalt are tightly associated forming a pronounced trend (the

clay trend). These variables are positively loaded on the 1P

stP principal component

whereas they are negatively loaded on the 2P

ndP one. Metals loaded on this trend

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(iron and cobalt) display no anomalous levels in most samples; all cobalt values lie within the non-outlier range and only two samples exhibit outlier values for iron. This association is most probably of natural geogenic source (i.e. they are lithogenically controlled) and it corresponds to uncontaminated clay-rich sediments. Therefore, the iron and cobalt contents are deemed to be predominantly of lithogenic origin throughout the study area, where no significant anthropogenic supply is suggested. The strong positive correlation of iron and cobalt (r=0.72) and their significant correlation with the clay content (r=0.60 and 0.51, respectively) confirm their tight co-association and support the stated suggestion.

The most interesting association is the carbonate trend including carbonate

and cadmium which are negatively loaded on both the 1P

stP and 2P

ndP components.

This trend is restricted to carbonate-rich sediments and suggests that carbonate is the most important form of cadmium in the investigated sediments. The pervasive association of cadmium and carbonate is confirmed by their very strong correlation (r=0.88). This assemblage is most probably of natural geogenic sense and it follows the distribution pattern of the carbonate fraction.

Table (18): Loadings of the PCA eigenvectors for the first two components

Association Variable Component 1 Component 2 Clay 0.6784 -0.2138 Fe 0.8771 -0.1788 Clay trend

(geogenic) Co 0.7511 -0.4431

CaCOB3B -0.8775 -0.0421 Carbonate trend (geogenic) Cd -0.7670 -0.1191

OM -0.1595 0.8387 Pb -0.1492 0.8506 OM trend

(anthropogenic) Zn -0.0690 0.8734 Cu 0.2562 0.7534 Cr 0.4672 0.1821 Mn 0.4235 0.1169

Mixed trend

Ni 0.7866 0.1373

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The organic matter trend includes the organic matter, lead and zinc. These variables are negatively loaded on the 1P

stP principal component whereas

they are positively loaded on the 2P

ndP one. This association is severely shifted

away from the mentioned geogenic trends. The anomalous contents (outlier and extreme) of lead and zinc frequently recorded in the considered sediments (36 and 26 samples, respectively) can only be interpreted as they are of anthropogenic supply. The severe association of lead and zinc with the organic matter and their reverse behavior relative to those of natural geogenic source suggest that they are almost certainly of anthropogenic contribution. The significant interrelation between lead and zinc (r=0.60) and their strong correlation with the organic matter content (r=0.76 and 0.64, respectively) is another clue documenting their genetic relation.

Fig. (45): Loadings of the 1P

stP and 2P

ndP R-mode principal components (Equamax raw rotation)

for the heavy metals, clay, carbonate (CaCOB3B) and organic matter (OM) contents through the studied sediments.

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On the other hand, manganese, nickel, chromium and copper are

positively loaded on both the 1 P

stP and 2 P

ndP principal components forming one

related association. This trend is intermediate between the clay trend and

organic matter trend indicating that the behavior of these metals is affected

by both the geogenic characteristics of sediments and the anthropogenic

supply; therefore, it was termed as mixed trend. Chromium, manganese and

nickel are closely shifted toward the clay trend implying that their behavior

is significantly affected by the lithologic characteristics of sediments

whereas the anthropogenic supply is effective only in some sites.

The less frequent anomalous contents of these metals support their limited

contribution by anthropogenic practice. Contrarily, the reverse is true for

copper, where it is significantly shifted toward the organic matter trend

suggesting its significant influence by the anthropogenic supply.

The frequently recorded anomalous levels of copper (16 samples) and its

positive correlation with the organic matter (r=0.41) confirm such

anthropogenic effect.

5.1.3.3.2 Inter-sample relationship (Q-mode PCA)

Aiming to classify the examined sediments into interpretable

associations reflecting their similarity and dissimilarity in behavior, the

Q-mode PCA was carried out. It is apparent from table (18) that the

1 P

stP principal component is positively controlled by clay, iron, cobalt,

copper, chromium, manganese and nickel whereas it is negatively

contributed by carbonate, cadmium, organic matter, lead and zinc.

On the other hand, the 2 P

ndP principal component is negatively influenced by

clay, iron, cobalt, carbonate and cadmium, while it is positively loaded by

organic matter, lead, zinc, copper, chromium, manganese and nickel.

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The calculated PCA scores of the first two factors are tabulated in

Appendix (E) and are displayed in figure (46). It is obvious that plots of

the different samples are meaningfully distributed throughout the PCA

graph following the distribution pattern of the variable associations

(clay, organic matter, carbonate and mixed trends).

Almost all samples of the cultivated floodplain (69 of 70 samples) are

loaded on the clay trend. This indicates that the compositional

characteristics of these sediments are naturally controlled following the

parent source rock composition in the upper reaches of the Nile

particularly the Ethiopian basaltic plateau. On the other hand, contribution

of heavy metals from anthropogenic practice was occasional.

Only one sample (No. 115) displayed anomalous levels of zinc, copper and

lead indicating local contamination of this site, which has special situation

as stated above.

Most samples of the topsoil layer of the reclaimed lands (24 of 33

samples) are contained in the clay trend following sediments of the

cultivated floodplain from which they were transported. Seven samples are

loaded on the carbonate trend reflecting the effect of inter-mixing with the

underlying calcareous subsoil layer. Only two samples follow the organic

matter trend reflecting the anthropogenic effect related to local wastewater

disposal. So, chemical composition of the topsoil layer of the reclaimed

lands is naturally controlled by the sediment lithology whereas the impact

of anthropogenic practice is occasional. Most samples of the subsoil layer

(24 of 33 samples) are included in the carbonate trend reflecting their

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Fig.

(46)

: Loa

ding

s of

the

1PstP a

nd 2

PndP Q

-mod

e pr

inci

pal c

ompo

nent

s (E

quam

ax r

otat

ion)

for

the

stud

ied

sedi

men

ts. H

eavy

m

etal

s, cl

ay, c

arbo

nate

and

org

anic

mat

ter

are

the

cons

ider

ed v

aria

bles

.

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calcareous nature. Eight samples are loaded on the clay trend reflecting the

downward migration of the fine clay particles from the overlying topsoil

layer. All the examined samples of wadi deposits (17 samples) are loaded on the

carbonate trend following their calcareous nature where they are formed principally of the disintegrated products from the nearby Eocene limestone plateau. So, the compositional characteristics of wadi deposits are naturally controlled and no anthropogenic effect is observed.

The majority of samples from the wastewater disposal site at El-Dair

(50 of 55 samples) are distributed between the organic matter trend and the calcareous trend. This indicates that these samples are influenced by two main factors: the natural calcareous composition and the addition of biosolids related to the raw wastewater disposal.

Sediments of the wastewater disposal site at El-Kola are extremely

scattered throughout the different variable trends. Ten samples are loaded on the carbonate trend, 9 samples on the clay trend, 6 samples on the mixed trend and 4 samples on the organic matter trend. Such diverse compositional behavior of these sediments is attributed to both natural lithological characteristics and anthropogenic impact related to raw wastewater disposal. Moreover, the lithological characteristics of these sediments are complicated, where they are formed from a variable mixture (calcareous and siliciclastic) derived from the nearby Eocene limestone and Pliocene clay.

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5.2 Metal Bioavailability

Metal bioavailability means its availability to be taken into the

biosystem (Linz and Nakles, 1997; NRC, 2003). The mobility and

bioavailability of heavy metal in sediments and soil depends chiefly on its

mode of occurrence. The soluble and exchangeable species are the readily

bioavailable chemical forms. It is important to evaluate the availability and

mobility of heavy metals to establish environmental guidelines for their

potential toxic hazards, and to understand the chemical behavior and fate

of heavy metal contaminants in polluted sediments and soil (Davies, 1980).

Numerous extraction procedures are used for determining the concentration

of readily bioavailable metal content in sediments and soils

(e.g. Lindsay and Norvell, 1978; Tessier, et al., 1979; Lake et al., 1984;

Ure et al., 1993). Of these, the protocol of Lindsay and Norvell (1978),

which was used in the present study, is widely used. The bioavailable

levels of the mentioned metals were measured in the DTPA

(Diethylenetriaminepentaacetic-acid) + TEA (Triethanolamine) extraction.

5.2.1 Metal distribution and variability

In the present study, the bioavailable content of heavy metals was estimated

in the bulk sediment samples (<2mm) for the surficial layer throughout the study

area. Data of the estimated bioavailable heavy metals through the studied

sediments are given in Appendix (F). The main descriptive statistics of the

estimated heavy metals throughout the studied landuses are shown in tables

(19-23). Distribution and variability of the bioavailable fraction of the studied

heavy metals through the study area will be discussed in the following

paragraphs.

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5.2.1.1 Iron (Fe)

Regarding the available iron in normal alluvial soils of Upper Egypt, Abd El-Razik et al. (1984a) reported that DTPA-extractable iron ranged from 0.35 to 26.6 ppm with an average of 8.0 ppm. El-Sokkary and Lag (1979) found that the available concentration of iron in the soils of Egypt ranged between 6.0 and 9.5 ppm.

In the current study, the minimum, maximum, median, lower quartile

(25%) and upper quartile (75%) of the bioavailable iron content are shown in the box-whisker graph given in figure (47). The spatial distribution pattern of the bioavailable iron is displayed in a geochemical map and given in figure (48).

Regarding the cultivated floodplain (Table 19), the bioavailable iron content ranges from 3.2 to 32.3 ppm (mean=19.8, median=19.6 ppm, sd.=6.1). Abd El-Razek et al. (1984a) found that the DTPA-extractable iron ranges from 2.83 to 19.9 ppm in the soils of Sohag. Although the elevated level of the total iron content in sediments of the floodplain, the bioavailable fraction is relatively low. This indicates that the major part of iron is firmly incorporated in the crystal lattice of iron-bearing mineral phases (e.g. ferromagnesian minerals and iron oxides).

The estimated concentrations of bioavailable iron in the reclaimed lands (Table 20) range from 5.4 to 463.8 ppm (mean=37.9, median=18.5 ppm, sd.=82.9). Generally, the bioavailable iron content, in median values, is close to that of the cultivated floodplain. The elevated mean value, which is twice higher than the median, reflects the presence of abnormally elevated values of the bioavailable iron in some sites. Extremely elevated level of bioavailable iron was found in sites Nos. 71 and 124 (197.5 and 463.8 ppm, respectively). As stated above, site No.71 is frequently used for manual wastewater disposal, while site No.124 is situated immediately close to the wastewater disposal site at El-Dair and located in lands oftenly irrigated with wastewater. So, the elevated bioavailable fraction of iron is evidently related to the wastewater disposal

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practice. Rabie et al. (1996) reported that available iron increased very much especially in the surface layer (66.2-75.1 ppm) due to irrigation with liquid wastes. El-Nashar (1985) found that available iron increased 17 folds due to irrigation with sewage effluents.

Levels of the bioavailable iron in the wadi deposits of the study area (Table 21) range from 5.4 to 15.7 ppm (mean=9.3, median=9.0 ppm, sd.=2.8). Wadi deposits exhibit significantly lower iron content than the cultivated floodplain (p<0.001). Thie matter may be controlled by the carbonate immobilization. Pathak et al. (1979) obtained various ranges for available iron in soils 0.35 to 18.4 ppm.

With respect to the distribution manner of bioavailable iron in the lands applied for wastewater disposal at El-Kola (Table 22), it ranges from 3.5 to 526.0 ppm with a mean value of 120.8 ppm (median=41.4 ppm, sd.=162.6). The high value of standard deviation reflects the very wide range and the extreme variability of iron bioavailability in these sediments. The average content of bioavailable iron in these sediments is considerably higher than its level in sediments of the cultivated floodplain (p<0.001) and the nearby wadi deposits (p=0.007). The stated behavior of bioavailable iron reveals that it is significantly and positively affected by the wastewater disposal practice in this site.

Regarding the distribution pattern of bioavailable iron in the lands applied for

wastewater disposal at El-Dair (Table 23), it varies between 25.4 and 878.3 ppm (mean=334.3, median=283.9 ppm, sd.=287.6) in the wastewater farmlands. The estimated bioavailable iron content, in average, is markedly higher than that reported for the cultivated floodplain (p<0.001) and wadi deposits (p<0.001).

The bioavailable iron content measured in the surficial sediments of the

wastewater ponds at El-Dair (Table 23) displays a wide range varying from 99.9 to 918.3 ppm (mean=333.4, median=261.2 ppm) as indicated from the higher value of standard deviation (sd.=249.4). The average content of

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bioavailable iron in these sediments is significantly higher than that of the adjacent wadi deposits whereas it is very close to that of the wastewater farmlands (p=0.992).

The abnormally elevated content of bioavailable iron in the lands applied

for wastewater disposal at El-Kola and El-Dair indicates that a considerable content of the mobile iron is carried by the wastewater; corrosion of the household and transporting iron pipes may be the main source. The wide range of the bioavailable iron content in these sites reflects the variable grade of contamination by the disposed wastewater.

5.2.1.2 Manganese (Mn)

Regarding the available manganese, Sedberry et al. (1978) reported that the concentration of DTPA- extractable fraction in Luisiana soils was in the range of 0.2 to 103 ppm. Taha (1980) found that the available manganese ranged between 5.5 and 25.5 ppm in the Egyptian alluvial soils. Abou El-Khir (2000) stated that the available manganese ranged between 6 to 20 ppm in some Delta soils. Ghoneim et al. (1979) found that the DTPA-extractable manganese in some alluvial and sandy calcareous soils of Assiut ranged from 10.3 to 345 ppm. Kishk et al. (1980) reported values from 1.1 to 57.4 ppm for available manganese in soils of Middle and Upper Egypt. In a study through Assiut, Sohag and Qena, Abd el-Razek et al. (1984b) found that the DTPA-extractable manganese ranged from 0.47 to 53.6 ppm.

Assuming the present study, the minimum, maximum, median, lower

quartile (25%) and upper quartile (75%) of bioavailable manganese content through the studied sediments are given in the box-whisker graph shown in figure (49). A geochemical contour map showing the spatial distribution pattern of bioavailable manganese through the study area is displayed in figure (50).

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Regarding the cultivated floodplain (Table 19), the bioavailable manganese content ranges from 17.9 to 142.3 ppm (mean=67.0, median=56.0 ppm, sd.=35.5). Although the total manganese content in sediments of the floodplain is extremely lower than that of iron, its bioavailable fraction is considerably higher; this reflects the more mobility of manganese under the surficial conditions.

The estimated concentrations of bioavailable manganese in the reclaimed

lands (Table 20) range from 4.3 to 269.0 ppm (mean=64.9, median=53.3 ppm, sd.=54.1). Generally, the bioavailable manganese content of this landuse, in average, is very close to that reported for the cultivated floodplain (p=0.851).

Levels of the bioavailable manganese in the wadi deposits of the study area

(Table 21) ranges from 1.66 to 144.7 (mean=20.5, median=5.9 ppm, sd.=34.3). Wadi deposits exhibit significantly lower manganese content than the cultivated floodplain (p<0.001) reflecting the effect of carbonate immobilization.

Concerning the bioavailable manganese concentration in the lands applied

for wastewater disposal at El-Kola (Table 22), it varies from 0.56 to 184.8 ppm (mean=41.2, median=29.4, sd.=38.6). The average content of the bioavailable manganese in these sediments is relatively lower than its level in sediments of the Nile floodplain (p=0.007), but there is no significant difference with its content in the wadi deposits (p=0.074).

The bioavailable manganese content estimated in the wastewater farmlands

at El-Dair (Table 23) fluctuates between 9.9 and 67.2 ppm (mean=38.8, median=42.1 ppm, sd.=17.1). The bioavailable manganese content, on the average, is relatively lower than that reported for the cultivated floodplain (p=0.005), whereas there is insignificant difference compared with that of the nearby wadi deposits (p=0.072).

The bioavailable manganese level estimated in sediments of the wastewater

ponds at El-Dair (Table 23) ranges between 12.1 and 89.7 ppm (mean=40.3,

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median=30.4 ppm, sd.=25.5). The average manganese content in these sediments is extremely similar to that of lands applied for wastewater disposal at El-Kola (p=0.933) and El-Dair farmlands (p=0.854).

The distribution pattern of the bioavailable manganese content in the lands

applied for wastewater disposal at El-Kola and El-Dair is markedly similar to that of the nearby wadi deposits. This matter indicates that the wastewater disposal practice has no marked effect on the manganese bioavailability.

5.2.1.3 Cobalt (Co)

The box-whisker given in figure (51) shows the minimum, maximum, median, lower quartile (25%) and upper quartile (75%) of bioavailable cobalt content through the investigated landuses considered in the present study. The spatial distribution pattern of bioavailable cobalt content throughout the study area is shown in the geochemical contour map displayed in figure (52).

Regarding the cultivated floodplain (Table 19), the bioavailable cobalt

content ranges from 0.34 to 2.22 (mean=0.96, median=0.76 ppm, sd.=0.55). So, the major part of cobalt is unavailable being incorporated in the crystal lattice of its bearing mineral phases particularly the ferromagnesian minerals.

The estimated concentrations of bioavailable cobalt in the reclaimed lands

(Table 20) range from 0.12 to 3.06 ppm (mean=0.88, median=0.64 ppm, sd.=0.60). Generally, the bioavailable cobalt content, in average, is very close to that of the cultivated floodplain (p=0.564).

Levels of the bioavailable cobalt in the wadi deposits (Table 21) of the

study area range from 0.22 to 2.44 ppm (mean=0.70, median=0.48 ppm, sd.=0.65). Wadi deposits exhibit no significant difference in the bioavailable cobalt content compared with that of the cultivated floodplain (p=0.137).

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With respect to the distribution manner of bioavailable cobalt in the lands applied for wastewater disposal at El-Kola (Table 22), it ranges from 0.13 to 1.62 ppm, with a mean value of 0.82 ppm (median=0.74 ppm, sd.=0.41). The average content of bioavailable cobalt in these sediments is close to its level in sediments of the cultivated floodplain (p=0.237) and the nearby wadi deposits (p=0.469).

Regarding the distribution pattern of bioavailable cobalt in the lands

applied for wastewater disposal at El-Dair (Table 23), it varies between 0.20 and 1.59 ppm (mean=0.50, median=0.36 ppm, sd.=0.38) in the wastewater farmlands. The estimated bioavailable cobalt content in the farmlands, in average, is slightly lower than that reported for the wadi deposits (p=0.299).

The bioavailable cobalt content measured in the surficial sediments of the

wastewater ponds at El-Dair (Table 23) covers a range varying from 0.24 to 1.47 ppm (mean=0.62, median=0.50 ppm, sd.=0.40). The average content of bioavailable cobalt in these sediments is very close to that of the nearby wadi deposits.

5.2.1.4 Nickel (Ni)

Rashad et al. (1995) gave a range from 0.38 to 1.34 ppm with an average of 0.66 ppm for available nickel. Aboulroos et al. (1996) recorded 0.30-1.02 ppm with an average of 0.64 ppm for available nickel in the Nile Delta soils. Omran et al. (1996) recorded 0.15 to 0.35 ppm for available nickel in these soils.

Concerning contaminated soils in Egypt; many investigators studied the

effect of irrigation with wastewater on soil pollution with nickel. El-Sayed (1993) reported that the available content of nickel in contaminated alluvial soils of El-Fayoum ranged between 0.44-1.34 ppm with an average of 0.87 ppm. Abou-Hussien and El-Koumy (1997) showed that the amounts of available nickel were 2.085 to 3.82 ppm, in the contaminated soils irrigated by wastewater in Menofiya Governorate.

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In the present study, the minimum, maximum, median, lower quartile (25%) and upper quartile (75%) of bioavailable nickel content through the various landuses are displayed in the box-whisker graph given in figure (53). A geochemical contour map showing the spatial distribution pattern of bioavailable nickel through the study area is displayed in figure (54).

The bioavailable nickel content estimated in the cultivated floodplain

(Table 19) varies from 0.59 to 1.83 ppm (mean=0.96, median=0.91 ppm, sd.=0.29). The average concentration of bioavailable nickel in the cultivated floodplain is relatively higher than the values (0.66 and 0.64 ppm) reported by Rashad et al., (1995) and Aboulroose et al., (1996).

The measured bioavailable content of nickel in the reclaimed lands (Table

20) ranges from 0.19 to 4.04 ppm (mean=0.91, median=0.69 ppm, sd.=0.71). This fraction, in average, is very close to that reported for the cultivated floodplain (p=0.713).

The bioavailable nickel concentrations estimated in the examined wadi

deposits (Table 21) fluctuate in the range 0.19-2.31 ppm (mean=0.65, median=0.49 ppm, sd.=0.38). On the average, it is relatively lower than that reported for the cultivated floodplain (p=0.009).

The levels of bioavailable nickel in the lands applied for wastewater

disposal at El-Kola (Table 22) range between 0.30 and 34.6 ppm with a mean value of 4.49 ppm (median=0.78 ppm, sd.=9.79). The average content of bioavailable nickel content in these sediments is significantly higher than its level in the cultivated floodplain (p=0.024). Although these sediments display insignificant difference of the bioavailable nickel content compared with the wadi deposits (p=0.091), markedly elevated values were recorded in some samples reaching up to 34.6 ppm. El-Sayed (1993) reported that the available nickel ranged between 0.44 ppm, and 1.34 ppm with an average of 0.87 ppm in contaminated alluvial soils in El-Fayoum. Similar observations were found by

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Omran et al. (1996) and Faiyad et al. (1997). According to Swain (1955), Rankhama and Sahama (1968) and Pierce et al. (1982), the concentrations of extractable nickel in a variety of polluted soils were low.

Regarding the bioavailable nickel content in the wastewater farmlands at

El-Dair (Table 23), it ranges from 0.21 to 4.17 ppm (mean=1.25, median=0.76 ppm, sd.=1.3). Such level of nickel, on the average, is close to that of the cultivated floodplain and wadi deposits (p=0.203 and 0.091, respectively).

The bioavailable nickel concentration measured in the surficial sediments

of the wastewater ponds at El-Dair (Table 23) varies from 0.33 to 5.72 ppm (mean=1.49, median=0.83 ppm, sd.=1.61). On the average, it is similar to that of the cultivated floodplain (p=0.059).

Reviewing the distribution pattern of the bioavailable nickel content in the

lands applied for wastewater disposal, elevated values were reported only in some samples from El-Kola site. The occasional elevated levels of bioavailable nickel content at El-Kola may imply that a considerable fraction of nickel is transported as mobile form by wastewater disposed of into this site.

5.2.1.5 Chromium (Cr)

Soil chromium is largely unavailable because it occurs in relatively insoluble compounds (Mengel and Kirkby, 1978). Cary (1982) found that chromium appears to offer little cause for concern as toxic environmental pollutants. Generally, soluble chromium concentrations would not reach 5 ppm except near the source of pollution.

The box-whisker graph displayed in figure (55) exhibits the minimum,

maximum, median, lower quartile (25%) and upper quartile (75%) of bioavailable chromium content among the concerned landuses. A geochemical contour map showing the spatial distribution of bioavailable chromium through the study area is displayed in figure (56).

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Regarding the cultivated floodplain (Table 19), the bioavailable chromium

content ranges from 0.003 to 0.214 ppm (mean=0.068, median=0.060 ppm, sd.=0.040). The estimated concentrations of bioavailable chromium in the reclaimed lands range from 0.022 to 0.440 ppm (mean=0.096, median=0.072 ppm, sd.=0.081). Generally, the bioavailable chromium content of the reclaimed lands (Table 20), in average, is very close to that reported for the cultivated floodplain (p=0.0708). Levels of the bioavailable chromium in the wadi deposits (Table 21) of the study area range from 0.020 to 0.518 ppm (mean=0.154, median=0.106 ppm, sd.=0.143). Wadi deposits exhibit significantly lower bioavailable chromium content than the cultivated floodplain (p<0.0018). The depleted level of the bioavailable chromium content in the floodplain, reclaimed lands and wadi deposits suggests that the major part of chromium is tightly contained in the crystal lattice of its bearing mineral phases.

Concerning the bioavailable chromium concentration in the lands applied

for wastewater disposal at El-Kola (Table 22), it varies from 0.018 to 0.366 ppm (mean=0.091, median=0.074, sd.=0.071). The average content of chromium in these sediments has insignificant difference with its levels in sediments of the Nile floodplain (p=0.098) and the wadi deposits (p=0.079).

The bioavailable chromium content estimated in the wastewater farmlands

at El-Dair (Table 23) fluctuates between 0.026 and 0.234 ppm (mean=0.087, median=0.074 ppm, sd.=0.053). The bioavailable chromium content, on the average, is close to that reported for the cultivated floodplain (p=0.186).

The total chromium level estimated in sediments of the wastewater ponds

at El-Dair (Table 23) ranges between 0.018 and 0.220 ppm (mean=0.111, median=0.106 ppm, sd.=0.064). The average bioavailable chromium content in these sediments is extremely similar to that of wadi deposits (p=0.029).

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It is clear that the bioavailable chromium content in the lands applied for wastewater disposal at El-Kola and El-Dair is markedly similar to that of the adjacent wadi deposits. This reveals that the wastewater disposal practice has no important influence on the chromium bioavailability at these two sites.

5.2.1.6 Lead (Pb)

Ruby et al. (1994) demonstrated that the forms of lead control the solubility and bioaccessibility of lead from soils. Norrish (1975) showed that lead is associated mainly with clay minerals, Mn, Fe and Al oxyhydroxides, and organic matter.


(75%) of the bioavailable lead content through the various landuses concerned in the present study are displayed in the box-whisker graph displayed in figure (57). The geochemical contour map given in figure (58) shows the spatial distribution pattern of lead throughout the investigated area.

The bioavailable lead content estimated in the cultivated floodplain

(Table 19) varies from 0.52 to 2.08 ppm (mean=0.97, median=0.90 ppm, sd.=0.35). Rashad et al. (1995) found that the normal level of available lead in the alluvial soils of Nile Delta ranged from 1.4 to 2.5 ppm with an average of 1.9 ppm. Aboulroos et al. (1996) recorded the range 0.78-2.46 ppm with an average of 1.39 ppm for the available lead in these soils. A range of 0.46-1.03 ppm available lead was found for some alluvial soils in Assiut (Gomah, 2001).

The measured lead content in the reclaimed lands (Table 20) ranges from

0.28 to 6.16 ppm (mean=1.36, median=0.92 ppm, sd.=1.29). This bioavailable lead content, in average, is close to that reported for the cultivated floodplain (p=0.093), although elevated values were reported at some sites. These sites are situated very close to either the Pliocene clay or the lands applied for wastewater disposal.

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The bioavailable lead concentrations estimated in the examined wadi deposits (Table 21) fluctuate in the range 0.46-9.18 ppm (mean=1.79, median=1.00 ppm, sd.=2.28). On the average, it is relatively higher than that reported for the cultivated floodplain (p=0.041).

The levels of bioavailable lead in the lands applied for wastewater disposal

at El-Kola (Table 22) range between 0.26 and 14.1 ppm with an average of 2.49 ppm (median=1.34 ppm, sd.=3.13). The average content of bioavailable lead in these sediments is significantly higher than its level in the cultivated floodplain (p=0.006), while there is insignificant difference with that recorded in the wadi deposits (p=0.427).

Regarding the bioavailable lead of the wastewater farmlands at El-Dair

(Table 23), it ranges from 0.40 to 9.20 ppm (mean=2.32, median=1.38 ppm, sd.=2.48). Such level of lead, on the average, is close to that of the surrounding wadi deposits (p=0.529).

The bioavailable lead concentration measured in the surficial sediments of

the wastewater ponds at El-Dair (Table 23) varies from 0.64 to 4.90 ppm (mean=1.93, median=1.64 ppm, sd.=1.03). On the average, it is extremely similar to that of the wadi deposits (p=0.828).

The distribution pattern of the bioavailable lead content throughout the

lands applied for wastewater at El-Kola and El-Dair shows elevated level in some sites reaching up to 14.1 ppm. This indicates that the effect of wastewater disposal on the lead bioavailability is occasional.

5.2.1.7 Zinc (Zn)

Viets and Lindsay (1973) reported that the DTPA extractable zinc in soils varies from 0.5 to 1.0 ppm. Regarding bioavailable zinc in Egypt, Rashad et al. (1995) found that zinc levels in soil ranged between 2.6 and 9.6 ppm with an average of 6.31 ppm. Aboulroos et al. (1996) reported that bioavailable zinc in

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non-polluted soils of the Nile Delta ranged between 0.73 and 4.44 ppm with an average of 2.1 ppm. Abou Yuossef (1999) found that the available zinc concentration ranged from 0.83 to 4.76 ppm with a geometric mean of 2.95 ppm.

The box-whisker graph given in figure (59) shows the minimum,

maximum, median, lower quartile (25%) and upper quartile (75%) of bioavailable zinc content through the considered landuses. The spatial distribution of bioavailable zinc through the study area is displayed in figure (60).

The bioavailable zinc content estimated in the cultivated floodplain

(Table 19) varies from 0.45 to 1.89 ppm (mean=0.97, median=0.84 ppm, sd.=0.36). These values are in agreement with those found in the soils of Egypt by Ghoneim et al., (1984b); Attia, (1988) and Gomah (2001).

The measured zinc content in the reclaimed lands (Table 20) ranges from

0.28 to 23.1 ppm (mean=1.99, median=1.13 ppm, sd.=3.93). The bioavailable zinc content, in average, has insignificant difference with that reported for the cultivated floodplain (p=0.129). Despite the marked similarity of the bioavailable zinc content between the wadi deposits and the cultivated floodplain, elevated levels were reported in some samples reaching up to 23.1 ppm. These samples are situated very close to the lands applied for wastewater disposal.

The bioavailable zinc concentrations estimated in the examined wadi

deposits (Table 21) fluctuate in the range 0.16-7.88 ppm (mean=0.97, median=0.43 ppm, sd.=1.82). On the average, it is close to that reported for the cultivated floodplain (p=0.999).

The levels of bioavailable zinc in the lands applied for wastewater disposal

at El-Kola (Table 22) range between 0.16 and 106.9 ppm with an average of 10.9 ppm (median=1.01 ppm, sd.=24.7). The bioavailable zinc content in these sediments is significantly higher than its level in the cultivated floodplain and the adjacent wadi deposits.

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Regarding the bioavailable zinc content in the wastewater farmlands at El-Dair (Table 23), it ranges from 0.68 to 81.3 ppm (mean=20.9, median=8.42 ppm, sd.=23.1). Such level of zinc, on the average, is significantly higher than that of the wadi deposits and cultivated floodplain (p=0.001 for both). Similar results were reported in other studies (e.g. El-Saady, 1991; Hegazy, 1993; Ramadan, 1995; Rabie et al. 1996).

The bioavailable zinc concentration measured in the surficial sediments of

the wastewater ponds at El-Dair (Table 23) varies from 1.17 to 193.9 ppm (mean=28.7, median=10.3 ppm, sd.=49.6). On the average, it is extremely higher than that of the floodplain (p=0.002) and wadi deposits (p=0.028).

Regarding the distribution pattern of the bioavailable zinc content in the

lands applied for wastewater disposal, it is obvious that markedly elevated levels are reported in some samples. Generally, samples possessing elevated zinc content are those enriched with the organic matter confirming that the disposed wastewater is the main source of the bioavailable zinc.

5.2.1.8 Copper (Cu)

Singh et al. (1969) reported a range of 1.50 to 1.9 ppm available copper in the Indian soils. Lower availability of copper was attributed in some cases to the high percentage of sand. In the alluvial soils of Egypt a range of 0.05 to 3.73 ppm, with an average of 0.88 ppm, was reported (El-Sayed, 1971). Lower values were reported by Abd El-Razek (1969) and El-Gibaly et al. (1970), where they reported values around 0.35 ppm. Ghoneim et al. (1984b) reported values of available copper in soils of Upper Egypt in the range of 0.06 to 4.55 ppm, with an average of 1.74 ppm. Ismaeil (1993) reported available copper ranged from 0.2 to 2.0 ppm. Kishk et al. (1973) found that it varies between 0.2 and 19.7 ppm. Aboulroos et al. (1996) found that the normal level of available copper in alluvial soils of the Nile Delta ranges between 1.26 and 3.78 ppm, with an average of 2.18 ppm.

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The minimum, maximum, median, lower quartile (25%) and upper quartile (75%) of the bioavailable copper content in the study area are displayed in the box-whisker graph shown in figure (61). The spatial distribution pattern of copper through the study area is shown in the geochemical contour map given in figure (62).

The bioavailable copper content estimated in the cultivated floodplain

(Table 19) varies from 2.04 to 4.82 ppm (mean=3.52, median=3.64 ppm, sd.=0.81). Gomah, (2001) reported that available copper in some soils of Assiut falls in the range 1.70-3.93 ppm. Ghoneim et al., 1984, found that available copper varies from 0.59 to 4.03 ppm in the soils of Sohag with an average of 1.83 ppm.

The measured copper content in the reclaimed lands (Table 20) ranges from

0.14 to 6.58 ppm (mean=2.31, median=2.16 ppm, sd.=1.36). This bioavailable copper content, in average, is significantly lower than that reported for the cultivated floodplain (p<0.001).

The bioavailable copper concentrations estimated in the examined wadi

deposits (Table 21) fluctuate in the range 0.16-3.40 ppm (mean=0.96, median=0.70 ppm, sd.=0.78). On the average, it is significantly lower than that reported for the cultivated floodplain (p<0.001). These results are in agreement with finding of Gomha (2001) as well as those reported by Rashad (1986).

The levels of bioavailable copper in the lands applied for wastewater

disposal at El-Kola (Table 22) range between 0.02 and 7.62 ppm with a mean of 1.16 ppm (median=0.94 ppm, sd.=1.48). The average content of bioavailable copper content in these sediments is significantly lower than its level in the cultivated floodplain (p<0.001). Although there is insignificant difference of copper content compared with the wadi deposits (p=0.517), most samples are extremely depleted in their bioavailable copper content. Few samples show relatively higher content of the bioavailable copper; these samples are extremely affected by the very close Pliocene clay.

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Regarding the bioavailable copper content in the wastewater farmlands at El-Dair (Table 23), it ranges from 0.18 to 3.00 ppm (mean=0.96, median=0.70 ppm, sd.=0.93). Such levels of copper, on the average, are close to that of the wadi deposits (p=0.950) and significantly lower than that of the cultivated floodplain (p<0.001).

The bioavailable copper concentration measured in the surficial sediments

of the wastewater ponds at El-Dair (Table 23) varies from 0.20 to 2.52 ppm (mean=0.81, median=0.54 ppm, sd.=0.68). On the average, it is slightly lower than that of wadi deposits.

Reviewing the distribution pattern of the bioavailable copper content in the

lands applied for wastewater disposal, it was found that copper is extremely depleted in samples possessing higher content of organic matter. This indicates that the copper bioavailability is reversely affected by the wastewater disposal practice as it forms a stable complex with organic compounds (see Jones and Turki, 1997; Li et al., 2000; Li and Thornton, 2001; Omer, 2003a).

5.2.1.9 Cadmium (Cd)

The primary form of cadmium in soil is the free metal and hydroxides, although it may form complexes with chloride, sulfur, carbonates, and organic matter. Significant sinks of cadmium in sediments include organics, sulfides, carbonates, clay minerals, and oxides and hydroxides of Fe and Mn (Khaled, 1980). Cadmium in soil may be found in forms that range from sparingly, moderately to highly soluble. This information suggests that cadmium in soils will exhibit a wide range of bioavailability (NEPI, 2000).

The box whisker graph given in figure (63) shows the minimum,

maximum, median, lower quartile (25%) and upper quartile (75%) of the bioavailable cadmium content through the study area. A geochemical contour map displaying the distribution pattern of bioavailable cadmium through the study area is displayed in figure (64).

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The bioavailable cadmium content estimated in the cultivated floodplain

(Table 19) varies from 0.016 to 0.057 ppm (mean=0.025, median=0.024 ppm, sd.=0.006).

The measured cadmium content in the reclaimed lands (Table 20) ranges

from 0.015 to 0.213 ppm (mean=0.034, median=0.024 ppm, sd.=0.037). The bioavailable cadmium content, in average, has no significant difference with that reported in the cultivated floodplain (p=0.181), and wadi deposits (p=0.070).

The bioavailable cadmium concentrations estimated in the examined wadi

deposits (Table 21) fluctuate in the range 0.015-0.195 ppm (mean=0.061, median=0.028 ppm, sd.=0.068). On the average, it is significantly higher than that reported for the cultivated floodplain (p=0.003).

The levels of bioavailable cadmium in the lands applied for wastewater

disposal at El-Kola (Table 22) ranges between 0.014 and 0.317 ppm with an average of 0.0.041 ppm (median=0.027 ppm, sd.=0.055). The average content of bioavailable cadmium content in these sediments is close to its level in the adjacent wadi deposits (p=0.280).

Regarding the bioavailable cadmium content in the wastewater farmlands

at El-Dair (Table 23), it ranges from 0.010 to 0.344 ppm (mean=0.0.61, median=0.017 ppm, sd.=0.094). Such level of cadmium, on the average, is close to that of wadi deposits (p=0.998) and significantly higher than that of the cultivated floodplain (p=0.028).

The bioavailable cadmium concentration measured in the surficial sediments of the wastewater ponds at El-Dair (Table 23) varies from 0.010 to 0.045 ppm (mean=0.022, median=0.019 ppm, sd.=0.010). On the average it is extremely similar to that of the wadi deposits (p=0.1258).

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Regarding the bioavailable cadmium content in the lands applied for

wastewater disposal at El-Kola and El-Dair, it is very closely akin to that of the nearby wadi deposits. This means that the wastewater disposal practice has no effect on the cadmium bioavailability in these sites. Table (19): Summary of descriptive statistics for the bioavailable heavy metals content

(ppm) in the cultivated floodplain (n= 35)

Cd Cu Zn Pb Cr Ni Co Mn Fe 0.025 3.52 0.97 0.97 0.068 0.96 0.96 67.0 19.8 Mean 0.024 3.64 0.84 0.90 0.060 0.91 0.76 56.0 19.6 Median 0.016 2.04 0.45 0.52 0.003 0.59 0.34 17.9 3.2 Minimum 0.057 4.82 1.89 2.08 0.214 1.83 2.22 142.3 32.3 Maximum 0.006 0.81 0.36 0.35 0.040 0.29 0.55 35.5 6.1 sd. 0.022 2.82 0.66 0.74 0.096 0.78 0.5 41.7 15.6 25% percentile0.027 4.1 1.32 1.1 0.044 1.08 1.2 94.3 24.2 75% percentile

Table (20): Summary of descriptive statistics for the bioavailable heavy metals content

(ppm) in the reclaimed lands (n= 33)


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Table (21): Summary of descriptive statistics for the bioavailable heavy metals content (ppm) in the wadi deposits (n= 17)



(ppm) in lands applied for wastewater disposal at El-Kola (n= 29)

Cd Cu Zn Pb Cr Ni Co Mn Fe 0.041 1.16 10.87 2.49 0.091 4.79 0.82 41.2 120.8 Mean 0.027 0.94 1.01 1.34 0.074 0.78 0.74 29.4 41.4 Median 0.014 0.02 0.16 0.26 0.018 0.30 0.13 0.56 3.5 Minimum 0.317 7.62 106.89 14.08 0.366 34.59 1.62 184.8 526.0 Maximum 0.055 1.48 24.66 3.13 0.071 9.79 0.41 38.6 162.6 sd. 0.021 0.18 0.488 0.94 0.058 0.44 0.54 15.9 5.5 25% percentile 0.036 1.38 2.448 2.18 0.122 2.15 1.00 62.1 190.2 75% percentile


(ppm) in lands applied for wastewater disposal at El-Dair (farmlands and ponds, n=15 for both).

Cd Cu Zn Pb Cr Ni Co Mn Fe 0.061 0.96 20.942.32 0.087 1.25 0.50 38.8 334.3 Mean 0.017 0.70 8.421.38 0.074 0.76 0.36 42.4 283.9 Median 0.010 0.18 0.680.40 0.026 0.21 0.20 9.9 25.4 Minimum 0.344 3.00 81.339.20 0.234 4.17 1.59 67.2 878.3 Maximum 0.094 0.93 23.072.48 0.053 1.30 0.38 17.1 287.6 sd. 0.015 0.22 3.920.84 0.048 0.27 0.20 23.9 66.6 25% percentile 0.036 1.42 38.762.36 0.104 1.93 0.72 51.8 522.3

Farm

land

s

75% percentile 0.022 0.81 28.701.93 0.111 1.49 0.62 40.3 333.4 Mean 0.019 0.54 10.251.64 0.106 0.83 0.50 30.5 261.2 Median 0.010 0.20 1.170.64 0.018 0.33 0.24 12.1 99.9 Minimum 0.045 2.52 193.884.90 0.220 5.72 1.47 89.7 981.3 Maximum 0.010 0.68 49.611.03 0.064 1.61 0.40 25.5 249.4 sd. 0.015 0.34 6.521.44 0.058 0.54 0.28 16.9 124.5 25% percentile 0.024 1.02 21.962.46 0.174 2.17 0.90 58.9 403.4 W

aste

wat

er p

onds

75% percentile

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Fe

(ppm

)

1

10

100

1000

1 2 3 4 5

1- Cultivated floodplain 2- Reclaimed lands 3- Wadi deposits4- Wastewater disposal site at El-Kola5- Wastewater disposal site at El-Dair

MaxMin75%25%Median


(25%) and upper quartile (75%) of bioavailable iron content (ppm) in the studied sediments.

ppm

26 3

2 00

N26

28

00 N

26 3

2 00

N26

28

00 N

31 32 00 E 31 36 00 E 31 40 00 E 31 44 00 E 31 48 00 E 31 52 00 E



Kilometers02.5 55

31 32 00 E 31 36 00 E 31 40 00 E 31 44 00 E 31 52 00 E31 48 00 E

25

50

75

100

125

150

175

200

Fig. (48): Distribution of the bioavailable iron content in the study area.

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M

n (p

pm)

0.5

1.0

5.0

10.0

50.0

100.0

1 2 3 4 5

Fig. (49): A box-whisker graph showing the minimum, maximum, median, lower quartile (25%) and upper quartile (75%) of bioavailable manganese content (ppm) in the studied sediments. See figure (47) for explanation.

ppm

26 3

2 00

N26

28

00 N

26 3

2 00

N26

28

00 N

31 32 00 E 31 36 00 E 31 40 00 E 31 44 00 E 31 48 00 E 31 52 00 E



Kilometers02.5 55

31 32 00 E 31 36 00 E 31 40 00 E 31 44 00 E 31 52 00 E31 48 00 E

25

75

125

175

225

275

Fig. (50): Distribution of the bioavailable manganese content in the study area.

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C

o (p

pm)

0.1

0.2

0.4

0.6

0.8

1.0

2.0

1 2 3 4 5

Fig. (51): A box-whisker graph showing the minimum, maximum, median, lower quartile (25%) and upper quartile (75%) of bioavailable cobalt content (ppm) in the studied sediments. See figure (47) for explanation.

0.6

1.2

1.8

2.4

3

ppm

26 3

2 00

N26

28

00 N

26 3

2 00

N26

28

00 N

31 32 00 E 31 36 00 E 31 40 00 E 31 44 00 E 31 48 00 E 31 52 00 E



Kilometers02.5 55

31 32 00 E 31 36 00 E 31 40 00 E 31 44 00 E 31 52 00 E31 48 00 E

Fig. (52): Distribution of the bioavailable cobalt content in the study area.

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N

i (pp

m)

0.1

0.5

1.0

5.0

10.0

1 2 3 4 5

Fig. (53): A box-whisker graph showing the minimum, maximum, median, lower quartile (25%) and upper quartile (75%) of bioavailable nickel content (ppm) in the studied sediments. See figure (47) for explanation.

ppm

26 3

2 00

N26

28

00 N

26 3

2 00

N26

28

00 N

31 32 00 E 31 36 00 E 31 40 00 E 31 44 00 E 31 48 00 E 31 52 00 E



Kilometers02.5 55

31 32 00 E 31 36 00 E 31 40 00 E 31 44 00 E 31 52 00 E31 48 00 E

0.5

2

3.5

5

6.5

8

9.5

Fig. (54): Distribution of the bioavailable nickel content in the study area.

HEAVY METALS

154

C

r (pp

m)

0.005

0.010

0.050

0.100

0.500

1 2 3 4 5

Fig. (55): A box-whisker graph showing the minimum, maximum, median, lower quartile (25%) and upper quartile (75%) of bioavailable chromium content (ppm) in the studied sediments. See figure (47) for explanation.

0.1

0.2

0.3

0.4

0.5

ppm

26 3

2 00

N26

28

00 N

26 3

2 00

N26

28

00 N

31 32 00 E 31 36 00 E 31 40 00 E 31 44 00 E 31 48 00 E 31 52 00 E



Kilometers02.5 55

31 32 00 E 31 36 00 E 31 40 00 E 31 44 00 E 31 52 00 E31 48 00 E

Fig. (56): Distribution of the bioavailable chromium content in the study area.

HEAVY METALS

155

Pb

(ppm

)

0.1

0.5

1.0

5.0

10.0

1 2 3 4 5

Fig. (57): A box-whisker graph showing the minimum, maximum, median, lower quartile (25%) and upper quartile (75%) of bioavailable lead content (ppm) in the studied sediments. See figure (47) for explanation.

1

2

3

4

5

6

7

8

9

ppm

26 3

2 00

N26

28

00 N

26 3

2 00

N26

28

00 N

31 32 00 E 31 36 00 E 31 40 00 E 31 44 00 E 31 48 00 E 31 52 00 E



Kilometers02.5 55

31 32 00 E 31 36 00 E 31 40 00 E 31 44 00 E 31 52 00 E31 48 00 E

Fig. (58): Distribution of the bioavailable lead content in the study area.

HEAVY METALS

156

Zn

(ppm

)

0.1

0.5

1.0

5.0

10.0

50.0

100.0

1 2 3 4 5

Fig. (59): A box-whisker graph showing the minimum, maximum, median, lower quartile (25%) and upper quartile (75%) of bioavailable zinc content (ppm) in the studied sediments. See figure (47) for explanation.

ppm

26 3

2 00

N26

28

00 N

26 3

2 00

N26

28

00 N

31 32 00 E 31 36 00 E 31 40 00 E 31 44 00 E 31 48 00 E 31 52 00 E



Kilometers02.5 55

31 32 00 E 31 36 00 E 31 40 00 E 31 44 00 E 31 52 00 E31 48 00 E

9

7

5

3

1

Fig. (60): Distribution of the bioavailable zinc content in the study area.

HEAVY METALS

157

C

u (p

pm)

0.01

0.05

0.10

0.50

1.00

5.00

1 2 3 4 5

Fig. (61): A box-whisker graph showing the minimum, maximum, median, lower quartile (25%) and upper quartile (75%) of bioavailable copper content (ppm) in the studied sediments. See figure (47) for explanation.

0.5

1.5

2.5

3.5

4.5

5.5

ppm

26 3

2 00

N26

28

00 N

26 3

2 00

N26

28

00 N

31 32 00 E 31 36 00 E 31 40 00 E 31 44 00 E 31 48 00 E 31 52 00 E



Kilometers02.5 55

31 32 00 E 31 36 00 E 31 40 00 E 31 44 00 E 31 52 00 E31 48 00 E

Fig. (62): Distribution of the bioavailable copper content in the study area.

HEAVY METALS

158

C

d (p

pm)

0.005

0.010

0.050

0.100

0.500

1 2 3 4 5

Fig. (63): A box-whisker graph showing the minimum, maximum, median, lower quartile (25%) and upper quartile (75%) of bioavailable cadmium content (ppm) in the studied sediments. See figure (47) for explanation.

0.05

0.15

0.25

0.35

ppm

26 3

2 00

N26

28

00 N

26 3

2 00

N26

28

00 N

31 32 00 E 31 36 00 E 31 40 00 E 31 44 00 E 31 48 00 E 31 52 00 E



Kilometers02.5 55

31 32 00 E 31 36 00 E 31 40 00 E 31 44 00 E 31 52 00 E31 48 00 E

Fig. (64): Distribution of the bioavailable cadmium content in the study area.

ASSESSMENT OF THE ENVIRONMENTAL CONSEQUENCES

CHAPTER 6 ASSESSMENT OF ENVIRONMENTAL

CONSEQUENCES


159

CHAPTER 6 ASSESSMENT OF THE ENVIRONMENTAL

CONSEQUENCES

6.1 Natural Background Levels Of Heavy Metals

The environmental pollution became a worldwide problem and took the attention of the different scientific authorities. Therefore, determination of natural background levels of heavy metals through the various geological materials (e.g. soil and sediments) is extremely useful.

Database on the natural levels of heavy metals in the uncontaminated

sediments and soil serves as a starting point to evaluate metal pollution risks in a certain ecosystem. Determination of the natural background levels of heavy metals in the surficial sediments of the study area is essential to:

• determine the accepted range of metals for the uncontaminated sediments, • determine if contamination exists, • detect the sites of contamination, • measure the contamination intensity, and • reveal and follow up changes in contamination state with time.

The range of background levels of total heavy metals for the

uncontaminated sediments of the cultivated floodplain, reclaimed lands and wadi deposits were statistically calculated (Table 24) to meet the median plus or minus twice the standard deviation of the distribution after excluding the anomalous values (outliers and extremes). The maximum allowable limits (MAL) of the various metals reported for the worldwide soil (Kabata-Pendias, 1995) were also listed.


160

Table (24): The calculated background values of the total metal (ppm) content for the cultivated floodplain, reclaimed lands and wadi deposits.

Metal Cultivated floodplain

Reclaimed lands

Wadi deposits MAL

Fe (%) 7.17 ± 2 5.20 ± 3.38 4.14 ± 2 ---- Mn 1343 ± 358 1150 ± 574 923 ± 418 ---- Co 37 ± 8 30 ± 12 30 ± 10 50 Ni 68 ± 12 56 ± 28 48 ± 12 100 Cr 159 ± 44 134 ± 60 145 ± 70 200 Pb 23 ± 8 23 ± 12 27 ± 10 100 Zn 147 ± 88 125 ± 98 160 ± 66 300 Cu 74 ± 16 53 ± 36 46 ± 50 100 Cd 0.77 ± 0.16 0.94 ± 0.50 1.3 ± 0.4 5

It is clear that sediments of the cultivated floodplain, reclaimed lands and

wadi deposits have perfect background values of the estimated heavy metals, where they rarely exceed the maximum allowable limit (MAL) reported for the worldwide soils (see Table 24).

Regarding the cultivated floodplain, only two sites (Nos. 115 and 32)

display anomalous levels of some metals exceeding the maximum allowable limit. Of which, site No.115 exhibits elevated levels of zinc (1249 ppm) and copper (244 ppm); these metals are most probably of anthropogenic source related to the special position of this site as stated above. The second site (No.32) shows natural abnormal level of nickel (119 ppm) that also surpasses the maximum allowable limit.

With respect to the concerned reclaimed lands, two sites have elevated

content of zinc and/or lead (Nos.71 and 124). Site No.124 has anomalous levels of zinc and lead (313 and 248 ppm, respectively), whereas site No.71 possesses abnormally higher value of zinc (401 ppm). The stated levels of zinc and lead in these two sites are markedly exceeding the maximum allowable limit (MAL). The two sites are evidently affected by wastewater effluent,


161

where site No.124 is located immediately close to the wastewater ponds at El-Dair, while site No.71 is frequently used for manual wastewater disposal. On the other hand, three sites (Nos. 8, 21 and 23) exhibit higher values of chromium (243, 202 and 204 ppm, respectively) surpassing the MAL used as a trigger level for contaminated soils (see Table 24). Such elevated values of chromium may follow the natural composition of the parent material, where no evidence for the anthropogenic accumulation was documented.

On the other hand, two sites (Nos.16 and 17) belonging to the studied wadi

deposits exhibit higher levels of copper (114 and 110 ppm, respectively); in addition, two sites (No.9 and 61) display elevated levels of chromium (280 and 253 ppm, respectively). The stated levels of the two metals are going beyond the maximum allowable limit. These sites are obviously influenced by the nearby Pliocene clays.

However, the lands applied for wastewater disposal at El-Kola and El-Dair

have been greatly affected by such improper practice, giving rise to variable grades of contamination. So, the environmental consequences of the improper wastewater disposal through these lands will be discussed in detail through the next section.

6.2 Environmental Consequences Of The Improper Wastewater Disposal

6.2.1 Introduction The wastewater disposal and its negative effects is actually a serious

environmental problem. Wastewater is a complex of mixed liquid wastes related to the various human activities. The relative quantities and composition of wastewater tend to vary widely throughout the different communities. Generally, wastewater contains many types of pollutants; the greatest threats arise from heavy metals, nitrates, pathogens, toxic organic and inorganic materials and salts (see Blumenthal, et al., 2001; Shuval, et al., 1989). The improper disposal of the untreated, or partially treated, wastewater can pose pollution of soil and water resources, and consequently affect the biosystem and human health adversely.


162

Over the past several years, land application of sewage wastewater has been becoming an increasingly common method of disposing in Egypt. In Sohag, as the general case in Upper Egypt, the traditional wastewater disposal regime in the peopled centers using inappropriate household cesspools has caused widespread environmental and health problems in both the rural and urban communities. It was thus very urgent to establish public sewage systems to safely get rid of such problematic wastewater. Land application is the only possible way for wastewater disposal along the Nile Valley in Upper Egypt. So, the plan was to use the wastewater in irrigating farmlands in the low-land desert zone extending between the cultivated floodplain and the higher relief Eocene limestone plateau. Eight sites have been already chosen for this purpose within Sohag district; of these, two sites (El-Dair and El-Kola) are presently operating for wastewater disposal while the others will be in use through the very near future.

The stated desert zone is really narrow and located very close to

fundamental objectives such as the cultivated floodplain, reclaimed lands, residential areas and surface water resources (River Nile and canals). Moreover, the subsurface water-bearing sediments (mainly sands and gravels) constitute the shallow Quaternary aquifer of the valley, which is considered as a vital water resource. Therefore, using the mentioned desert zone for wastewater disposal must be taken with great caution. Generally, open dumping of wastes is a real source of widespread environmental and health hazards (Christensen, 1989; Langer, 1995). Accordingly, geoscientific and environmental assessment should be made throughout the surrounding areas to find out the suitable sites for safe waste disposal (see Mansour, 2003).

The currently operating wastewater disposal sites (El-Dair and El-Kola)

are situated within the study area. The wastewater is improperly disposed of in the two sites where great quantities of raw wastewater are disposed without treatment. However, the improper land application of sewage wastewater disposal at the two sites might have serious environmental consequences. Quantification of the contamination status of soil and groundwater at the affected sites is a critical target.


163

Assessment of the negative effects of such improper land application of wastewater disposal on the environmental system in Sohag Governorate, and the whole valley, is a vital objective. The negative consequences of such practice on the different environmental issues have to be urgently appraised and promulgated aiming to give the appropriate recommendations at the right time.

6.2.2 The disposal sites and nature of the problem As has been already mentioned, the wastewater disposal site at El-Dair is

located about 10 km to the west of Sohag City (Fig.3). The source of effluent disposed into this site (more than 40,000 mP

3P/day) is the western division of

Sohag City situated on the western bank of the Nile. This means that about 15 billion cubic meters of sewage effluent are disposed of into this site every year. The potential for contamination of soil and groundwater is, therefore, strongly expected; the matter which needs to be researched and assessed. This site lies in the wadi deposits bordered by the Eocene limestone plateau from the west and the cultivated floodplain from the east. The ground surface shows a general eastward slope toward the cultivated land. The area is occupied by a thick succession of sandy and gravelly Pleistocene sediments (Fig.65) covered with a thin layer of Recent wadi deposits (sandy gravel) ranging in thickness from 1m to more than 10m (Omer, 1996). The subsurface sediments are highly porous and permeable, and constitute a part of the groundwater reservoir of the Nile Valley. The groundwater in the area is shallow with a depth ranging from 15m at the eastern side to 30 m at the western border of the disposal site. The higher effective permeability and infiltration capacity of these sandy and gravelly sediments can result in a rapid downward percolation of wastewater into the groundwater (El-Haddad and El-Shater, 1988) with little chance for pollutants removal. The very low content of clay minerals, which are able to absorb significant portion of pollutants, in these sediments is aggravating the problem. Groundwater pollution is thus inevitable at this site upon rapid downward movement of pollutants, and serious risks are extremely expected particularly in the very close residential areas through the numerous groundwater wells scattered in the region.


164

Fig. (65): Schematic cross section showing the land applied for wastewater disposal at El

Dair and the subsurface sediment layers. Percolation of wastewater into the groundwater is displayed.

On the other hand, different types of crops are grown on the highly

contaminated soils of the farmlands irrigated by the wastewater. The production of these farmlands is illegally distributed. In addition, broad areas of reclaimed lands surround the disposal site at El-Dair. The farmers surreptitiously use the raw wastewater, carrying various pollutants and biosolids, in irrigating their lands without supervision or even restriction on type of crops. The main crops grown are vegetables, which are largely distributed in the different markets within Sohag Governorate. Consequently, the potentially harmful pollutants can enter the food chain to endanger the public health; and hence, various health risks are unavoidable (see Kumar and Clark, 1991; Feenstra et al., 2000; NRC, 2003). The problem of metal toxicity may be enhanced as a result of their accumulation by seemingly healthy plants to reach concentrations that might endanger human health (Harris, et al., 1996).

The disposal site at El-Kola lies about 13 km east of Sohag in the desert

area enclosed between the Eocene limestone plateau from the east and the River Nile from the west (Fig.3). More than 15,000 mP

3P/day, as a first stage, of raw

wastewater are currently disposed of into this site from the eastern part of Sohag City. This site is situated very close to the vital surface water resources including the River Nile course and the Nag Hammadi El-Sharqiya Canal.


165

The land surface is steeply sloping westward toward these water bodies. The whole area is occupied by a thin layer of highly permeable sandy gravel sediments, ranging from 0.5 to 8 m, resting on a thick succession of dense and impermeable Pliocene clay (Fig. 66).

The improper wastewater disposal at this site is enormously dangerous.

The higher permeability of the thin surface layer, which is wastewater-bearing, and its steep slope leads to percolating potential quantities of wastewater into the shallow groundwater and the nearby surface water bodies. The Nile, which is referred to as the life-blood of Egypt, is the main water resource and the mentioned canal (Nag Hammadi El-Sharqyia) is used further downstream as a public drinking water source. Also, water is pumped from the shallow groundwater by the privates to be used for the different domestic purposes. Pollution of such water resources is considered as a disastrous environmental problem being threaten the public health. The problem will be enlarged with increasing the amount of wastewater requiring disposal in the near future, through the second stage.

Fig. (66): Schematic cross section showing the land applied for wastewater disposal at El

Kola and the subsurface sediment layers. Percolation of wastewater into the groundwater and the nearby surface water is displayed.


166

6.3 Soil And Groundwater Contamination 6.3.1 Soil 6.3.1.1 Total metal content

The distribution and variability of the total heavy metals content in the study area were discussed in the preceding chapter. Here, assessment of the environmental status related to soil contamination by elevated levels of heavy metals in the lands applied for wastewater disposal is the main goal.

Lands applied for wastewater disposal (farmlands, wetlands and ponds) at

both El-Dair and El-Kola sites show potentially higher concentrations of zinc, lead and copper, on the average, relative to the corresponding wadi deposits. The elevated levels of these metals are generally associated with higher contents of organic matter reflecting the improper treatment of wastewater. The matter which indicates that zinc, lead and copper are significantly loaded by wastewater and the associated biosolids. Cobalt and cadmium content are very close to that of the nearby background level suggesting that they carried by the disposed wastes is trivial. Although nickel and chromium display no additional accumulation at El-Dair, they show considerable higher content at El-Kola site. The occasional high rate accumulation of these two metals at El-Kola site (sampling carried out after only one year of starting disposal) may be attributed to the effect of the nearby Pliocene clay (Omer, personal commentation).

The extent of contaminated of soil can be appraised by comparing the

metals content with the maximum allowable limits (MAL) used for the worldwide soils (see Kabata-Pendias, 1995) (Table 24). Regarding the lands applied for wastewater disposal, about 60% of El-Dair and 66% of El-Kola samples display higher concentrations of one or more of the metals: zinc, lead, copper and chromium, exceeding the MAL to reflect their significant contamination status. Nickel is generally lower than the MAL, although some soil samples from El-Kola exhibit slightly higher level. Cobalt content never exceeds the stated limit.

However, to quantify the degree of metal pollution from anthropogenic

activities, the Cultural Enrichment Factor (CEF) proposed by Fergusson (1990)


167

is very useful (see Siegel et al., 1994). The CEF is obtained by dividing the measured metal content by its natural baseline value. The higher CEF values (Table 25) reflect the more contamination conditions. The CEF was calculated for the examined soil samples considering the median values of metal contents in the wadi deposits as the natural baseline level (background). The total metal contents of lead, zinc and copper show wide range of CEF at the lands applied for wastewater disposal suggesting variable degrees of contamination. The highest values of CEF for lead, zinc and copper recorded at El-Dair site are 11.5, 8.9 and 4.9, respectively. The equivalent values at El-Kola are 6.5, 5.0 and 7.4. Such enhanced CEF values reveal critical accumulation of the anthropogenically-derived metals in these lands. The general higher values of CEF for lead, zinc and copper at El-Dair relative to El-Kola reflect the longer-term wastewater disposal (≈ 15 year) at the former site. The CEF of nickel and chromium are mostly less than one at El-Dair whereas it is relatively higher at El-Kola site (up to 2.6 and 2.0, respectively). This indicates that no additional build up of nickel and chromium are found at El-Dair, while there is an occasional accumulation at El-Kola; this may be controlled by the compositional characteristics of the wastewater disposed of into this site, as well as the effect of the Pliocene clay as a source material (see Omer, 1996). On the other hand, the total contents of cobalt and cadmium display CEF values fluctuating around one in most samples at the two sites, indicating no anthropogenic accumulation of these metals.

In order to monitor the impact of wastewater disposal on the soil heavy metals content, geochemical maps were constructed for the affected sites together with the surrounding lands that serve as geochemical background. Such geochemical maps visually display the spatial distribution of metals in the investigated sites and the potentially hazard spots can be easily identified (Goodchild et al., 1993). In the present section, the spatial variation of the environmentally-relevant metals (Zn, Pb, Cu, Ni, Cr, Co and Cd) in the lands applied for wastewater disposal (El-Dair and El-Kola) is displayed on geochemical contour maps (Figs. 67 & 68). The local geochemical anomalies of these metals at the areas of effluent application are strictly pronounced.


168

Table (25): The culture enrichment factor (CEF) of the total metal content for soil

samples from lands applied for wastewater disposal.

El-Kola El-Dair ID Co Ni Cr Pb Zn Cu Cd ID Co Ni Cr Pb Zn Cu Cd

34 1.1 1.1 1.2 1.1 1.2 1.4 1.0 94 0.7 0.9 0.8 2.4 4.9 3.3 0.8 35 0.9 0.7 0.8 1.2 0.7 1.6 1.5 95 0.9 0.7 1.1 1.0 1.4 1.0 0.9 36 1.0 0.9 0.7 1.2 0.9 1.6 1.5 96 0.8 0.7 1.1 3.4 1.6 0.8 1.2 37 1.0 1.0 0.7 1.1 1.1 2.4 1.1 97 0.8 0.9 0.7 1.9 3.2 2.4 0.9 38 1.2 1.0 0.9 1.1 0.9 4.0 1.2 98 0.9 0.8 1.2 1.0 1.1 1.2 0.7 39 1.2 1.1 1.1 1.0 1.3 2.0 1.3 127 0.9 0.8 1.2 1.4 1.3 1.1 0.8 40 1.1 1.0 1.0 1.1 0.9 1.6 1.1 128 0.9 0.7 0.7 1.6 0.9 0.5 1.0 41A 1.0 1.1 1.1 1.8 2.1 3.9 1.1 129 0.5 0.7 0.8 5.4 3.5 2.5 0.6 41B 1.0 1.2 1.1 2.0 2.1 2.5 1.1 130 0.4 0.6 0.6 1.9 1.6 1.0 0.4 42 1.0 1.2 0.9 1.4 4.0 2.0 0.8 131 0.6 1.0 1.0 6.9 8.9 4.9 0.6 43 1.8 1.9 1.7 1.1 1.3 2.3 0.9 134 0.7 0.8 1.0 2.4 2.7 2.0 0.8 44 1.6 1.7 1.4 1.1 1.1 2.7 0.8 135 0.7 1.0 1.1 6.4 3.4 2.6 0.6 45 1.3 1.3 1.6 0.6 1.0 1.2 0.7 136 0.7 0.7 1.1 2.5 1.7 1.3 0.7 46 1.3 1.2 1.2 0.9 0.9 2.4 0.8 137 0.8 0.8 0.9 1.6 1.6 1.3 0.7 47 1.3 1.6 2.0 0.9 0.8 1.8 0.7

Was

tew

ater

f

arm

land

s

138 0.6 1.2 0.8 5.3 5.4 4.5 0.7 48 1.5 1.9 1.8 0.9 1.1 2.0 0.8 89 0.7 0.6 0.6 0.9 1.3 0.7 0.9 49 1.2 1.5 1.3 0.9 0.9 1.9 0.6 90 0.8 0.8 0.9 1.2 1.5 1.4 0.9 50 1.4 1.7 1.6 0.8 1.2 2.4 0.8 91 0.7 0.7 1.0 1.1 2.4 2.0 0.9 51 0.9 0.9 0.7 1.1 0.7 0.9 1.1 92 0.8 1.0 1.0 2.2 2.7 2.9 0.9 53 1.1 1.5 1.3 1.1 1.0 2.2 0.9 93 1.3 1.4 1.5 9.7 1.0 1.9 0.7 80 1.2 2.1 0.7 1.2 0.8 2.0 1.4 99 1.3 1.3 1.1 0.9 1.2 1.3 0.7 82 1.0 1.0 0.6 1.1 0.9 1.5 1.3 100 1.3 1.2 1.2 0.9 1.3 1.5 0.7

140 0.8 2.3 1.4 6.3 4.1 5.8 0.9 119 0.6 0.7 0.8 2.3 5.5 0.9 0.8 141 0.8 2.6 1.7 6.5 4.5 7.4 0.9 120 0.6 0.6 0.7 1.6 2.0 0.9 0.8 142 0.9 2.3 1.4 5.7 5.0 4.6 0.9 121 0.6 0.9 0.7 2.5 2.0 1.3 0.7 143 0.7 2.2 1.3 5.5 3.9 4.5 0.9 122 0.5 0.5 1.4 11.3 1.8 1.1 0.7 144 0.9 1.8 1.3 6.1 3.3 3.8 0.9 123 0.6 0.6 0.9 4.8 1.6 1.0 0.8 145 0.9 1.9 1.5 5.8 3.7 3.9 0.9 126 0.8 0.9 0.8 2.3 3.4 1.6 0.9

139 0.7 1.1 1.0 7.6 5.6 3.8 1.1

Was

tew

ater

pon

ds a

nd w

etla

nds

Was

tew

ater

p

onds

155 0.7 1.2 1.0 8.8 6.5 4.8 0.7

6.3.1.2 Bioavailable metal content

As has been already stated, metal bioavailability means its availability to be taken into the biosystem, directly or indirectly. So, the bioavailable fraction of metals in the geologic media is very important in the concerns of environmental geochemistry. It is important to evaluate the availability and mobility of heavy metals to establish environmental guidelines particularly for the potentially toxic metals, and to understand the chemical behavior and fate of contaminants in polluted sediments and soil (Davies, 1980).


169

The estimated bioavailable concentrations (DTPA-extractable) of heavy metals in the surficial sediments throughout the study area were discussed in the former chapter. A special attention will be paid here to the distribution pattern of the bioavailable metal contents in the lands applied for wastewater disposal and discuss their environmental impact.

The spatial distribution of the estimated bioavailable concentrations

(DTPA-extractable) of Zn, Pb, Cu, Ni, Cr, Co and Cd at the two investigated sites is displayed on the geochemical contour maps (Figs.69 & 70).

Zinc shows the highest bioavailable content among the estimated heavy

metals. The recorded level at El-Dair, on the average, is generally higher than that of El-Kola. About 57% of the examined samples from the former site contain bioavailable zinc higher than 10 ppm, whereas 21% of El-Kola samples exceed this level. Despite the wide range of bioavailable zinc at these two sites, extremely elevated concentrations were recorded (up to 94 ppm at El-Dair and 107 ppm at El-Kola). The CEF of the bioavailable zinc is generally elevated at El-Dair site (Table 26). The calculated values reveal that more than 70% of samples contain bioavailable zinc exceeding ten times the background level. The corresponding values at El-Kola are also enhanced but at less frequency; the CEF values surpass 10 in only 17% of samples. The maximum CEF value is consistent at the two sites (equal to 193 for both). Such enlarged levels of the bioavailable zinc indicate that the major part of the anthropogenic zinc is found in readily mobile forms.

The maximum value of the available lead recorded at El-Kola is 14.1 ppm,

whereas the equivalent value reported at El-Dair is 9.2 ppm. The CEF values of the bioavailable lead (Table 26) are significantly lower than the corresponding values of its total content, at the two sites; the matter that reflects the chemical immobility of lead.


170

In spite of the considerable total level of copper in the lands applied for

wastewater disposal, its bioavailable content is generally depleted. This level is very close to that of the wadi deposits and it is fluctuating around 1 ppm in most samples; minor exception is recorded. Such depleted level of the bioavailable copper is confirmed by the very low values of CEF (Table 26). The general lower content of the bioavailable copper is virtually ascribed to its incorporation in the organic fraction to be less available (see Jones and Turki, 1997; Li et al., 2000; Omer, 2003a). Copper could easily form complexes with organic matter due to the high stability constant of organic-Cu compounds (Li and Thornton, 2001).

A wide range of nickel concentrations is observed in the lands applied for

wastewater disposal, particularly at El-Kola; with some samples displaying significantly elevated levels (up to 34.6 ppm).

Lands applied for wastewater disposal at both El-Dair and El-Kola sites

show occasional enhanced concentrations of bioavailable Co, Cd and Cr as indicated from the CEF values (Table 26). The highest recorded values of CEF at El-Dair site are 3.6, 17.2 and 2.5, respectively. The equivalent values at El-Kola are 3.7, 4.7 and 3.9, respectively. Such behavior indicates the effect of organic matter on mobilizing these metals from their bearing mineral phases.


171

Table (26): The culture enrichment factor (CEF) of the bioavailable metal content for soil samples from lands applied for wastewater disposal.

El-Kola El-Dair ID Co Ni Cr Pb Zn Cu Cd ID Co Ni Cr Pb Zn Cu Cd

34 0.6 0.6 1.3 0.3 0.5 0.7 0.7 94 0.8 2.1 2.5 9.6 36.1 3.1 1.8 35 0.9 0.7 0.7 1.3 0.8 0.7 1.3 95 0.5 0.4 0.8 0.7 4.7 0.4 0.8 36 1.6 1.6 1.7 2.0 2.4 0.9 2.4 96 0.5 0.4 1.0 1.4 10.4 0.8 0.8 37 1.4 0.9 0.8 1.1 2.2 1.5 1.1 97 1.1 1.6 1.4 2.5 88.9 0.9 0.8 38 1.2 0.7 0.6 1.4 1.7 1.5 1.1 98 0.5 0.6 1.1 1.1 20.0 0.7 0.8 39 1.2 0.6 0.8 1.2 1.8 8.1 1.1 127 0.5 0.4 0.6 0.6 9.3 0.3 0.6 40 1.2 0.8 0.7 0.9 1.4 3.5 1.0 128 0.5 0.7 0.5 0.4 1.6 0.2 0.5 41A 2.5 5.1 1.1 3.0 63.4 1.9 1.3 129 1.6 4.0 0.5 1.7 94.2 1.4 1.8 41B 2.2 4.5 1.3 4.7 168.7 2.4 1.6 130 1.0 2.5 0.9 0.9 9.6 0.2 0.9 42 2.2 2.7 0.7 3.1 254.5 1.5 1.8 131 1.7 6.5 1.0 2.1 92.3 1.6 6.7 43 1.7 1.0 0.4 1.1 2.6 1.2 1.0 134 0.8 1.8 0.7 2.4 103.3 1.5 0.8 44 1.2 1.1 0.4 0.7 1.2 0.3 1.1 135 3.6 7.1 0.3 0.9 5.9 0.2 1.6 45 1.5 1.5 0.9 1.7 0.7 0.2 2.2 136 0.8 1.0 0.3 0.9 16.7 0.2 9.8 46 1.1 0.9 0.7 0.6 0.4 0.0 0.9 137 0.9 1.3 0.8 6.6 193.7 3.2 1.2 47 0.3 1.9 1.1 1.6 3.1 1.3 1.3

Was

tew

ater

f

arm

land

s

138 2.3 8.7 1.5 4.5 61.2 0.6 17.2 48 1.4 1.4 0.8 1.4 1.2 0.6 1.6 89 1.0 1.1 1.1 0.7 2.8 0.3 0.9 49 3.3 4.1 3.9 3.4 1.4 1.0 4.7 90 0.5 0.7 0.8 1.8 16.4 0.7 0.8 50 1.7 2.0 1.4 1.7 1.2 1.0 2.0 91 0.6 0.8 0.2 2.6 26.7 0.8 0.8 51 0.8 1.1 0.3 0.6 0.6 0.1 1.2 92 0.8 1.1 0.9 5.1 37.3 2.7 1.2 53 2.9 1.6 0.7 2.3 3.3 2.7 1.8 93 1.7 5.0 1.1 1.6 52.3 1.1 1.8 80 0.7 0.8 0.3 0.8 0.6 0.1 0.9 99 2.0 1.7 0.5 1.7 15.5 2.0 0.9 82 2.0 1.6 0.2 2.0 2.7 1.3 1.8 100 2.2 1.9 0.2 2.6 23.9 1.7 1.2

140 3.7 55.9 1.9 0.9 3.7 0.1 1.3 119 1.2 2.1 1.9 2.3 461.6 0.5 1.1 141 3.0 72.1 0.8 1.3 3.3 0.1 1.4 120 0.7 1.5 1.3 1.3 24.4 0.6 1.0 142 2.1 28.0 1.3 14.7 118.4 1.1 1.8 121 1.1 2.1 1.3 3.0 24.4 0.4 0.8 143 3.5 71.3 1.0 1.1 8.5 0.1 1.6 122 1.5 4.5 1.5 0.7 4.6 0.4 1.2 144 2.0 9.9 0.8 8.7 53.4 1.0 2.0 123 0.6 1.6 2.1 1.6 36.4 1.0 0.5 145 2.3 12.0 1.8 10.6 40.8 1.0 2.4 126 0.6 1.2 0.6 1.7 131.9 0.2 0.8

139 3.3 11.9 2.0 2.1 162.5 0.4 2.3

Was

tew

ater

pon

ds a

nd w

etla

nds

Was

tew

ater

p

onds

155 3.1 9.5 2.3 1.5 4.3 0.2 2.0


172

0

40

80

120

160

200

240

280

26 33 00 N26 32 00 N

31 36 00 E31 36 00 E

26 34 00 N

31 36 00 E

26 33 00 N26 32 00 N 26 34 00 N

31 36

00 E

31 36

00 E

31 36

00 E

0 0.50.5Kilometer

ppm

Pb

100

300

500

700

900

1100

26 33 00 N26 32 00 N

31 36 00 E31 36 00 E

26 34 00 N

31 36 00 E

26 33 00 N26 32 00 N 26 34 00 N

31 36

00 E

31 36

00 E

31 36

00 E

0 0.50.5Kilometer

ppm

Zn

Fig. (67): Geochemical maps showing the spatial distribution of the total heavy metal

content (ppm) at El-Dair wastewater disposal site.


173

30

50

70

90

110

130

150

170

190

26 33 00 N26 32 00 N

31 36 00 E31 36 00 E

26 34 00 N

31 36 00 E

26 33 00 N26 32 00 N 26 34 00 N

31 36

00 E

31 36

00 E

31 36

00 E

0 0.50.5Kilometer

ppm

Cu

35

45

55

65

26 33 00 N26 32 00 N

31 36 00 E31 36 00 E

26 34 00 N

31 36 00 E

26 33 00 N26 32 00 N 26 34 00 N

31 36

00 E

31 36

00 E

31 36

00 E

0 0.50.5Kilometer

ppm

Ni

Fig. (67): (Cont.).


174

100

110

130

150

170

190

210

26 33 00 N26 32 00 N

31 36 00 E31 36 00 E

26 34 00 N

31 36 00 E

26 33 00 N26 32 00 N 26 34 00 N

31 36

00 E

31 36

00 E

31 36

00 E

0 0.50.5Kilometer

ppm

Cr

10

15

20

25

30

35

40

26 33 00 N26 32 00 N

31 36 00 E31 36 00 E

26 34 00 N

31 36 00 E

26 33 00 N26 32 00 N 26 34 00 N

31 36

00 E

31 36

00 E

31 36

00 E

0 0.50.5Kilometer

ppm

Co

Fig. (67): (Cont.).


175

0.6

0.8

1

1.2

1.4

26 33 00 N26 32 00 N

31 36 00 E31 36 00 E

26 34 00 N

31 36 00 E

26 33 00 N26 32 00 N 26 34 00 N

31 36

00 E

31 36

00 E

31 36

00 E

0 0.50.5Kilometer

ppm

Cd

Fig. (67): (Cont.).


176

5

25

45

65

85

105

125

145

165

26 3

3 00

N26

32

00 N

31 49 00 E31 48 00 E 31 50 00 E

26 3

3 00

N26

32

00 N0 0.50.5

Kilometer

ppm

31 49 00 E31 48 00 E 31 50 00 E

Pb

75

175

275

375

475

575

675

26 3

3 00

N26

32

00 N

31 49 00 E31 48 00 E 31 50 00 E

26 3

3 00

N26

32

00 N0 0.50.5

Kilometer

ppm

31 49 00 E31 48 00 E 31 50 00 E

Zn

10

50

90

130

170

210

250

290

330

26 3

3 00

N26

32

00 N

31 49 00 E31 48 00 E 31 50 00 E

26 3

3 00

N26

32

00 N0 0.50.5

Kilometer

ppm

31 49 00 E31 48 00 E 31 50 00 E

Cu

Fig. (68): Geochemical maps showing the spatial distribution of the total heavy metal

content (ppm) at El-Kola.


177

35

45

55

65

75

85

95

105

115

26 3

3 00

N26

32

00 N

31 49 00 E31 48 00 E 31 50 00 E

26 3

3 00

N26

32

00 N0 0.50.5

Kilometer

ppm

31 49 00 E31 48 00 E 31 50 00 E

Ni

105

130

155

180

205

230

255

280

26 3

3 00

N26

32

00 N

31 49 00 E31 48 00 E 31 50 00 E

26 3

3 00

N26

32

00 N0 0.50.5

Kilometer

ppm

31 49 00 E31 48 00 E 31 50 00 E

Cr

25

30

35

40

45

50

26 3

3 00

N26

32

00 N

31 49 00 E31 48 00 E 31 50 00 E

26 3

3 00

N26

32

00 N0 0.50.5

Kilometer

ppm

31 49 00 E31 48 00 E 31 50 00 E

Co

Fig. (68): (Cont.).


178

0.9

1.1

1.3

1.5

1.7

1.9

26 3

3 00

N26

32

00 N

31 49 00 E31 48 00 E 31 50 00 E

26 3

3 00

N26

32

00 N0 0.50.5

Kilometer

ppm

31 49 00 E31 48 00 E 31 50 00 E

Cd

Fig. (68): (Cont.).


179

0

1

2

3

4

5

6

26 33 00 N26 32 00 N

31 36 00 E31 36 00 E

26 34 00 N

31 36 00 E

26 33 00 N26 32 00 N 26 34 00 N

31 36

00 E

31 36

00 E

31 36

00 E

0 0.50.5Kilometer

ppm

Pb

2

12

22

32

42

52

62

72

26 33 00 N26 32 00 N

31 36 00 E31 36 00 E

26 34 00 N

31 36 00 E

26 33 00 N26 32 00 N 26 34 00 N

31 36

00 E

31 36

00 E

31 36

00 E

0 0.50.5Kilometer

ppm

Zn

Fig. (69): Geochemical maps showing the spatial distribution of the bioavailable heavy

metal content (ppm) at El-Dair.


180

0.5

1

1.5

2

2.5

3

3.5

4

26 33 00 N26 32 00 N

31 36 00 E31 36 00 E

26 34 00 N

31 36 00 E

26 33 00 N26 32 00 N 26 34 00 N

31 36

00 E

31 36

00 E

31 36

00 E

0 0.50.5Kilometer

ppm

Cu

0.5

1.5

2.5

3.5

4.5

26 33 00 N26 32 00 N

31 36 00 E31 36 00 E

26 34 00 N

31 36 00 E

26 33 00 N26 32 00 N 26 34 00 N

31 36

00 E

31 36

00 E

31 36

00 E

0 0.50.5Kilometer

ppm

Ni

Fig. (69): (Cont.).


181

0.03

0.05

0.07

0.09

0.11

0.13

0.15

0.17

0.19

0.21

26 33 00 N26 32 00 N

31 36 00 E31 36 00 E

26 34 00 N

31 36 00 E

26 33 00 N26 32 00 N 26 34 00 N

31 36

00 E

31 36

00 E

31 36

00 E

0 0.50.5Kilometer

ppm

Cr

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

26 33 00 N26 32 00 N

31 36 00 E31 36 00 E

26 34 00 N

31 36 00 E

26 33 00 N26 32 00 N 26 34 00 N

31 36

00 E

31 36

00 E

31 36

00 E

0 0.50.5Kilometer

ppm

Co

Fig. (69): (Cont.).


182

0.05

0.1

0.15

0.2

0.25

0.3

26 33 00 N26 32 00 N

31 36 00 E31 36 00 E

26 34 00 N

31 36 00 E

26 33 00 N26 32 00 N 26 34 00 N

31 36

00 E

31 36

00 E

31 36

00 E

0 0.50.5Kilometer

ppm

Cd

Fig. (69): (Cont.).


183

0.5

2

3.5

5

6.5

8

9.5

11

12.5

26 3

3 00

N26

32

00 N

31 49 00 E31 48 00 E 31 50 00 E

26 3

3 00

N26

32

00 N0 0.50.5

Kilometer

ppm

31 49 00 E31 48 00 E 31 50 00 E

Pb

1

4

15

30

45

60

75

90

26 3

3 00

N26

32

00 N

31 49 00 E31 48 00 E 31 50 00 E

26 3

3 00

N26

32

00 N0 0.50.5

Kilometer

ppm

31 49 00 E31 48 00 E 31 50 00 E

Zn

0.5

1.5

2.5

3.5

4.5

5.5

6.5

26 3

3 00

N26

32

00 N

31 49 00 E31 48 00 E 31 50 00 E

26 3

3 00

N26

32

00 N0 0.50.5

Kilometer

ppm

31 49 00 E31 48 00 E 31 50 00 E

Cu

Fig. (70): Geochemical maps showing the spatial distribution of the bioavailable heavy

metal content (ppm) at El-Kola.


184

1

5

9

13

17

21

25

29

33

26 3

3 00

N26

32

00 N

31 49 00 E31 48 00 E 31 50 00 E

26 3

3 00

N26

32

00 N0 0.50.5

Kilometer

ppm

31 49 00 E31 48 00 E 31 50 00 E

Ni

0.05

0.15

0.25

0.35

26 3

3 00

N26

32

00 N

31 49 00 E31 48 00 E 31 50 00 E

26 3

3 00

N26

32

00 N0 0.50.5

Kilometer

ppm

31 49 00 E31 48 00 E 31 50 00 E

Cr

0.4

0.8

1.2

1.6

2

26 3

3 00

N26

32

00 N

31 49 00 E31 48 00 E 31 50 00 E

26 3

3 00

N26

32

00 N0 0.50.5

Kilometer

ppm

31 49 00 E31 48 00 E 31 50 00 E

Co

Fig. (70): (Cont.).


185

0.05

0.1

0.15

0.2

0.25

0.3

26 3

3 00

N26

32

00 N

31 49 00 E31 48 00 E 31 50 00 E

26 3

3 00

N26

32

00 N0 0.50.5

Kilometer

ppm

31 49 00 E31 48 00 E 31 50 00 E

Cd

Fig. (70): (Cont.).


186

6.3.2 Groundwater 6.3.2.1 Salinity, ammonia and nitrate

Results of the chemical analysis of ten groundwater samples (8 from El-Dair and 2 from El-Kola) are given in table (27); values of TDS, ammonia and nitrate together with the maximum allowable limit are graphically displayed in figure (71). The total dissolved salts (TDS) in the groundwater samples from El-Dair show insignificant variability, being range from 732 to 909 mg/l. The level which is consistent with the general range reported along the western side of the Nile Valley under similar geologic and hydrogeologic conditions (cf. Omer and Abdel Moneim, 2001). This behavior reveals that the wastewater disposal at El-Dair site has no important effect on the groundwater salinity. On the other side, the total dissolved salts in groundwater samples from El-Kola (5568 and 3328 mg/l) are extremely higher than those from El-Dair and, moreover, significantly higher than those from locations immediately outside the disposal site under similar conditions. So, it is clear that the wastewater disposal at El-Kola played a major role in increasing the groundwater salinity. The wastewater itself possesses extremely lower salinity but the percolating wastewater leaches great quantities of soluble salts from the underlying marine Pliocene clays, among the water circulation and sediment-water interaction, containing substantial salt content (Omer and Abdel Moneim, op. cit).

Although nitrate contamination of water can result from several natural

and human activity-related sources, the on-site wastewater disposal is considered to be a significant contributor (cf. ACES, 1995). Most of the nitrogen in excrete derives from the urine. The nitrogen forms in urine are highly soluble, and when mixed with water they are not easily liberated. Therefore, the major part of nitrogen will remain in wastewater. Once the conditions become anaerobic, the organic nitrogen is converted to ammonium (NHB4PB

+P) which is the most common

nitrogen form reaching the wastewater disposal sites. There, ammonium is subjected to the process of nitrification to be transformed to nitrite (NOB2PB

-P) and

then into nitrate (NOB3PB

-P). The relative abundance of NOB3PB

-P and NHB4PB

+P is controlled


187

by many biological and chemical transformations, such as nitrification and denitrification. Nitrate is highly soluble in water and poorly retained in the soil; it can be thus transported long distances through the soil to reach the water sources. The leaching potential of NOB3PB

-P within the soil system depends on many

factors, of which the soil texture is most important (Smith and Cassel, 1991). With respect to the investigated groundwater samples (from wells and

hand pumps), contamination by nitrate has been documented in all samples. As many as 80% of the water samples contain nitrate concentrations exceeding the 45 mg/l standard for safe drinking water recommended by the United States Environmental Protection Agency (EPA). Eight of the examined ten samples display NOB3PB

-P ranging from 57 to 120 mg/l. The nitrate contents in the remainder

two samples (34 and 35 mg/l) are slightly lower than the standard limit. The average nitrate content in groundwater of El-Kola (mean=108 mg/l) is generally higher than that of El-Dair site (mean= 67 mg/l). Such contamination of water by nitrate, reaching up to more than two times higher than the permissible limit, is considered to be a serious environmental and public health concern, where various health risks and toxicity can arise.

Natural levels of ammonium (NHB4PB

+P) in ground and surface water are

usually very low. Higher concentrations can be used as well indicator of anthropogenic pollution including sewage and animal wastes (WHO, 1993). The estimated contents of NHB4PB

+P in groundwater samples of El-Dair show a wide

range of concentrations (0.43 to 7.25 mg/l), whereas they display a constricted range at El-Kola (4.3 to 6.7 mg/l). The average content at the latter site (mean= 5.5 mg/l) is significantly higher than that of the former one (mean= 0.93 mg/l).

The elevated contents of nitrate (NOB3PB

-P) in groundwater from both sites

should be of anthropogenic source, where no nitrate-bearing components are recorded in the subsurface fluviatile Nile basin sediments (see Omer, 1996). The reported concentrations of NHB4PB

+P are extremely higher than the naturally


188

documented levels; it is thus most probably of anthropogenic parentage. The contemporaneous enhancement of NOB3PB

-P and NHB4PB

+P in groundwater from the

two sites confirms this conclusion. The general higher concentrations of NHB4PB

+P

and NOB3PB

-P at El-Kola, despite the very short period of waste disposal, reflect the

shallow depth of the pumped water. Worthwhile to mention that, the augmentation of nitrate and ammonium in groundwater is of concern not only because of their potential adverse effect, but also because they indicate the groundwater pollution and confirm reaching of wastewater to such vital water resource. Therefore, other chemical (organic and inorganic) and biological pollutants are strongly expected to be also present.

Table (27): Data of the chemical and bacteriological investigation of the groundwater

samples.

Heavy Metals (ppm) Site Sample pH EC µmohs

TDS mg/l Zn Pb Cu Co Ni

NHB4PB

+

mg/l NOB3PB

-

mg/l TC FC

X1 7.57 1350 864 0.044 0.089 0.004 0.057 0.083 0.76 62 0 0 X2 7.26 1420 909 0.035 0.086 0.007 0.050 0.064 2.90 34 150 70 X3 7.35 1330 851 0.031 0.045 0.000 0.039 0.063 0.43 57 0 0 D1 7.32 1129 723 0.037 0.087 0.011 0.052 0.065 0.61 105 9 2 D6 7.43 1240 794 0.051 0.072 0.012 0.047 0.052 0.55 82 2 0 D7 7.42 1250 800 0.048 0.067 0.009 0.042 0.061 0.70 67 0 0 D8 7.59 1280 819 0.039 0.082 0.008 0.055 0.039 7.25 97 70 18 D9 7.19 1200 768 0.042 0.079 0.011 0.039 0.058 0.83 35 40 9

El-D

ir

Mean 7.39 1275 816 0.040 0.030 0.010 0.050 0.060 1.75 67 34 13 Q1 7.81 8700 5568 0.045 0.021 0.010 0.016 0.025 6.70 120 600 240 Q2 7.65 5200 3328 0.036 0.019 0.008 0.014 0.019 4.30 96 450 160

El-K

ola

Mean 7.74 7400 4448 0.041 0.020 0.009 0.015 0.022 5.50 108 525 200

TC= total coliform, FC= faecal coliform (counts/100ml)


189

1 2 3 4 5 6 7 8 9 100

1

2

3

4

5

6

7

8

Sam ple No.

Am

mni

a (m

g/l)

0

20

40

60

80

100

120

140

Sam ple No.

Nitr

ate

(mg/

l)

Sam ples MALNitrate (m g/l)

Am onia (m g/l)

0

1,000

2,000

3,000

4,000

5,000

6,000

7,000

Sam ple No.

TDS

(mg/

l)

Sam ples MALTDS (m g/)

Fig. (71): The TDS, Nitrate (NOB3PB

-P) and Ammonia (NHB4PB

+P) in groundwater at El Dair (1-8)

and El Kola (9, 10). MAL= Maximum Allowable Limit.

Ammonia (mg/l)


190

6.3.2.2 Heavy metals

The estimated concentrations of heavy metals (Zn, Pb, Cu, Co and Ni) in the groundwater are generally low at the two sites. They do not exceed the permissible limits for drinking except for nickel that shows slightly higher level. Concentrations of zinc, lead and copper are strictly similar at the two sites, where no significant difference is observed. Cobalt and nickel, on the other hand, are relatively higher in the groundwater samples of El-Dair.

It is thus clear that, insignificant increase of heavy metals content is

recorded in the groundwater even in the wells immediately adjacent to the wastewater ponds. This indicates that only trace concentrations of heavy metals potentially reached the groundwater. So, the impact of wastewater disposal on the metals content of groundwater, at the investigated sites, is negligible. Accordingly, it is concluded that the major part of heavy metals is incorporated in the surface and shallow soil layers, as a result of their immobility, and that their downward migration to deeper zones is very limited. The abnormal accumulation of heavy metals in the surface soil layer proves this conclusion.

6.3.2.3 Bacteriology

Untreated, or improperly treated, wastewater contains biological contaminants that can cause wide range of diseases, ranging from simple troubles to lethal infections. These disease-causing microorganisms are known as pathogens. Five main categories of pathogens are recognized: bacteria, viruses, protozoas, fungi and worms. When wastewater is allowed to reach the water resources without adequate treatment, pathogens can cause deterioration of water quality to become unsafe for human use.

Coliform bacteria are a natural part of the microbiology of the intestinal

tract of warm-blooded mammals, including man. Large counts of coliform bacteria are therefore found in the wastewater. The use of coliform bacteria as an indicator of faecal pollution of water supplies is generally supplemented by the faecal coliform count (WHO, 1971; APHA, 1985). Faecal coliform is thus classified as good sewage indicator (Benson, 1994). The presence of coliform


191

bacteria, faecal coliform in particular, in groundwater is a primary indicator for possible penetration of wastewater into the aquifer and reveals the presence of disease causing organisms (Lemoni-Relis and Eren, 1994).

In the present study, counts of both the total and faecal coliform bacteria

have been determined to appraise the biological contamination of groundwater in the investigated sites (Table 27). It is obvious that groundwater of El-Kola site is evidently bacteriologically contaminated where the examined two samples display positive results of both the total and faecal coliform. Groundwater at El-Dair is partially contaminated since about 50% of the investigated samples give positive results. The higher content of total and faecal coliform at El-Kola is, again, due to the shallow depth of pumping.

The EPA Maximum Contaminant Level (MCL) for coliform bacteria in

drinking water is zero total coliform per 100 ml. The groundwater of El-Kola site and considerable number of wells (50%) at El-Dair contain total and faecal coliform bacteria surpassing this level (Fig. 72). It is that a strong evidence indicating microbiological contamination of the examined groundwater, where presence of various other pathogens is expected. The co-association of NHB4PB

+P,

NOB3PB

-P and coliform bacteria in groundwater at the two sites confirms the stated

adverse effect of the improperly disposed wastewater on the groundwater aquifer, and aggravates the problem of water quality.

Conclusively, the wastewater disposal practice at the currently operating

sites (El-Dair and El-Kola) has caused a cruicial contamination of soil by heavy metals; contamination of soil by other chemicals, either organic or inorganic is extremely probable. Moreover, the groundwater at these sites was critically affected by such practice, where chemical and bacteriological contamination was documented. In Sohag province, six other sites will be in use for wastewater disposal through the near future (Fig. 73). The same scenario is currently proceeding along most parts of the Nile Valley in Upper Egypt. Assuming an analogous contamination status of soil and water recourses at these sites and furthermore along the Nile Valley, a disastrous environmental problem will be arisen along the whole valley to cause unavoidable health troubles through the long term.


192

1 2 3 4 5 6 7 8 9 100

50

100

150

200

250

300

Sample No.

Cou

nts/

100

ml

0

100

200

300

400

500

600

700

Cou

nts/

100

ml

Total coliform

Faecal coliform

Fig. (72): The total and faecal coliform in groundwater at El Dair (1-8) and El Kola (9, 10).


193

Fig. (73): Map of Sohag area showing the wastewater disposal sites.

CHAPTER 7 CONCLUSION AND

RECOMMENDATIONS

CONCLUSION AND RECOMMENDATIONS

194

CHAPTER 7


7.1 Conclusion The present work is one of the very rare studies related to the critically

important field of environmental geochemistry. Environmental geochemistry is the scientific field dealing with studying the interaction between chemical elements throughout the various geoenvironmental media (e.g. rocks, soil and water), and quantify their direct or indirect impact on the biosystem in general and human health in particular. Heavy metal contamination of sediments, soil and water, from either natural or anthropogenic source, represents a major problem to be concerned by environmental geochemistry because of possible adverse effect on the human health. So, a brief background was given in the introductory chapter to illustrate the direct and tight relationship between geological materials and biosystem.

The study area represents an important segment from the Nile basin

covering the middle sector of Sohag province and extending between latitudes 26P

°P 24P

′P 16P

″P and 26P

°P 36P

′P 16P

″P, and bounded from both the east and west by the lower

Eocene cliffs. The current study deals with the geochemical characteristics of the surficial Nile basin sediments in the study area aiming to quantify their environmental relevance. The study is directed principally to discuss the distribution pattern and evaluate the background levels of total heavy metals and their bioavailability in the surficial sediments throughout the study area. In addition, quantification of behavior and interrelation between heavy metals and identifying their possible sources and environmental impact is a vital objective. However, nine metals (Fe, Mn, Co, Ni, Cr, Pb, Zn, Cu and Cd) were selected to be considered in the present study.

Reviewing the geologic setting of the study area and describing the most

important landuses, are the main subjects discussed in the second chapter.


195

The various rock units distributed in Sohag area are composed wholly of sedimentary succession ranging in age from lower Eocene to Recent. The following table summarizes the main units in the study area.

Age Formation

Wadi deposits Recent (Holocene) Alluvial deposits

(Nile floodplain) Dandara

Ghawanim Kom Ombo

Pleistocene

Qena Late Pliocene /

Early Pleistocene Issawia The

Neo

gene

and

Q

uate

rnar

y

Early Pliocene Muneiha Drunka Lower Eocene Thebes

The surficial sediments of the study area are differentiated in the present study into four main sectors of various landuses. These are:


The third chapter deals with the material and methods performed in the

present study including the sampling protocol and the various laboratory measurements. Two hundreds and twenty six samples were collected from the different surficial sediments throughout the study area covering the different landuses. The collected samples were subjected to the various physical and chemical investigations including:

• The textural characteristics, • The hydrogen ion concentration (pH), • The inorganic carbonate content (CaCOB3B), • The organic matter content (OM), and • The cation exchange capacity (CEC).


196

The fine fraction (<63µm) of the sediment samples was separated and chemically analyzed for the total heavy metals content (Fe, Mn, Co, Ni, Cr, Pb, Zn, Cu and Cd) after acid digestion (HF + HNOB3B + HClOB3B). The metal bioavailability (DTPA-extractable), which is defined as the metal availability to be taken into the biosystem was estimated in the bulk samples (<2mm). In addition, eight groundwater samples were collected from 8 El-Dair wastewater disposal site. Another two samples were collected from shallow hand pumps at El-Kola disposal site. The groundwater samples were chemically (TDS, NHB4PB

+P, NOB3PB

-P, Co, Cu, Ni, Pb and Zn) and bacteriologically

(total and faecal coliform) investigated. The physical and chemical properties of sediments are critically important

in studies of environmental geochemistry as they largely affect the behavior of heavy metals and their bioavailability. Hence, the physical and chemical properties of the studied sediments were discussed in the fourth chapter.

Regarding the textural characteristics, the major part of the cultivated

floodplain and the topsoil layer of the reclaimed lands are silty in nature where the silt fraction is prevailed. The subsoil layer of the reclaimed lands, the wadi deposits and the lands applied for wastewater disposal at El-Kola and El-Dair are mostly described as coarsely textured sediments, where sand is the predominant fraction. The wastewater disposal practice for a period of 15 years did not markedly affect the textural characteristics of sediments.

The pH values do not vary greatly throughout the studied sediments.

The measured pH values indicate that the Nile floodplain and the reclaimed lands are slightly alkaline to alkaline in nature. The pH values of wadi deposits are comparatively slightly higher. Although most samples at El-kola wastewater disposal site are slightly alkaline to alkaline, some samples tend to be slightly acidic. Sediments of the wastewater disposal site at El-Dair are frequently acidic (pH<7).


197

Sediments of the Nile floodplain show the least content, and less variable, of carbonate among the studied sediments; insignificant difference was reported through the topsoil and subsoil layers. The total carbonate content of the reclaimed lands is considerably higher than that of the cultivated floodplain and it is widely variable; a significantly elevated content was recorded in the subsoil layer. Wadi deposits possess the highest content of carbonate as affected by the disintegrated product of the lower Eocene limestone. It is clear that the carbonate content in the sites applied for wastewater disposal is negatively affected by such practice particularly in the topsoil layer. So, the carbonate content in these sites is relatively lower than the adjacent wadi deposits.

Sediments of the cultivated floodplain, reclaimed lands and wadi deposits

are very poor in their organic matter content with very minor exceptions reported very close to the lands applied for wastewater disposal. With respect to the sites applied for wastewater disposal, they have a wide range of organic matter content reflecting different grades of contamination with raw wastewater effluent. Samples with higher levels of organic matter are those characterized by elevated accumulation of biosolids at the wastewater dumps. Accumulation of organic matter is more pronounced in the topsoil layer. However, the organic matter content in the wastewater disposal site at El-Dair is markedly higher than that reported at El-Kola site reflecting the longer term of wastewater disposal.

In the studied sediments, values of the cation exchange capacity (CEC) are

mainly functioned by the clay mineral content of samples. The highest values of CEC are recorded in the cultivated floodplain whereas the wadi deposits show the lowest values reflecting the higher clay content in the former. The estimated values of CEC in the reclaimed lands are relatively less than those of the cultivated floodplain; this may be due to their higher content of carbonate and lower content of clay fraction. The CEC values are extremely fluctuated in the lands applied for wastewater disposal, reflecting the variable content of carbonate, clay minerals and organic matter.


198

The distributions pattern of the total heavy metals (Fe, Mn, Co, Ni, Cr, Pb, Zn, Cu and Cd) in the surficial sediments throughout the study area was discussed in chapter 5. Statistical analysis was performed to quantify the behavior of heavy metals and discuss their controlling factors.

The correlation coefficient was calculated for the estimated heavy metals,

carbonate, organic matter and clay content. Iron, cobalt nickel and manganese are significantly correlated and they are positively correlated with the clay fraction, whereas they are negatively correlated with carbonate. This implies that these metals are concentrated principally in the non-calcareous fine argillaceous fraction. Accordingly, they are more abundant in sediments of the Nile floodplain, whereas they are diluted in the carbonate-rich wadi deposits. Cadmium is very strongly correlated with carbonate; so, the highest cadmium content is recorded in the wadi deposits following their elevated carbonate content. Lead and zinc are positively correlated and they are directly interrelated with the organic matter content. On the other hand, they are negatively correlated with the clay content. So, lead and zinc are significantly associated in sediments rich in organic matter but they are diluted in the clay-rich sediments. Accordingly, the most abundant contents of lead and zinc are reported in the lands applied for wastewater disposal containing elevated levels of organic matter. Although, chromium displays indiscernible correlation with the clay content, it is positively correlated with iron, nickel and cobalt. Chromium is negatively correlated with the carbonate content suggesting its co-association with the mentioned metals in the non-calcareous fraction.

The anomalous levels (outliers and extremes) of heavy metals were

statistically determined in the examined sediments throughout the study area. It is obvious that lead, zinc and copper display the most frequent anomaly, and most of the anomalous levels are found in the lands applied for wastewater disposal at El-Kola and El-Dair sites. This implies that the wastewater disposal playan important role in accumulating these metals. Chromium, cadmium, manganese and nickel display less frequent anomaly and the anomalous values


199

are irregularly distributed throughout the different landuses. This suggests that the influence of anthropogenic activities on the behavior of these metals is limited. Iron displays abnormal levels at only two sites that show no anomaly for lead, zinc or copper. This reflects the natural behavior of iron as controlled by the lithological characteristics of sediments and suggests that the elevated levels of iron are either naturally occurring following abnormal accumulation of iron-rich phases or due to independent addition related to unknown practice. No anomalous levels of cobalt were recorded throughout the study area, reflecting its natural behavior and suggesting no anthropogenic accumulation in the examined sediments.

The inter-variable relationship and the possible factors controlling the

heavy metal behavior were statistically quantified using the R-mode factor analysis. Loadings of the 1P

stP and 2P

ndP factors are powerful and they differentiated

the considerable variables into four distinctive geochemical trends reflecting their possible associated sources:

• Clay trend (geogenic), • Carbonate trend (geogenic), • Organic matter trend (anthropogenic), and • Mixed trend.

Clay, iron and cobalt are tightly associated forming the pronounced clay

trend. This association is most probably of natural geogenic source (i.e. they are lithogenically controlled) and it corresponds to uncontaminated clay-rich sediments. The most interesting association is the carbonate trend including carbonate and cadmium and suggesting that carbonate is the most important form of cadmium in the investigated sediments. The organic matter trend includes the organic matter, lead and zinc. The severe association of lead and zinc with the organic matter and their reverse behavior relative to those of natural geogenic source suggest that they are almost certainly affected by anthropogenic contribution. Manganese, nickel, chromium and copper form one related association. This trend is intermediate between the clay trend and organic matter


200

trend indicating that the behavior of these metals is affected by both the geogenic characteristics of sediments and the anthropogenic supply (i.e. mixed trend). The behavior of chromium, manganese and nickel is considerably affected by the lithogenic characteristics of sediments while the anthropogenic supply is occasional. On the contrary, copper is significantly influenced by the anthropogenic supply.

In addition, the inter-sample relationship was statistically evaluated using

the Q-mode factor analysis. The examined samples representing the study area were distinctively loaded on the stated geochemical trends. So, the main factors controlling the levels and distribution pattern of the estimated metals were quantified. Also, the natural composition and anthropogenic activities influencing the behavior of these metals were determined. Almost all samples of the cultivated floodplain and topsoil layer of the reclaimed lands are loaded on the clay trend. Most samples of the subsoil layer of the reclaimed lands are included in the carbonate trend reflecting their calcareous nature; some samples are loaded on the clay trend reflecting the interaction with the overlying topsoil layer. All the examined samples of wadi deposits are loaded on the carbonate trend following their calcareous nature and indicating that the compositional characteristics of wadi deposits are naturally controlled where no anthropogenic supply is observed. The majority of samples from the wastewater disposal site at El-Dair are distributed between the organic matter trend and the calcareous trend reflecting the natural calcareous composition of sediments and the addition of biosolids related to the raw wastewater disposal. Sediments of the wastewater disposal site at El-Kola are extremely scattered throughout the different variable trends, indicating diverse compositional behavior as controlled by the natural lithological characteristics of sediments and the anthropogenic impact related to raw wastewater disposal. The lithology of these sediments is extremely complicated reflecting variable mixture of calcareous and siliciclastic materials.

The bioavailable metals fraction of manganese, cobalt, chromium and

cadmium is generally low in sediments of the Nile floodplain, reclaimed lands


201

and wadi deposits, indicating that the major part of these metals is firmly incorporated in the crystal lattice of their bearing mineral phases. The bioavailable level of these metals in the lands applied for wastewater disposal is strictly similar to that of the nearby wadi deposits implying that the wastewater disposal practice has no important influence on the bioavailability of these metals.

Sediments of the floodplain, reclaimed lands and wadi deposits display

depleted concentration of the bioavailable iron, indicating that it is tightly held in the crystal lattice of the iron-bearing mineral phases particularly the ferromagnesian minerals and iron oxide. Extremely elevated level of bioavailable iron was reported at only two sites, which are affected by the wastewater disposal practice. Regarding the lands applied for wastewater disposal, abnormally elevated levels of bioavailable iron were frequently recorded indicating that a considerable mobile fraction of iron is carried by the wastewater. The bioavailable content of zinc and lead is usually low in sediments of the floodplain, reclaimed lands and wadi deposits, with some exception, reflecting their incorporation in their bearing mineral phases. Contrarily, extremely elevated concentration of the bioavailable fraction of zinc and lead was frequently found in the lands applied for wastewater disposal indicating their anthropogenic source. Although the relatively low content of the bioavailable copper in sediments of the floodplain, reclaimed lands and wadi deposits, it is more depleted in the lands applied for wastewater disposal reflecting its fixation in the form of organic compounds.

The sixth chapter was destined to discuss the assessment of environmental

consequences. Two main objectives were considered: 1) determination of the background levels of heavy metals in the uncontaminated sediments, and 2) quantification of the environmental consequences of the anthropogenic activities particularly the improper wastewater disposal.


202

The natural background levels of heavy metals in surficial sediments of the study area are urgent to:

• determine the accepted range of metals for the uncontaminated sediments, • determine if contamination exists, • detect the sites of contamination, • measure the contamination intensity, and • reveal and follow up changes in contamination state with time.

The accepted range of natural background levels of heavy metals for the uncontaminated sediments of the cultivated floodplain, reclaimed lands and wadi deposits were statistically calculated to meet the median plus or minus twice the standard deviation of the distribution after excluding the anomalous values (outliers and extremes). Values considerably greater than the tabulated background range are indicative of metal contamination. The extent of sediment contamination by heavy metals was quantified compared with the maximum Allowable limit (MAL) reported for the worldwide soils.

Sediments of the cultivated floodplain, reclaimed lands and wadi deposits

of the study area have perfect background values of the estimated heavy metals, where they rarely exceed the maximum allowable limit (MAL). Only few samples belonging to these sediments show abnormal levels of some metals as governed by either natural or anthropogenic practice.

However, two sites (El-Kola and El-Dair) are currently used for the

wastewater disposal; the wastewater is improperly disposed of causing disastrous environmental impact. The environmental consequences of the wastewater disposal were discussed and quantified; a special attention was given to the contamination status of soil and groundwater at these two sites.

The lands applied for wastewater disposal at El-Dair and el-Kola display

potentially elevated concentrations of zinc, lead and copper compared with the corresponding wadi deposits. This implies that a significant fraction of these metals is loaded by the wastewater and the associated biosolids.


203

The concentrations of these metals are frequently exceeding the maximum allowable limit (MAL) indicating marked grade of contamination. Chromium and nickel are occasionally surpassing the MAL. Elevated levels of the bioavailable fraction of zinc and lead were reported in these sites and having a good chance to reach the food chain and biosystem directly or indirectly. So, contamination of soil by heavy metals in the lands applied for wastewater disposal is confirmed and still going on to represent a crucial environmental problem.

On the other hand, the improper wastewater disposal at the mentioned sites

has a potential chance to cause contamination of the nearby surface water resources and the underneath groundwater. The study showed that the groundwater at the two sites is critically contaminated, chemically and bacteriologically. Contamination by nitrate (NOB3PB

-P) has been documented in all the

investigated groundwater samples. As many as 80% of the water samples contain nitrate concentrations exceeding the standard limit for safe drinking water. Elevated concentrations of ammonium (NHB4PB

+P), which is indicative for

anthropogenic pollution including sewage waste, were frequently recorded in the groundwater from these sites. The presence of faecal coliform bacteria, which is classified as good sewage indicator, in groundwater is a primary clue for possible penetration of wastewater into the aquifer. The study showed that all groundwater samples from El-Kola and 50% of those from El-Dair wastewater disposal sites have positive results of the faecal coliform. It is thus a strong evidence implying microbiological contamination of the groundwater in the concerned sites, where presence of various other pathogens is most probable. The augmentation of nitrate and ammonia in groundwater is of concern not only because of their potential health effect, but also because they indicate the groundwater pollution and confirm reaching of wastewater to such important water resource; so, other chemicals, either organic or inorganic, are strongly expected to be included. The co-association of nitrate, ammonia and coliform bacteria in groundwater at the two sites confirms the adverse impact of the improperly disposed wastewater on the groundwater aquifer and supports aggravating the problem of water quality. In Sohag province, six other sites will be in use for wastewater disposal through the near future. Assuming an analogous contamination status of soil and water recourses at these sites and furthermore along the Nile valley, a disastrous environmental problem will be arisen along the whole valley.


204

7.2 Recommendationds

1- The environmentally releavent metals need to be estimated in the surficial sediments along the whole Nile Valley and Delta.

2- Special attention should be paid to sites ready to be contaminated by anthropogenic activities as industrization, urbanization, traffic emission, agricultural and wastewater disposal practice.

3- Detailed geochemical maps should be constructed for the various metals along the Nile Valley and Delta. Accordingly, the different hot spots displaying anomalous levels of certain metals will be known. Then, appropriate regulations and arrangements should be taken to control and mitigate the adverse health effect of the different contaminants.

4- Detailed chemical investigation of water resources (surface and groundwater) along the Nile Valley and Delta is urgent. A valuable database will be available to help in detecting and controlling contamination sources.

5- The interrelation between the heavy metal levels in the geoenvironmental media (sediments, soil and water resources) and the widespread environmental diseases need to be quantified.

6- Regarding the wastewater disposal sites, the following recommendations need to be achieved:

• The spread of waterborne diseases resulting from groundwater contamination should be surveyed and quantified in the areas surrounding the wastewater disposal sites

• Stringent controls should be taken to prevent farmers from irrigation by raw wastewater; restrictions on type of crops should be also considered.

• The improper wastewater disposal into the ponds should be urgently ceased until they dry up.

• The irrigation system of wastewater farmlands must be changed from flooding to spray or drop irrigation to minimize the chance of wastewater percolation into the groundwater.

• Sites newly planned for wastewater disposal must be geoscientifically investigated in order to evaluate their suitability for this purpose.

205

REFERENCES

REFERENCES

205

REFERENCES Abdel-Aal, R.M. (1961): Pedogenic studies on a farm at Mostorod. M.Sc. Thesis, Fac.

Agric., Cairo Univ., Egypt. Abd El-Aziz, S.H. (1998): Pedological studies on some soils of wadi El-Assiuti, Assiut,

Egypt. Ph.D. Thesis, Fac. Agric., Assiut Univ., Egypt. Abd El-Aziz, S.H. and Ghallab, A. (2002): Land classification, evaluation and use of

some soils in Atmur El-Nuqra valley, Kom Ombo, Aswan, Egypt. Assiut J. Agric. Sci. V.33, No.2, pp.221-239.

Abdel-Fattah, K.S. (1963): Morphological and chemical studies on the soils of the Middle part of the Nile Delta. M.Sc. Thesis, Fac. Agric., Ain Shams Univ., Egypt.

Abd El-Maksoud, M.M.R.; Abdel-Nabi, A.O.; Zaki, H.K. and Salem, M.Z. (2000): Using of field morphological rating system to estimate the development of wadi Qena soils. Mansoura J. Agric. Sci., V.25, No.3, pp.1845-1864.

Abd El-Naim, E.M.; Ibrahim, A.E. and El-Shal, M.E. (1982): A preliminary study on the effect of using sewage water in sandy soils. Fac. Agric., Ain Shams Univ. Research Bull.

Abd El-Razek, M. (1969): Studies of some minor elements status in Assiut soil and crops. M. Sc. Thesis, Assiut Univ. Egypt.

Abd El-Razek, M.; Ghoneim, M.F.; El-Gharably, G.A. and Abd Ellah, K. (1984a): Micronutrients status in soils of Upper Egypt. 3-Iron. Assiut J. Agric. Sci, V.15, pp.39-50.

Abd El-Razek, M.; Ghoneim, M.F.; El-Gharably, G.A. and Abd Ellah, K. (1984b): Micronutrients status in soils of Upper Egypt. 4-Manganese. Assiut J. Agric. Sci, V.15, pp.51-60.

Abdel Kader, F.H. and Abu Ghalwa, S.I.M. (1973): Distribution of total and free iron forms in different soils of Egypt. Alex. J. Agric. Res. V.3, pp.443-449.

Abdel-Shakour, E.A. (1982): Physiological studies on the contamination and toxicity of some plants by certain heavy metals. Ph.D. Thesis, Fac. Agric., Cairo Univ., Egypt.

Abou El-Khir, A.M. (2000): Some soil properties and trace elements as influenced by some biochemical activities in the eastern Nile Delta soils. J. Agric. Sci. Mansura Univ., V.25, No.1, pp.8421-8438.

Abou Hussien, E.A. and El-Koumey, B.Y. (1997): Influence of wastewater on some soils and plant in Menofiya Governorate. Menofiya J. Agric. Res. V.22, No.6, pp.1733-1748.

Aboulroos, S.A. and Abdel-Wahid, M.A. (1978): Evaluation of two methods of measuring available soil copper. Beitrage Type. Lardwirtsch. Veterinar Med., V.16, pp.155-162.

Aboulroos, S.A.; Holah, Sh.Sh. and Badawy, S.H. (1989): Influence of prolonged use of sewage effluent in irrigation on heavy metal accumulation in soils and plants. Z. Pflanzenearnahr. Bodenken., V.152, pp.51-55.

Aboulroos, S.A.; Holah, Sh.Sh. and Badawy, S.H. (1996): Background levels of some heavy metals in soils of Egypt and associated corn plant. Egypt. J. Soil Sci. V.36, No.1-4.

Abou Yuossef, M.F. (1999): Diagnostic study on certain heavy metals in the soils located at the western bank of Suez Canal. Zagazig J. Agric. Res. V.26, No.4, pp.1191-1212.

REFERENCES

206

ADEME and RECYVAL (2001): Compost de boues de stations d’épuration municipales : qualité performances agronomiques et utilizations.

Adriano, D.C. (1986): Trace elements in the terrestrial environment. Springer-Verlag, New York.

Alabama Cooperative Extension Service (ACES) (1995): Water quality: Typical contaminants and problems (nitrate). Auburn University, wq-239.al.

Alaily, F. (1979): Changes in phosphorus content in soil during irrigation with sewage effluent. Mitteilungen der Deutschen Bodenkundlichen Geselleschaft., V.29, pp.917-920.

Alderton, D.H.M. (1985): Sediments. In: MARC Report 31, Historical Monitoring, University of London, pp.1-95.

Allen, S.E. (1989): Chemical analysis of ecological materials. 2P

ndP Ed. Blackwell Sci.

Publ., Oxford. Alloway, B.J. (1990): Cadmium. In: Alloway, B.J. (Ed.). Heavy metals in soils. John

Wiley and Sons Inc., New York, pp.100-124. Alloway, B.J.; Tills A.R. and Morgan, H. (1985): Trace substances in environmental

health., V.18, pp.187-201. Almond, H. (1955): Determination of traces of cobalt in soils. Anal. Chem., V.25,

pp.166-167. Amer, A.F.; Krintsov, M.L. and Hanna, F.L. (1970): The Egyptian carbonate rocks

and the possibilities of their utilization. In: studies on some mineral deposits of Egypt. Geol. Surv. Egypt, pp.195-208.

American Public Health Association (APHA), (1985): Standard methods for the examination of water and wastewater. 16P

thP edition, Washington, D.C. 445p.

Amira, M.S. (1997): Effect of long term irrigation with polluted water on morphological, micromoropholigical and chemical properties of some soils of the Nile Delta, Menofiya. J. Agric. Res., V.22, No.6, pp.1749-1765.

Amira, M.S. and Ibrahim, M.A.M. (2000): Pedology, clay mineralogy and classifications of some soils representing the western desert fringes of the Nile valley in middle Egypt. Minufia J. Agric. Res., V.25, No.1, pp.217-235.

Appleton, J.D.; Fuge, R. and McCall, G.J.H. (1996): Environmental geochemistry and health with special reference to developing countries. Geological Society Special Publication No.113.

Aragnَ, P.A.; Torres, V.G.; Monroy, F.M.; Luszczeewski, K.A. and Leyva, R.R. (2000): Scanning electron microscope and statistical analysis of suspended heavy metal particles in San Luis Potos, Mexico. Atmos. Environ., V.34, pp.4103–4112.

Attia, K.K. (1988): Studies on certain micronutrients in the soils of Aswan and El-Minia Governorates. M.Sc. Thesis, Fac. Agric. Assiut Univ.

Aubert, H. and Pinta, M. (1977): Trace elements in soils. Elseiver, Amsterdam. Badawy, S.H. and Helal, M.I.D. (1997): Impacts of heavy metals of sewage effluent

on soils and plants of Helwan area. J. Agric. Sci. Mansoura Univ., V.22, No.12, pp.4737-4754.

Baker, D.E. and Chesnin, L. (1975): Chemical monitoring of soils for environmental quality and animal and human health. Advan. Agron., V.27, pp.306-374.

Ball, J. (1939): Contributions to the geography of Egypt. Survey & Mines Dept., Cairo, 308p.

REFERENCES

207

Bayoumi, N.A.; El-Wakeel, A.E.; Kerlous, R.G. and Rehan, M.G. (1993): Waters of low quality and cultivation in a sandy soil: I. Effects on soil properties and drainage water composition. Menofiya. J. Agric. Res., V.18, No.3, pp.1731-1755.

Bellon, A.S.; Mosser, C. and Pardo, E.S. (1994): Geochemical characterization of sedimentary basins by statistical analysis: The Mio-Pliocene sequences of the Vera Basin, SE Spain. Chem. Geol., V.116, pp.229-243.

Benson, H.J. (1994): Microbiological applications, 6P

thP ed. Wm. C. Brown.

Berrow, M.L. and Mitchell, R.L. (1991): Location of trace elements in soil profiles: Total contents of particle size separates. Trans. R. Soc. Edunburgh, V.82, pp.195-209.

Berrow, M.L. and Reaves, G.A. (1984): Background levels of trace elements in soils. Inter. Conf., London, July, 1984.

Berrow, M.L. and Reaves, G.A. (1986): Geoderma, V.37, pp.15-27. Blumenthal, U.J.; Cifuentes, E.; Bennet, S.; Quigley, M. and Ruiz-Palacios, G.

(2001): The risk of enteric infections associated with wastewater reuse: The effect of season and degree of storage of wastewater. Transactions of the Royal Society of Tropical Medicine and Hygiene., V.96, pp.131-137.

Bowen, H.J.M. (1979): Environmental chemistry of the elements. Academic Press Inc. (London) Ltd.

Bowen, H.J.M. (1985): In: Hutzinger, D. (Ed.). The handbook of environmental chemistry., V.1, Part D: The natural environmental and the biogeochemical cycles. Springr-Verlag, New York, pp.1-26.

Boeiw, S.H.U. and Thornton, I. (1985): Environmental geochemistry and health. D. Reidel Publishing Company, Lancaster.

Butzer, K.W. and Hense, C.L. (1968): Desert and river in Nubia, geomorphology and prehistoric environments at the Aswan reservoir. Univ. Wisconsin, press, Madison.

Cary, E.E. (1982): Chromium in air, soil and natural waters. Tower Road, Ithaca, New York, N. Y. 14853, U.S.A.

Cavallaro, N. and McBride, M.B. (1978): Soil Sci. Soc. Am. J., V.42, pp.550. Chapman, H.D. (1965): Diagnostic criteria for plant and soils. Univ. Calif. Diviosion

Agric. Sci. Chen, J. and Barber, S.A. (1990): Soil pH and phosphorous and potassium uptake by

maiz evaluated with an uptake model. Soil Sci. Soc. Am. J., V.54, pp.1032-1036. Christensen, T.H. (1989): environmental aspects of sanitary landfilling. In: Christensen,

T.h.; Cossu, R. and Stegmann, R. (Eds.). Sanitary landfilling: process, technology and environmental impact. Academic Press Ltd, London, p.19-25.

Chumakov, I.S. (1967): Pliocene and Pleistocene deposits of the Nile Valley in Nubia and Upper Egypt. (In Russian). Trans. Geol. Inst. Acad. USSR, V.170, pp.1-110.

Danielsson, A.; Cato, I.; Carman, R. and Rahm, L. (1999): Spatial clustering of metals in the sediments of the Skagerrak/Kattegat. Appl. Geochem., V.14, pp.689-706.

David, M.C. and Robert, E.V. (1973): Device for field determination of selected heavy metals in neutral waters. Environ. Sci. Technol., V.6, No.5 pp.455.

Davies, B.E. (1980): Trace element pollution. In: Davies B.E. (Ed.). Applied soil trace elements. Wiley and Sons, New York, pp.287-351.

Davis, J.C. (1973): Statistical and data analysis in geology. 1P

stP ed., New York, Wiley and

Sons, 550 pp.

REFERENCES

208

Davis, J.C. (1986): Statistical and data analysis in geology. 2P

ndP ed., New York, Wiley

and Sons, 646 pp. Deb, B.C. (1963): FAO report, High dam soil survey project, Aswan. Decau, J.; Fioramanti, S. and Malterre, H. (1963): The organic matter content of soils

of the Haute Garonne. Soils and Fert., V.26, pp.52. De Visser, J.P. (1991): Clay mineral stratigraphy of Miocene to Recent marine

sediments in the central Mediterranean. Geologica Ultraiectina, No.75, 243pp. DEWAS (1980): Deutsche Einheitsverfahren zur wasser abwasser und

schlammuntersuchnung. Weinheim, Germany: Verlag Chemie. Dewis, J. and Freitas, F. (1970): In: Physical and chemical methods of soil and water

analysis. Soil Bulletin, No.10. Food and Agriculture Organization of the United Nations, Rome.

Dzombak, D.A. and Morel F.M.M. (1987): Adsorption of inorganic pollutants in aquatic systems. J. Hydraulic Eng., V.113, pp.430-475.

Eisler, R. (1993): Zinc hazards to fish, wildlife and invertebrates: a synoptic review. U.S. Fish and Wildlife Service Biological Report, V.26, No.10, 106p.

El-Damaty, A.H.; Hamdi, H. and Orabi, A.A. (1971): Factors affecting the manganese status in the soils of U.A.R. U.A.R. J. Soil Sci., V.11, pp.39-46.

El-Desoky, M.A. and Ghallab, A. (1997): Changes in soil properties of a certain parts of wadi El-Assiuti induced by the 1994 Torrent. Proceeding of the First Scientific Conf. Of Agric. Sci., Fac. Agric., Assiut Univ., Assiut, December, V.1, pp. 431-448.

El-Desoky, M.A.; Khalifa, E.M. and Abd El-Aziz, S.H. (2000): Clay mineralogy of some soils of wadi El-Assiuti, Assiut, Egypt. Assiut J. Agric. Sci., V.29, No.4, pp.111-130.

El-Gala, A.M. and Hendawy, S. (1972): Studies on iron availability and behavior in some soils of Egypt. Egypt. J. Soil Sci., V.12, No.1, pp.21-30.

El-Gendi, S.A.; Badawy, S.H. and Helal, M.I.D. (1997): Mobility of some heavy metals nutrients in sandy soils irrigated with sewage sludge effluent. J. Agric. Sci. Mansoura Univ., V.22, pp.3535-3553.

El-Gibaly, M.H.; El-Reweiny, F.M. and Ahmed, M.A. (1970): Micronutrient status of Assiut soils. III- Copper. Assiut J. Agric. Sci., V.1, pp.163-170.

El-Gibaly, M. H.; Khalifa, E. M. and Kishk, M. A. (1972): Carbonate content and its distribution in the soils of Upper Egypt. Assiut J. Agric. Sci., V.3, No.1, pp.437-450.

El-Haddad, A. and El-Shater, A. (1988): Sediments characteristics as a controlling factor of pollution of the groundwater from disposed of wastes, Sohag, Egypt. Sohag Pure & Appl. Sci. Bull. Fac. Sci., V.4, pp.145-162

El-Halawany, K.S.A. (1978): Studies on certain micronutrients in some Egyptian soils under reclamation. M.Sc. Thesis, Fac. Agric., Ain Shams Univ., Egypt.

El-Hussieny, O.H.M. (1995): Pedochemical studies on some soils of Egypt with special reference to some heavy metals. Ph.D. Thesis, Fac. Agric., Moshtohor, Zagazig Univ. Benha Branch, Egypt.

Ellawy, M.; Hart, B.T. and Beckell, R. (1982): Trace metals in sediments from the Yarra River. Aust. J. Mar. Freshw. Res., V.33, pp.761-778.

El-Mowilhi, N.M. and El-Abaseri, M.A. (1979): Micronutrient status in some soils of Kafr El-Sheikh Governorate. Agric. Res. Rev., V.57, pp.149-166.

REFERENCES

209

El-Naggar, Z.R. (1970): On a proposed lithostratigraphic subdivision for the Late Cretaceous-Early Paleocene succession in the Nile Valley, Egypt, U.A.R. 7P

thP

Arab Petroleum Congress. Paper 64 (B-3), Kuwait. El-Nashar, M.B. (1985): Effect of sewage water on soil properties of the Egyptian soil.

Ph.D. Thesis, Fac. of Agric., Monofiya Univ., Egypt. El-Nennah, M.; El-Kobbia, T.; Shehata, A. and El-Gamal, I. (1982): Effect of

irrigation loamy soil by sewage effluent on its content of some nutrients and heavy metals. Plant and Soil, V.65, pp.289-292.

El-Saady, S.A.A. (1991): Study on pollution in Egyptian soils: Effects of some heavy metals on plants and soil. M.Sc. Thesis, Fac. Agric., Tanta Univ., Egypt.

El-Sayed, A.A. (1971): Status of copper and zinc in some soils and plants of the U.A.R. M.Sc. Thesis, Fac. Agric., Ain Shams Univ., Egypt.

El-Sayed, E.A. (1993): Studies on some micronutrients in some soils of El-Fayoum Governorate. M.Sc. Thesis, Fac. of Agric., Cairo Univ., Egypt.

El-Sebaay, M.M.M. (1995): Studies on chemical pollution of different waters with some heavy metals in Fayoum Governorate. M.Sc. Thesis, Fac. Agric. Moshtohor, Zagazig Univ. Benha Branch, Egypt.

El-Shabassy, A.I.; Mitkees; Zikrie, Bis.; Abd El-Malik, S.H.; Hassan, H.M.; Nayroos, F. I. And Abd El-Naim, E. M. (1971): effects of sewage water on the properties of sandy soils. Agric. Res. Rev. Cairo, March, V.49, pp.97-116.

El-Shafei, F.S. and El-Koumy, B.Y. (1994): Influence of use of sewage effluent in irrigation on soil and plants. Menofiya J. Agric. Res., V.19, No.5, pp.2521-2534.

El-Sherif, S.; El-Laboudi, A.; Metwally, S. and Ismail, A. (1970a): Status of manganese as affected by physical and chemical features of some alluvial and marine alluvial soils in the U.A.R. J. Soil Sci. U.A.R., V.10, pp.129-141.

El-Sherif, S.; El-Laboudi, A.; Hamdi, H. and Ismail, A. (1970b): Status of manganese in some calcareous soils in the U.A.R. J. Soil Sci. U.A.R. V.10, pp.235-248.

El-Sokkary, I.H. (1979): The chemical fractionation of soil zinc and its specific and total adsorption by Egyptian alluvial soils. Plant and Soil, V.53, pp.117-129.

El-Sokkary, I.M. and Lag, J. (1979): Status of some trace elements in Egyptian soils and in wheat grains. Beitrage Trop. Landwirtsch, Veterinarmed, V.18, pp.35-47.

El-Toukhy, M.M. (1987): Studies on the status of some nutrient elements in the soils adjacent to Idko Lake, Beheira Governorate. M.Sc. Thesis, Fac. Agric. Cairo Univ.

El-Toukhy, M.M.A. (1995): Studies on land evaluation and land use of some soils in North Delta. Ph.D. Thesis, Fac. Agric., Zagazig Univ., Benha Branch.

El-Wakeel, A.F. and Abd El-Naim, E.M. (1986): The characteristics of Abu Rawash sewage effluents and their effects on some chemical and physical properties of sandy soil and minerals contents of citrus varieties. Minufiya J. Agric. Res., V.11, pp.1131-1151.

European Commission Joint Research Center (2000): Workshop on problems around sludge. 18-19 November 1999 – Stresa, Proceedings.

Facchinelli, A.; Sacchi, E. and Mallen, L. (2001): Multivariate statistical and GIS-based approach to identify heavy metal sources in soils. Environ. Pollut., V.114, pp.313–324.

REFERENCES

210

Faiyad, M.N.; Omran, M.S. and El-Shikha, S.H. (1997): Effects of pollution on soil and plant. 3-Effect of industrial activities on plant growth, yield and their macronutrients content. The 7P

thP International Conference Proceedings

“Environmental protection is must”. Alexandria, Egypt, pp.209-225. Faragallah, M.E.A. (1995): Relative distribution of certain nutrients in soils of the Nile

Valley-Desert interference zone, east of Assiut City. M.Sc. Thesis, Fac. Agric., Assiut Univ., Egypt.

Faragallah, M.E.A. (2001): Some studies on the soils of wadi El-Nuqra, Kom Ombo, Aswan, Egypt. Ph.D. Thesis, Fac. Agric., Assiut Univ., Egypt.

Fathi, A. (1946): The distribution of organic nitrogen and its relations with some physical and chemical properties in the soil profile in a farm at Giza, Egypt. M.Sc. Thesis, Fac. Agric., Cairo Univ., Egypt.

Feenstra, S.; Hussain, R. and Van Der, H.W. (2000): Health risks of irrigation with untreated urban wastewater in the southern Punjab, Pakistan. IWMI Pakistan program, International Water Management Institute, Lahore.

Fergusson, G.E. (1990): The heavy elements: chemistry, environmental impact and health effects. Pergamon Press, New York, 412pp.

Flemming, C.A. and Trevors, J.T. (1989): Copper toxicity and chemistry in the environment: A review. Water, Air and Soil Poll., V.44, pp.143-168.

Folk, R.; Andrew, p. and Lewiss, D. (1970): Detrital sedimentary classification and nomenclature for use in New Zealand. J. Geol. Geophysics, V.13, pp.937-968.

Forstner, U. and Salomons, W. (1980): Trace metal analysis on polluted sediments. I. Assessment of sources and intensities. Environ. Technol. Lett., V.1, pp.494-505.

Forstner, U. and Wittman, G.T.W. (1981): Metal pollution in the aquatic environment. Springer-Verlag, Berlin.

Galloway, J.N. and Likens, G.E. (1979): Limnol. Oceanogr., V.24, pp.427. Gaynor, J.D. and Halstead, R.L. (1976): Chemical and plant extractability of metals

and plant growth on soils amended with sludge. Can. J. Soil Sci., V.56, pp.1-8. Gedroiz, K.K., (1924): Soil unsaturated with bases. Method of determining in soils the

hydrogen present in an absorbed condition. Soil requirement of lime as a neutralizing agent. Russien Jour. Expt. Argon. (Translation), V.22, pp.3-27.

Geladi, P. and Kowalski, B.R. (1986): Partial least-square regression: a tutorial. Anal. Chem. Acta, V.185, pp.1-17.

Ghanem, I.; Hassan, M.N.; Khader, M. and Tadros, V. (1971): Studies on Mn in soils. II-Effect of adding organic materials on the transformation of native Mn. U.A.R. J. Soil Sci., V.11, No.1, pp.125-134.

Ghoneim, M.F.; Hassanein, H.G. and El-Gharably, G.S. (1979): Diagnosis of the nutrient status of citrus orchards in Assiut, Egypt. 2P

ndP Workshop on

Micronutrients and Plant Nutrition in Mediterranean Region, Mariut, Egypt. Ghoneim, M.F.; Abd El-Razek, M.; El-Gharably, G.S. and Abd Ellah, K. (1984a):

Micronutrient status in soil of Upper Egypt. 1. Zinc. Assiut J. Agric. Sci., V.15, pp.15-26. Ghoneim, M.F.; Abd El-Razek, M.; El-Gharably, G.S. and Abd Ellah, K. (1984b):

Micronutrient status in soil of Upper Egypt. 2. Copper. Assiut J. Agric. Sci., V.15, pp.27-38.

Gilkes, R.J. and McKenzie, R.M. (1988): Manganese. In: Graham, R.D.; Hannam, R.J. and Uren, N.C. (Eds). Soils and Plants. Kluwer, Dordrecht, chapter 2.

REFERENCES

211

Goldschmidt, V.M. (1954): Geochemistry. Clarendon Press, Oxford, England. Gomah, H.H. (2001): Assessment and evaluation of certain heavy metals in soils and

plants in Assiut Governorate. Ph.D. Thesis, Fac. Agric., Assiut Univ. Egypt. Goodchild, M.F.; Parks, B.O. and Steyaret, L.T. (1993): Environmental modeling

with GIS. Oxford University Press, New York, USA. Graham, E.R. (1953): Soil mineralogy as an index to trace-element status of some

Australian soils. Soil Sci., V.75, pp.333-343. Hafez, A.A. (1962): Seasonal variations in both irrigation and drainage water in Giza

Governorate, Egypt. M.Sc. Thesis, Fac. Agric., Cairo Univ. Egypt. Hakanson, L. (1977): Sediments as indicators of contamination-investigations in the

four largest Swedish Lakes. Staten Naturverdswerk, rapport No. 92, pp.159. Hamdi, H. (1958): The alluvial soils of Egypt. Fac. of Agric., Univ. of Cairo, Bull. No.193b. Harris, R.F.; Karlen, D.L. and Mulla, D.J. (1996): A conceptional framework for

assessment and management of soil quality and health. In: Doran, J.W. and Jones, A.J. (Eds.). Methods for assessing soil quality

Hawkes, H.E. (1952): Geochemical prospecting in the Blackbird cobalt district, Idaho. Bull. Geol. Soc. Amer., V.63, pp.1-260.

Hegazy, I.M.A. (1993): Studies on soil pollution. M.Sc. Thesis, Fac. Agric., Moshtohor, Zagazig Univ. (Benha), Egypt.

Heinrichs, H.; Schultz-Dobrich, B. and Wedepohl, K.J. (1980): Geochim. Cosmochim. Acta., V.44, pp.1519-1532.

Hesse, P.R. (1998): A textbook of soil chemical analysis. CBS Publ., India. Hinsely, T.D.; Ziegler, E.L. and Barrett, G.L. (1979): Residual effects of irrigation

corn with digested sewage sludge. J. Environ. Qual., V.8, pp.35-38. Holah, Sh.Sh. (1977): Studies on the status of some micronutrients (iron) in Egyptian

soils. Ph.D. Thesis, Fac. Agric., Cairo Univ. Egypt. Holmgren, C.G.S.; Meyer, M.W.; Daniels, R.B.; Kubota, J. and Chaney, R.l. (1986):

J. Environ. Qual., V.16. Holmgren, G.G.S.; Meyer, M.W.; Chaney, R.L. and Daniels, R.B. (1993):

J. Environ. Qual., V.22, pp.335-348. Ibrahim, M. and Omer, A. (2004): Heavy metals contamination in soils of the major

roadway sides and its environmental impact, Sohag, Egypt. The Sec. Int. Conf. For Develop. and the Env. In the Arab World, p.101-120.

Ibrahim, M.S.; Abd Al-galil A. and Kotb M.M. (2001): Total and available Fe, Mn, Zn and Cu in some soils of Sohag Governorate and their association with some soil properties. Assiut J. Agric. Sci., V.32, No.5, pp.71-86.

Iskandar, I.K. (1967): The inter-relationship between groundwater and soil salinity. M.Sc. Thesis, Fac. of Agric., Ain Shams Univ. Egypt.

Ismaeil, S.A.A. (1993): Impact of some soil components on the status of iron, manganese and copper in some calcareous soils in Egypt. Menofiya J. Agric. Res., V.18, No.3, pp.1911-1927.

Issawi, B and McCauley, J.F. (1992): The Cenozoic rivers of Egypt: the Nile problem. In: Freidman, R. and Adams, B. (Eds)., The Followers of Hours: Studies asoc. Public., No.2, Oxbow Mong. 20, Park End Place, Oxford, p.121-138.

Issawi, B.; Hassan, M.W. and Osman, R. (1978): Geological studies in the area of Kom Ombo, Eastern Desert, Egypt. Ann. Geol. Survey, Egypt, V.VIII, pp.187-235.

REFERENCES

212

Jackson, M.L. (1973): Soil chemical analysis. Prentice-Hall, Inc., Englewood Cliffs, N. J. Jarvis, I. and Higgs, N. (1987): Trace-element mobility during early diagenesis in distal

turbidites. Late Quaternary of the Madeira Abyssal Plain, N. Atlantic. In: Weaver, P.P.E. and Thomson J. (Eds.), Geology and Geochemistry of Abyssal Plains. Geol. Soc. London, Spec. Pupl., V.31, pp.179-213.

Jones, B. and Turki, A. (1997): Distribution and speciation of heavy metals in surficial sediments from the Tees Estuary, North-east England. Marine Pollution Bulletin, V.34, No.10, pp.768-779.

Joreskog, K.G.; Kloven, J.E. and Reyment, R.A. (1976): Geological factor analysis. Amesterdam, Elsevier, 177p.

Kabata-Pendias, A. (1993): Behavioral properties of trace metals in soils. Appl. Geochem. Suppl., V.2, pp.3-9.

Kabata-Pendias, A. (1995): Agricultural problems related to excessive trace metal contents of soil. In: Heavy Metals (Problems and Solution), Salomons, W., Förstner, U. and Mader, P., (Eds). Springer Verlag, Berlin, Heidelberg, New York, London, Tokyo., pp.3-18.

Kabata-Pendias, A. and Pendias, H. (1984): Trace elements in soils and plants. 2P

ndP Ed. CRC Press, Inc., London, pp.113-153.

Kabata-Pendias, A. and Pendias, H. (1992): Trace elements in soils and plants. CRC Press, Inc. Boca Roton, Florida., 365p.

Karim, A. and Hussain, M.S. (1970): Profile distribution of different forms in some East Pakistan. J. Sci. Ind. Res., V.12, pp.365-369.

Kelley, W.P. (1964): Review of investigations on cation exchange and semiarid soils. Soil Sci., V.97, pp.80-88.

Kemp, A.L.W.; Williams, J.D.H.; Thomas, R. L. and Gregory, M. L. (1978): Water, Air and Soil Pollut., V.10, pp.381.

Khalid, R.A. (1980): Chemical mobility of cadmium in sediment water systems. In: Nriagu, J.O. (Ed.). Cadmium in the environment: Part 1. John Wiley & Sons, New York, pp.258-304.

Kishk, F.M.; Hassan, M.N.; Ghanem, I. and El-Sissy, L. (1973): Status of copper in some calcareous and non-calcareous soils of Egypt. Plant and Soil, V.39, pp.487-496.

Kishk, M.A.; Abd El-Razek, M. and El-Gharably, G. S. (1980): Status of certain micronutrients in some selected soils from Middle and Upper Egypt. Assiut J. Agric. Sci., V.11, pp.197-206.

Knight, R.D. and Klassen R.A. (2001): Environmental geochemistry and geochemical hazards. In: Brooks, G.R. (Ed.). A synthesis of geological hazards in Canada. Geological Survey of Canada Bulletin, pp. 227-230.

Kumar, P.J. and Clark, M.L. (1991): Clinical medicine. 2P

ndP Ed., pp.163-752. ELBS

Bailliere Tindall Great Britain. Kuo, S. and Baker, A.S. (1980): Soil Sci. Soc. Am. J., V.44, pp.969. Labib, M.T.; El-Hassanin, A.S. and Dobal, A.T. (1992): Changes in some soil

characteristics due to recent and long-term sewage water irrigation. Water Sci. 11P

thP Issue. April. 1992.

Lag, J. (1989): Excess and deficiency of trace elements in relation to human and animal health in arctic and subarctic regions. University of Florida.

REFERENCES

213

Lake, D.L.; Kirk, P.W.W. and Lester, J.N. (1984): Fractionation, characterization and speciation of heavy metals in sewage sludge-amended soils: a review. J. Environ. Qual., V.13, p.175-183.

Langer, M. (1995): Engineering geology and waste disposal - scientific report and recommendations of the IAEG Commission No.14, Bull Assoc. Eng. Geol., V.51, pp.429-435.

Le Maitre, R.W. (1982): Numerical petrology. Statistical interpretation of geochemical data. Chapter 9: Multiple discriminant analysis, in developments in petrology 8. New York, Elsevier, pp.141-162.

Lemoni-Relis, B. and Eren, J. (1994): Chemical and microbial indicators of contamination in groundwater. In: Zoller, U. (Ed.), Groundwater contamination and controls. Marcel Dekker, Inc. New York, Basel, Hong Kong, pp.391-398.

Li, X.D. and Thornton, I. (2001): Chemical partitioning of trace and major elements in soils contaminated by mining and smelting activities. App. Geoch., V.16, pp.1693-1706.

Li, X.D.; Shen, Z.; Wai, O.W.H. and Li, Y.S. (2000): Chemical partitioning of heavy metal contaminants in sediments of the Pearl River Estuary.

Lindsay, W. L. (1972): Inorganic phase equilibrium of micronutrients in the soil. Chapter 3 in Micronutrients in Agriculture, pp.41-58.

Lindsay, W.L. and Norwell, W.A. 1978: Development of a DTPA soil test for zinc, iron, manganese and copper. Soil Sci. Soc. Am. J., V.42, pp.421-428.

Linz, D.G., and Nakles, D.V., (1997): Environmentally acceptable endpoints in soil. Annapolis, MD: American Academy of Environmental Engineers.

Malewar, G.V.; Varade, S. B. and Jaohav, N.S. (1978): Distribution of Mn and Cu in some soils of the citrus growing tract of Marath Wada. Indian J. Agric. Res., V.12, pp.227-230.

Mansour, A.M. (2003): Suitability of Quaternary sediments to waste landfills in Qena, Egypt. Sedimentology of Egypt, V.11, pp.169-183.

Mason, B. and Moore, C.B. (1982): Principles of geochemistry. 4P

thP ed., Wiley, New York.

Massart, D.L. and Kaufman, L. (1983): The interpretation of analytical chemical data by the use of cluster analysis. John Wiley & Sons, Inc., 237p.

Mattigod, S.V. and Page, A.L., (1983): Assessment of metal pollution in soils. In: Thornton, I. (Ed.), Applied environmental geochemistry, Academic Press INC., London, pp.355-394.

McGrath, S.P. (1995): Chromium and Nickel. In “Heavy metals in soils” 2P

ndP ed. by

Alloway, B. J. Blackie Academic and Professional, pp.152-177. McGrath, S.P. and Loveland, P.J. (1992): The soil geochemical atlas of England and

Wales. Blackie Academic and Professional. Meiggs, T.O. (1980): The use of sediment analysis in forensic investigations and

procedual requirements for such studies. In: Baker RA (Ed.) contaminants and sediments, Ann. Arbor Sci. Publ., Ann. Arbor, Mich., V.1, pp.297-308.

Mertz, W. (1986): Trace elements in human and animal nutrition. Academic Press, London. Metwally, A.I. and Abdellah, A. (1978): Iron status and availability in calcareous and non-

calcareous soils in Egypt. Beitrag Trop. Landwirtsch Veterinarme, V.16, pp.163-168.

REFERENCES

214

Metwally, A.I.; El-Kobia, T. and Omar, M.A. (1971): Evaluation of easily reducible manganese as a measure of the plant available manganese in some soils of U.A.R. J. Soil Sci. U.A.R., V.11, pp.1-6.

Mezzadri, G. and Saccani, E. (1989): Heavy mineral distribution in the late Quaternary sediments of the Southern Aegean Sea: Implication for provenance and sediment dispersed in sedimentary basins at active margins. J. Sed. Petrol., V.59, pp.412-422.

Millward, G.E.; Rowley, C.; Sands, T.K.; Howland, R.J.M.and Pantiulin, A. (1999): Metals in the sediments and mussels of the Chupa estuary (White Sea) Russia. Estuary. Coast. Shelf Sci., V.48, pp.13-25.

Mingel, K. and Kirkby, E.A. (1978): Principles of plant nutrition. International Patash. Institute, Worblaufen-Bern S93.

Mitchell, R.L. (1954): Trace elements in some constituent species of moorland grazing. J. Br. Grass. Soc., V.9, pp.301.

Mitchell, R. L. (1964): In: Bear, F.E. (Ed.). Chemistry of the soil. Van Nostrand Reinhold, New York, Chapter 8.

Mitwally, S.D.Y. (1963): Study on single values of the Nile alluvial soils. Ph.D. Thesis, Fac. Agric., Ain Shams, Egypt.

Molinaroli, E.; Blom, M. and Basu, A. (1991): Methods of provenance determination tested with discriminant function analysis. J. Sed. Petrol., V.61, pp.900-908.

Montgomery, C.W. (1986): Environmental geology. Wm. C. Brown Publishers. Mostafa, H.A. (1979): Geology of the area northeast of Sohag. M.Sc. Thesis, Fac. Sci.,

Assiut Univ., Branch of Sohag. Nair, K.P.P. and Cottenie, A. (1971): A statistical evaluation of the interrelationship

between particle size fractions, free iron oxides and trace elements. J. Soil Sci., V.22, pp.203-209.

National Environmental Policy Institute (NEPI) (2000): Assessing the bioavailability of metals in soil for use in human health risk assessment. Washington, D.C.

National Research Council (NRC) (2003): Bioavailability of contaminants in soils and sediments: processes, tools and applications. The National Academy of Sciences, 416 p.

Neelakantan, V. and Mehta, B.V. (1961): Copper status of soils of Western India. Soil Sci., V.91, pp.251-256.

Negim, O.E.A. (2003): Some studies on soils of the college of Agriculture Farm, South Valley University. M.Sc. Thesis, Fac. Agric., Assiut Univ., Egypt.

Norrish, K. (1975): The geochemistry and mineralogy of trace elements. In: Nicholas, D.J.D. and Egan, A.R. (Eds.). Trace element in soil-plant-animal systems. Academic press, New York.

Nriagu, J.O. (1978): The biogeochemistry of lead in the environment. Nriagu, J.O. (Ed.) Elsevier-North Holland, Amsterdam.

Nriagu, J.O. (1980): The biochemistry of nickel in the environment. John Wiley, New York.

Nriagu, J.O. (1981): Cadmium in the environment. Part II: Health effects. John Wiley, New York.

REFERENCES

215

Omara, S., El-Tahlawi, M.R. and Abd El-Kireem, H. (1973): Detailed geological mapping of the area between the Nile Valley. Bull. Fac. Eng., Assiut, Univ., V.1, pp.141-166.

Omer, A.A.M. (1996): Geological, mineralogical and geochemical studies on the Neogene and Quaternary Nile basin deposits, Qena-Assiut stretch, Egypt. Ph.D. Thesis, Geology Dept., Fac. Sci. Sohag, South Valley University. 320 p.

Omer, A.A.M. (2003a): Variability and speciation of heavy metals in surficial sediments from the River Nile, Egypt: assessment of the anthropogenic impact. The 3P

rdP

International Conference on the Geology of Africa, Assiut-Egypt, V.1, pp.1-19. Omer, A.A.M. (2003b): Impact of the Pleistocene Nile basin sediments on the

distribution of iron and manganese in the groundwater, Tema-Nag Hammadi area, Nile Valley, Egypt. The 3P

rdP International Conference on the Geology of

Africa, Assiut-Egypt., V.1, pp.21-37. Omer, A.A.M., and Issawi, B. (1998): Lithostratigraphical, mineralogical and

geochemical studies on the Neogene and Quaternary Nile basin deposits, Qena-Assiut stretch, Egypt. The 4P

thP International Conference on Geology of the Arab

World, Cairo. (Abstract). Omer, A.A.M. and Abdel Moneim A.A. (2001): Geochemical characteristics of the

Pliocene and Pleistocene Nile basin deposits and their influence on the groundwater chemistry in Sohag area. Annals Geol. Surv. Egypt. V.XXIV, pp.567-584.

Omer, A.A.M. and Hassan, A.M. (2004): Geochemistry and mineral composition of the Upper Cretaceous silisiclastics (Nubia Group), northeast of Aswan: implication for provenance and weathering. Ann. Geol. Surv. Egypt. V.XXVI, pp.273-294.

Omran, M.S.; Shalaby, M.H. and Raslan, M.I. (1996): Effect of soil pollution on growth and active ingredient of some medicinal plants. Egypt. J. Soil Soc., V.36, pp.59-67.

Orabi, A.A. (1968): Factors affecting manganese availability. M. Sc. Thesis, Fac. Agric., Ain Shams Univ., Egypt.

Pathak, A.N.; Tiwari, K.N. and Prasad, D.D. (1979): An appraisal of available and potentially available iron status of alluvial soils of Uttar Pradesh. J. Indian Soc. Soil Sci., V.27, No.2, pp.191-193.

Paulissen, M. and Vermeersch, P.M. (1987): Earth, man and climate in the Egyptian Nile Valley during the Pleistocene. In: Close, A. (Ed.), Prehistory of North Africa. Southern Methodist University Press, Dallas, p.29-67.

Pierce, F.J.; Dowdy, R. H. and Grigal, I.F. (1982): Concentration of six trace metals in some major Minnesota soil series. J. Environ. Qual., V.11, pp.416-422.

Queralt, I. and Plana, F. (1992): Partitioning of heavy metals in particle size fractions: A tool to predict metal mobility and distribution in the environment. In: Eijsackers, H. J. P. and Hamers, T. (Ed.). First European Conf. on Integrated Research for Soil and Sediment Protection and Remediation. Kluwer Academic Publ., Dordrecht, the Netherlands, pp.276-278.

Rabie, F.; Rashad, I.F.; Khader, M. and Hussein, W. (1996): Contents of biogenic and non-biogenic heavy metals in El-Saff soils as related to different pollution sources. Egypt. J. Soil Sci., V.63, No.1-4, pp.165-177.

Ramadan, M.A. (1995): Studies on the pollution of the agriculture environment in Egypt. Ph.D. Thesis, Fac. Agric., Cairo Univ., Egypt.

REFERENCES

216

Rankama, K. and Sahama, Th.G. (1968): Geochemistry. Univ. of Chicago Press, Chicago, Illinols. 912 pp.

Rashad, I.F. (1986): Accumulation and distribution of trace elements in soil profiles of El-Gabal El-Asfar through long term irrigation with wastewater. Ph.D. Thesis, Fac. Agric., Mansoura Univ., Egypt.

Rashad, I.F.; Abdel Nabi, A.O.; Hensely M.E. and Khalaf, M.A. (1995): Background levels of heavy metals in the Nile Delta soils, Egypt. J. Soil Sci., V.35, pp.239-252.

Ravikovitch, S.; Margolin, M. and Navort, J. (1968): Zinc availability in calcareous soils: I. Comparison of chemical extraction methods for estimation of plant available zinc. Soil Sci., V.105, pp.57-60.

Reitner, J.; Kralik, M. (1997): Aktugeologie eines naturnahen Gerinnes: Sedimentgeologie und umweltgeologie am beispiel des marchfeldkanals. Mitt. Sterr. Geol. Ges., V.88, pp.79-96, Wien.

Reuther, W. (1957): Copper and soil fertility. U.S.A. Exp. Agr. Year book, pp.122-134. Roser, B.P. and Korsch, R.J. (1988): Provenance signature of sandstone-mudstone

suites determined using discriminant function analysis of major-element data. Chemical Geology, V.67, pp.119-139.

Ruby, M.V.; Davis, A. and Nicholson, A. (1994): In situ formation of lead phosphates in soils as a method to immobilize lead. Environ. Sci. Technol., V.28, pp.646-654.

Said, R. (1960): Planktonic foraminifera from the Thebes Formation, Luxor, Egypt. Micropaleontology, V.16, pp. 227-286.

Said, R. (1971): Explanatory notes to accompany the geological map of Egypt 1:2,000,000.Geol. Surv. Egypt. Paper 56,123pp.

Said, R. (1975): The geological evolution of the river Nile. In: Problems in Prehistory of Northern Africa and the Levant. Wendorf, F. and Marks, A. F. (Eds.). Southern Methodist University Press. Dallas, Texas, pp.1-44.

Said, R. (1981): The geological evolution of the River Nile. Springer-Verlag, New York. 151p.

Said, R. (1983): Proposed classification of the Quaternary of Egypt. J. African Earth Sciences., V.1, p.41-45.

Said, R. (1990): The geology of Egypt. Egyptian General Corporation, Conoco Hurghada Inc. and Repsol Exploration, S. A., Balkema, Rotterdam, Brookfield, 731p.

Said, R. (1993): The River Nile: geology, hydrology and utilization. Pergamon Press, Oxford, New York, 320p.

Salomonos, W. and Forstner, U. (1984): Metals in the hydrocycle. Springer-Verlag, Berlin Heidelberg, New York, Tokyo.

Schirado, T.; Vergara, I.; Schalscha, E.B. and Pratt, P.F. (1986): Evidence for movement of heavy metals in a soil irrigated with untreated wastewater. J. Environ. Qual., V.15, No.1, pp.9-12.

Sedberry, J.E.; Harim, Jr. H. and Miller, B. J. (1978): The profile distribution of total and DTPA-extractable manganese in selected soils from the major mineral soils areas in Louisiana. Communication in Soil Science and Plant Analysis, V.9, No.5, pp.389-401.

REFERENCES

217

Shende, G.B.; Chakrabarti, C.; Rai, R.P.; Nashikkar, V.J.; Kshirsagar, D.G.; De Shbhratar, P.B. and Juwarkar, A.S. (1985): In “Treatment and use of sewage effluent for irrigation”. (Pescod, M. B. and Arar, A. Eds., pp.185-209. Butterworths, London).

Shuman, L.M. (1978): Zinc, manganese and copper in soil fractions. Soil Sci., V.127, pp.10-15.

Shuval, H.I.; Wax, Y.; Yekutiel, P. and Fattal, B. (1989): Transmission of enteric disease associated with wastewater irrigation: A prospective epidemiological study. American Journal of Public Health., V.79, No.7, pp.850-852.

Siegel, F.R.; Slaboda, M.L. and Stanley, D.J. (1994): Metal pollution loading, Manzalah lagoon, Nile Delta, Egypt: Implications for aquaculture. Environmental Geology, V.23, pp.89-98.

Sillanpaa, M. (1972): Trace elements in soils and agriculture. FAO, Rome Soil Bulletin., No.170.

Singh, D.; Dogne, R.S. and Dikshite, R.G. (1969): Copper status of medium black soils, Indore District. Indian J. Agric. Chem., V.2, pp.67-73.

Smith, K.A. (1990): Manganese. In: Alloway, B.J. (Ed.). Heavy metals in soils. John Wiley & Sons Inc., New York.

Smith, S.J. and Cassel, D.K. (1991): Estimating nitrate leaching in soil materials. In: Follett, R.F. (Ed.), Managing N for ground water quality and farm profitability. SSSA, Madison, WI, p.165-188.

Soil Science Society of America (1987): Glossary of soil science terms. Rev. ed. Soil Sci. Soc. of Am., Madison, WI.

Soon, Y.K. (1981): J. Soil Sci., V.32, pp.85. Srivastva, A.R.; Dubey, R.R. and Sinha, H. (1970): Manganese status of Bihar soils.

Indian J. Agric. Chem., V.3, pp.42-48. STATISTICA 5 FOR WINDOWS (1995): Advanced statistical package.

Statsoft, Inc. Tusla, U.S.A. (www.statsoft.com) Stattegger, K. (1987): Heavy minerals and provenance of sands: modeling of

lithological end members from river sands of northern Austria and from sandstones of the Austroalpine Gosau Formation (Late Cretaceous). J. Sed. Petrol., V.57, pp.301-310.

SURFER 8 FOR WINDOWS (2002): Surface mapping system package. Golden Software Inc., U.S.A. (www.goldensoftware.com)

Swaine, D.J. (1995): The trace element content of soils. Commonukath Bur. Soil Sci. Tech. Common., No.48.

Swaine, D.J. and Mitchell, R.L. (1960): J. Soil Sci., V.11, pp.348-368. Taha, S.A. (1980): Studies on manganese in some soils of Egypt.

Ph.D. Thesis, Fac. Agric., Cairo Univ., Egypt. Taher, A.G. and Attia, O.E.A. (1999): Trace metal geochemistry of El-Sheikh Zuweid

modern playa sediments, Egypt. Geological Society of Egypt. Tayel, M.Y; Hamdi, H. and Abdel Ghani, A.M. (1966): Iron status and behavior in the

soils of Egypt. Beiter. Trop. Landw. Vetmed.; V.1, pp.27-38. Taylor, J.K. (1988): Quality assurance of chemical measurements.

Lewis Publ., Inc., Chelsea, MI.

REFERENCES

218

Taylor, S.R. and McLennan, S.M. (1985): The continental crust: its composition and evolution. Blackwells, 312p.

TEP (Texas Environmental Profile) (2002): Point-source discharges. http://www.texasep.org/html/wq1/wq1_2sfc_ps.html

Tessier, A., Campbell, P.G.C. and Bisson, M. (1979): Sequential extraction procedure for the speciation of particulate trace metals. Anal. Chem. V.51, pp.844-851.

Thornton, I. (1986): Proceeding of the first symposium on geochemistry and health. Science Reviews Ltd., Northwood.

Thornton, I. (1988): Proceeding of the second symposium on geochemistry and health. Science Reviews Ltd., Northwood

Thornton, I. (1995): Metals in the global environment: facts and misconceptions. International Council on Metals and the Environment, Ottawa, Canada, 105 p.

Thornton, I. and Webb, J.S. (1980): In: Davies, B.E. (ed.), Applied soil trace elements, Wiley, New York, pp.381-439.

Turekian, K.K. and Wedepohl, K.H. (1961): Distribution of the elements in some major units of the earth’s crust. Geological Society of American Bulletin, V.72, p.175-192.

Ure, A.M. and Berrow, M.L. (1982): The elemental constituents of soils. In: Environmental Chemistry, V.2. Royal Society of Chemistry, London, Chapter 3.

Ure, A.M.; Quevaullier, Ph; Muntau, H. and Griepink, B. (1993): Speciation of heavy metals in soil and sediments. An account of the improvement and harmonization of extraction techniques undertaken under the auspices of the BCR of the CEC. Int. J. Environ. Analyt. Chem., V.51, p.135-151.

USDA, (Soil Survey Division Staff) (1993): Soil survey manual. USDA Handb. No.18, U.S. Gov. Print Office, Washington, DC.

USDA, (Soil Survey Laboratory Methods Manual) (1996): Soil Survey Investigations. Report No.42, V.3, Washington, D. C.

Viets, Jr.F.G. and Lindsay, W.L. (1973): Testing soils for Zn, Cu, Mn and Fe. In: Walsh, L. O. and Beaton, J. D. (Ed.). Soil testing and plant analysis. Soil Sci. Soc. Am. Inc. Madison, Wisconsin, USA, pp.153-172.

Vinogradov, A.P. (1959): The geochemistry of rare and dispersed chemical elements in soils. Consultants Bureau Inc., New York.

Waksman, S.A. and Purvis, E.R. (1932): The influence of moisture upon the rapidity of decomposition of Lowmoor peat. Soil Sci., V.34, pp.323-336.

Weast, C. (1969): Handbook of geochemistry and physics. 50P

thP Ed. Chemical Rubber

Co. Cleveland, Ohio. Wells, N. (1960): Total elements in topsoils from igneous rocks; an extension of

geochemistry. J. Soil Sci., V.11, pp.409-424. Wixon, N.G. and Davis, B.E. (1994): Environ. Sci. Technol., V.28, pp.26A-31A. World Health Organization (WHO) (1971): International standards for drinking water.

3P

rdP ed., Geneva, Switzerland.

World Health Organization (WHO) (1982): Micropollutants in river sediments. Euro Reports and Studies 61, Copenhagen.

World Health Organization (WHO) (1993): Guidelines for drinking-water quality. 2P

ndP ed., V.1, pp.40, Recommendations. Geneva, Switzerland.

REFERENCES

219

World Health Organization (WHO) (1996): Trace elements in human nutrition and health.

Zaki, R.M.; El-Bakry, A.; El-Shemi, A. and Fanous, F.A. (2000): Mineralogy and geochemistry of some Nile alluvial plain sediments, Minia, Egypt. Bull. Fac. Sci., Assiut Univ., V.30 (1-F), pp.53-72.

Zeinel-Abdine, A.; Fathi, A. and El-Arkan, M.Y.S. (1966): Studies on the subdeltaic sandy formations and their effect on the adjacent soils of the Nile Delta, U.A.R. J. Soil Sci., U.A.R., V.6, pp.37-49.

APPENDICES

APPENDICES

220

APPENDICES Appendix (A): Selected physical and chemical properties of the examined

sediments. A-1: Cultivated floodplain (topsoil layer)

CaCOB3 B(%) OM (%) Texture grade SN ID pH <63µm <2mm <63µm <2mm

Sand (%)

Silt(%)

Clay(%) I II

1 1 8.2 10.1 10.3 2.35 1.48 17 58 25 Sandy silt Silt loam 2 2 8.2 4.4 5.2 1.11 1.70 20 68 12 Sandy silt Silt loam 3 3 8.3 7.1 7.2 2.01 2.20 15 63 22 Sandy silt Silt loam 4 7 8.2 4.1 4.0 2.08 2.20 12 67 21 Sandy silt Silt loam 5 19 8.1 2.3 1.9 2.48 1.45 17 66 17 Sandy silt Silt loam 6 22 8.2 4.2 5.0 1.91 2.10 7 75 18 Silt Silt loam 7 31 8.0 8.9 5.4 2.15 1.33 39 43 18 Sandy silt Loam 8 32 7.9 4.7 3.4 1.58 1.66 17 69 14 Sandy silt Silt loam 9 33 8.3 2.4 2.1 1.31 0.82 12 77 11 Sandy silt Silt loam

10 112 7.8 2.4 1.6 2.30 1.09 15 58 27 Sandy silt Silt loam 11 113 7.8 3.5 2.0 2.80 2.50 7 55 38 Mud Silty clay loam 12 114 7.8 3.7 2.0 2.40 2.40 33 49 18 Sandy silt Loam

13 63 8.4 6.5 4.6 2.65 0.93 20 67 13 Sandy silt Silt loam 14 64 8.1 3.8 2.1 2.25 1.77 18 72 10 Sandy silt Silt loam 15 73 8.3 4.9 5.8 2.11 1.45 27 53 20 Sandy silt Silt loam 16 74 8.4 3.8 3.9 1.99 2.20 12 67 21 Sandy silt Silt loam 17 88 8.2 9.9 8.6 2.60 1.20 51 26 23 Muddy sand Sandy clay loam 18 102 7.4 1.9 0.3 2.20 1.48 7 70 23 Silt Silt loam 19 103 7.7 3.7 1.9 1.70 1.36 9 72 19 Silt Silt loam 20 104 7.7 2.7 1.4 2.00 2.30 7 73 20 Silt Silt loam 21 105 7.9 2.6 1.0 1.40 1.11 19 64 17 Sandy silt Silt loam 22 106 7.9 4.1 2.8 1.90 1.80 4 66 30 Silt Silty clay loam 23 107 8.0 4.1 2.8 3.20 2.17 8 59 33 Mud Silty clay loam 24 108 7.9 6.2 6.6 2.50 1.73 14 50 36 Sandy mud Silty clay loam 25 109 8.2 3.9 3.5 1.90 1.51 3 53 44 Mud Silty clay 26 110 8.0 8.0 5.8 1.60 1.16 24 52 24 Sandy silt Silt loam 27 111 7.8 7.1 5.4 2.10 1.37 18 55 27 Sandy silt Silt loam 28 115 7.9 2.5 3.2 1.90 1.90 33 60 7 Sandy silt Silt loam 29 116 7.9 2.8 1.8 1.90 1.59 12 73 15 Sandy silt Silt loam 30 117 7.8 2.5 1.0 2.10 2.20 8 77 15 Silt Silt loam 31 147 8.4 5.6 2.0 2.60 2.10 25 42 33 Sandy mud Clay loam 32 148 8.5 6.5 6.3 1.90 1.65 14 62 24 Sandy silt Silt loam 33 149 9.0 2.0 5.2 2.30 2.00 22 69 9 Sandy silt Silt loam 34 150 8.3 6.5 4.8 2.30 0.90 63 30 7 Silty sand Sandy loam 35 154 8.2 2.7 2.1 1.80 2.10 13 70 17 Sandy silt Silt loam

1-12 east of the Nile; 13-35 west of the Nile; I=Folk et al. (1970); II=USDA (1993)

APPENDICES

221

A-2: Cultivated floodplain (subsoil layer)


Sand(%)

Silt(%)

Clay(%) I II

36 1 8.3 8.9 7.4 1.02 0.82 11 79 10 Sandy silt Silt loam


38 3 8.1 7.3 6.9 1.48 1.11 20 50 30 Sandy mud Clay loam

39 7 8.2 4.2 2.3 0.89 0.47 9 73 18 Silt Silt loam


41 22 8.1 4.6 3.2 1.63 1.01 3 82 15 Silt Silt loam

42 31 8.2 5.2 5.0 1.07 0.57 33 43 24 Sandy mud Loam

43 32 8.1 1.3 2.8 1.01 0.98 7 79 14 Silt Silt loam

44 33 8.1 2.5 2.6 0.65 0.68 6 84 10 Silt Silt

45 112 7.9 2.8 2.0 1.60 0.70 4 45 51 Mud Silty clay

46 113 7.8 3.5 2.2 1.70 1.08 5 55 40 Mud Silty clay loam


48 63 8.5 5.3 4.2 1.21 0.94 11 54 35 Sandy mud Silty clay loam

49 64 8.1 4.7 2.9 1.67 0.94 8 79 13 Silt Silt loam


51 74 8.3 6.0 4.6 1.21 0.78 9 75 16 Silt Silt loam

52 88 8.2 20.8 6.7 1.50 0.58 66 14 20 Muddy sand Sandy loam

53 102 7.6 1.8 1.1 1.20 0.83 8 66 26 Silt Silt loam

54 103 7.7 3.2 1.5 1.40 0.72 6 78 16 Silt Silt loam

55 104 7.8 3.4 2.1 1.60 0.97 5 68 27 Silt Silt loam


57 106 8.0 3.7 2.4 1.20 0.84 4 74 22 Silt Silt loam

58 107 8.1 4.2 2.2 2.00 1.09 5 41 54 Mud Silty clay

59 108 8.0 3.8 5.5 1.20 0.89 10 47 43 Sandy mud Silty clay

60 109 8.2 4.4 3.2 1.31 0.82 4 43 53 Mud Silty clay

61 110 8.2 6.2 4.6 1.00 0.67 13 60 27 Sandy silt Silty clay loam

62 111 8.0 5.3 3.4 1.00 0.78 7 53 40 Mud Silty clay loam




66 147 8.5 3.5 3.4 1.60 1.05 21 35 44 Sandy mud Clay



69 150 8.2 10.1 4.2 1.70 0.76 59 28 13 Silty sand Sandy loam


36-47 east of the Nile; 48-70 west of the Nile

APPENDICES

222

A-3: Reclaimed lands (topsoil layer)

CaCOB3 B(%) OM (%)* Texture grade SN ID pH <63µm <2mm <63µm <2mm

Sand(%)

Silt(%)

Clay(%) I II






76 11 7.9 10.7 3.3 0.74 0.90 12 82 6 Sandy silt Silt


78 20 8.2 15.5 20.4 1.11 0.54 51 40 9 Silty sand Loam


80 23 8.2 3.7 5.5 1.41 0.98 46 44 10 Sandy silt Loam


82 28 8.4 18.3 14.2 2.38 2.10 49 36 15 Sandy silt Loam


84 55 7.9 22.2 17.1 1.48 0.71 46 42 12 Sandy silt Loam


86 57 8.4 8.4 6.4 1.48 1.10 44 37 19 Sandy mud Loam

87 58 8.2 6.4 5.5 2.01 1.23 52 37 11 Silty sand Loam


89 62 8.3 8.4 6.7 2.31 2.19 51 35 14 Silty sand Loam





94 70 8.2 7.0 8.6 2.08 1.20 43 40 17 Sandy silt Loam



97 85 7.5 3.5 6.6 1.90 1.70 43 42 15 Sandy silt Loam

98 87 8.0 5.6 5.0 2.10 1.34 16 49 35 Sandy mud Silty clay Loam

99 101 7.2 35.4 7.7 0.60 0.10 95 4 1 Sand Sand

100 118 8.4 4.2 4.5 1.70 0.82 38 49 13 Sandy silt Loam


102 125 8.0 20.2 7.9 2.80 1.20 83 12 5 Muddy sand Loamy sand



APPENDICES

223

A-4: Reclaimed lands (subsoil layer) CaCOB3 B(%) OM (%)* Texture grade SN ID pH

<63µm <2mm <63µm <2mm

Sand(%)

Silt(%)

Clay(%) I II


105 5 8.3 10.1 24.6 0.80 0.40 35 46 19 Sandy silt Loam

106 6 8.1 42.2 59.8 0.50 0.11 83 15 2 Silty sand Loamy sand







113 23 8.3 31.8 12.0 0.22 0.04 96 2 2 Sand Sand

114 26 8.3 46.1 7.0 0.41 0.03 92 5 3 Sand Sand

115 28 8.3 32.6 24.2 0.49 0.10 93 6 1 Sand Sand


117 55 8.0 5.9 12.7 1.31 0.84 51 36 13 Silty sand Loam


119 57 8.5 28.4 9.7 0.22 0.06 94 3 3 Sand Sand

120 58 9.0 33.4 12.5 0.52 0.07 97 2 1 Sand Sand


122 62 8.8 30.9 18.1 0.29 0.06 95 4 1 Sand Sand

123 65 8.6 32.9 13.7 0.27 0.03 97 1 2 Sand Sand

124 67 8.6 38.5 6.6 0.30 0.06 96 2 2 Sand Sand

125 68 8.5 35.4 15.5 0.34 0.03 97 1 2 Sand Sand

126 69 8.2 60.7 14.6 0.39 0.17 95 4 1 Sand Sand



129 72 8.5 30.6 11.0 0.69 0.11 91 7 2 Sand Sand

130 85 8.3 20.8 9.8 0.40 0.06 96 2 2 Sand Sand


132 118 8.1 22.0 11.5 1.60 0.14 96 1 3 Sand Sand

133 124 7.3 29.2 7.0 8.40 1.24 86 13 1 Silty sand Sand

134 125 8.3 38.8 9.2 0.70 0.03 95 4 1 Sand Sand



APPENDICES

224

A-5: Wadi deposits CaCOB3 B(%) OM (%) Texture grade SN ID pH

<63µm <2mm <63µm <2mmSand (%)

Silt(%)

Clay(%) I II

136 9 8.2 41.0 23.2 0.32 0.50 62 34 4 Silty sand Sandy loam 137 12 7.8 30.6 21.0 1.01 0.80 54 41 5 Silty sand Sandy loam 138 13 8.1 18.3 29.1 1.64 0.57 73 22 5 Silty sand Sandy loam 139 14 8.3 28.7 37.8 0.20 0.07 73 22 5 Silty sand Sandy loam 140 15 8.2 30.1 58.4 0.29 0.12 69 27 4 Silty sand Sandy loam 141 16 7.8 24.7 32.0 0.30 0.07 74 19 7 Silty sand Sandy loam 142 17 8.0 29.2 16.8 0.65 0.24 66 24 10 Silty sand Sandy loam 143 25 8.4 30.4 10.9 0.40 0.03 93 3 4 Sand Sand 144 27 8.3 26.7 32.8 0.59 0.20 94 5 1 Sand Sand 145 29 8.2 21.9 21.2 3.42 1.19 41 53 6 Sandy silt Silt loam 146 30 7.8 18.3 27.6 1.64 2.46 35 55 10 Sandy silt Silt loam 147 59 8.6 56.8 16.6 0.27 0.04 91 6 3 Sand Sand 148 61 8.6 32.0 9.8 0.13 0.14 92 5 3 Sand Sand 149 66 8.2 31.5 6.3 0.35 0.11 92 7 1 Sand Sand 150 86 8.2 34.9 13.3 0.70 0.02 95 3 2 Sand Sand 151 151 8.3 50.0 17.1 0.50 0.04 76 22 2 Silty sand Loamy sand 152 152 8.7 47.2 12.2 0.70 0.04 78 17 5 Silty sand Loamy sand

136-146 east of the Nile; 147-152 west of the Nile A-6: Lands applied for wastewater disposal at El-Kola (ponds and

wetlands). CaCOB3 B(%) OM (%)* Texture grade SN ID pH

<63µm <2mm <63µm <2mmSand(%)

Silt(%)

Clay(%) I II

153 34 8.4 31.8 8.9 0.30 0.01 87 9 4 Muddy sand Loamy sand 154 35 8.3 60.0 59.5 0.35 0.10 71 21 8 Silty sand Sandy loam 155 36 8.0 55.1 46.0 0.49 0.14 56 31 13 Silty sand Sandy loam 156 37 8.4 43.3 30.1 0.55 0.12 57 30 13 Silty sand Sandy loam 157 38 8.3 42.7 38.3 0.37 0.12 58 30 12 Silty sand Sandy loam 158 39 8.4 42.7 36.4 0.50 0.10 61 28 11 Silty sand Sandy loam 159 40 8.4 37.1 20.4 0.52 0.12 55 31 14 Silty sand Sandy loam 160 41A 7.9 27.0 6.3 9.06 4.93 56 40 4 Silty sand Sandy loam 161 41B 7.9 24.2 9.5 12.24 5.87 54 40 6 Silty sand Sandy loam 162 42 7.7 15.2 5.7 6.46 1.22 72 24 4 Silty sand Sandy loam 163 43 8.2 12.9 1.0 2.35 0.22 84 13 3 Silty sand Loamy sand 164 44 8.3 10.7 1.3 0.37 0.05 80 16 4 Silty sand Loamy sand 165 45 8.0 12.7 1.9 0.75 0.03 80 17 3 Silty sand Loamy sand 166 46 8.5 13.8 1.1 0.39 0.01 94 5 1 Sand Sand 167 47 7.9 9.6 3.3 0.49 0.20 29 64 7 Sandy silt Silt loam 168 48 8.1 9.0 3.0 0.37 0.12 32 60 8 Sandy silt Silt loam 169 49 7.8 8.2 2.8 0.45 0.91 15 81 4 Sandy silt Silt 170 50 8.2 12.9 5.1 0.44 0.11 34 62 4 Sandy silt Silt loam 171 51 8.0 50.6 2.1 0.23 0.05 93 6 1 Sand Sand 172 53 8.2 20.8 22.4 0.69 0.46 39 49 12 Sandy silt Loam 173 80 8.4 54.0 48.5 0.25 0.01 90 9 1 Silty sand Sand 174 82 8.2 48.9 40.8 0.87 0.24 57 34 9 Silty sand Sandy loam 175 140 7.1 23.9 9.6 13.90 8.31 54 45 1 Silty sand Sandy loam 176 141 7.0 21.1 6.8 23.60 12.29 43 53 4 Sandy silt Silt loam 177 142 7.4 24.5 6.5 16.30 13.73 70 29 1 Silty sand Sandy loam 178 143 6.9 22.2 8.3 16.90 11.74 31 68 1 Sandy silt Silt loam 179 144 7.5 22.2 7.0 6.50 3.99 71 28 1 Silty sand Sandy loam 180 145 7.4 22.5 8.1 8.70 4.15 67 32 1 Silty sand Sandy loam 181 146 8.4 26.5 20.5 2.30 1.60 50 48 2 Silty sand Sandy loam

APPENDICES

225

A-7: Lands applied for wastewater disposal at El-Dair (farmlands and ponds).


Sand(%)

Silt(%)

Clay(%) I II

182 94 6.4 16.3 2.1 30.40 6.09 77 21 2 Silty sand Loamy sand 183 95 7.3 32.6 6.9 4.70 0.50 97 2 1 Sand Sand 184 96 6.7 45.0 3.3 6.20 1.30 92 7 1 Sand Sand 185 97 7.1 27.6 6.6 21.00 4.57 73 24 3 Silty sand Loamy sand 186 98 7.6 18.0 2.0 5.70 1.09 98 1 1 Sand Sand 187 127 7.7 31.2 8.1 4.50 0.80 95 4 1 Sand Sand 188 128 7.6 13.2 6.8 7.50 0.69 94 5 1 Sand Sand 189 129 6.5 13.2 3.1 34.70 12.12 62 31 7 Silty sand Sandy loam 190 130 5.5 12.9 1.9 38.20 11.02 67 29 4 Silty sand Sandy loam 191 131 6.0 7.0 0.6 38.70 11.96 5 90 5 Silt Silt 192 134 7.2 25.9 9.9 17.80 3.66 79 16 5 Silty sand Loamy sand 193 135 6.4 18.8 6.0 21.70 12.85 21 59 20 Sandy silt Silt loam 194 136 7.9 27.0 8.5 12.60 2.14 83 12 5 Silty sand Loamy sand 195 137 7.2 26.4 9.6 6.00 3.16 68 28 4 Silty sand Sandy loam 196 138

Top

soil

laye

r

6.7 21.1 8.6 23.00 23.10 6 90 4 Silt Silt 197 94 6.5 1.3 0.2 3.20 0.43 96 3 1 Sand Sand 198 95 6.7 26.5 6.9 1.20 0.03 97 2 1 Sand Sand 199 96 6.9 58.5 4.7 6.20 0.64 95 3 2 Sand Sand 200 97 7.1 19.1 2.4 3.60 0.28 93 5 2 Sand Sand 201 98 7.2 32.6 1.8 2.90 0.22 98 1 1 Sand Sand 202 127 7.9 21.4 7.5 2.40 0.21 96 3 1 Sand Sand 203 128 7.9 37.1 5.4 3.50 0.22 98 1 1 Sand Sand 204 129 6.4 8.2 0.3 8.50 0.75 97 2 1 Sand Sand 205 130 7.4 74.2 7.3 3.70 0.69 94 5 1 Sand Sand 206 131 6.8 10.7 0.6 6.20 1.02 90 9 1 Sand Sand 207 134 7.6 44.4 6.0 2.30 0.26 96 3 1 Sand Sand 208 135 7.7 25.9 11.6 2.40 0.50 79 16 5 Silty sand Loamy sand 209 136 8.0 15.2 7.7 2.70 0.32 95 4 1 Sand Sand 210 137 8.1 33.2 15.2 0.90 0.18 84 15 1 Silty sand Loamy sand 211 138

F a

r m

l a

n d

s Su

bsoi

l la

yer

8.0 21.4 7.2 2.60 0.58 83 13 4 Silty sand Loamy sand 212 89 7.9 29.8 7.1 3.90 0.10 97 2 1 Sand Sand 213 90 7.2 25.9 7.9 12.40 1.38 93 6 1 Sand Sand 214 91 6.8 30.1 6.4 13.60 1.26 93 6 1 Sand Sand 215 92 7.8 27.8 8.3 11.90 2.10 91 8 1 Sand Sand 216 93 6.3 18.3 5.9 44.10 9.90 58 33 9 Silty sand Sandy loam 217 99 7.1 8.7 3.6 4.70 1.77 62 27 11 Silty sand Sandy loam 218 100 6.5 6.5 1.0 4.70 3.10 52 40 8 Silty sand Sandy loam 219 119 6.9 27.3 4.5 19.50 4.10 75 22 3 Silty sand Loamy sand 220 120 7.5 22.5 5.3 21.60 5.70 76 20 4 Silty sand Loamy sand 221 121 5.5 23.6 7.1 28.20 7.14 83 16 1 Silty sand Loamy sand 222 122 6.9 18.8 6.5 28.00 13.20 44 48 8 Sandy silt Loam 223 123 6.8 28.4 6.8 20.30 4.65 76 21 3 Silty sand Loamy sand 224 126 7.5 32.6 7.8 13.90 1.25 85 13 2 Silty sand Loamy sand 225 139 6.7 30.1 10.0 20.30 45.00 6 90 4 Silt Silt 226 155

Was

tew

ater

pon

ds

6.9 47.3 12.1 18.90 53.66 4 94 2 Silt Silt

APPENDICES

226

Appendix (B): Data of the soluble and available major cations and CEC values (meq/100g) in the examined sediments.

B-1: Cultivated floodplain (topsoil layer)

Soluble (ppm) Available (ppm) SN ID CaP

2+P MgP

2+P KP

+P NaP

+P CaP

2+P MgP

2+P KP

+P NaP

+P

CEC

1 1 58 26 28 100 5076 964 570 286 35 2 2 72 24 28 121 8036 1073 498 370 51 3 3 40 29 36 67 8229 1001 736 236 51 4 7 54 21 24 73 8482 1249 689 402 55 5 19 91 32 38 86 8348 1120 612 330 53 6 22 78 37 24 123 9550 2224 535 352 68 7 31 60 18 79 51 8007 984 955 176 50 8 32 67 22 51 68 8556 1112 805 250 54 9 33 57 24 17 61 8170 912 384 302 50

10 112 40 32 29 63 7918 1308 581 267 52 11 113 42 25 26 94 9105 1328 704 358 59 12 114 76 33 100 98 6060 944 1691 220 42 13 63 50 24 33 217 8007 1774 736 671 58 14 64 56 22 14 61 9328 1282 414 237 58 15 73 32 31 19 256 8586 1354 477 344 55 16 74 28 27 32 142 9075 1530 575 446 60 17 88 56 28 56 213 5712 999 581 396 38 18 102 156 40 62 131 7769 1282 743 277 51 19 103 95 36 34 115 8971 1477 500 369 58 20 104 59 24 17 33 8318 1057 385 205 51 21 105 72 23 66 109 7220 991 852 274 46 22 106 57 27 11 101 9476 2652 292 363 70 23 107 63 38 53 110 8793 2203 967 545 66 24 108 39 28 17 127 9476 1523 539 471 62 25 109 28 28 17 211 9921 2479 514 704 73 26 110 125 70 100 212 8942 1661 880 388 60 27 111 96 64 47 65 8140 1791 562 275 57 28 115 54 24 24 62 7651 1011 475 313 48 29 116 51 27 58 63 7888 1340 771 278 53 30 117 204 48 61 107 7947 1162 835 253 50 31 147 42 15 17 197 8628 1671 462 578 59 32 148 64 49 19 512 8526 2451 451 634 64 33 149 3029 1625 256 25100 11064 4847 757 27862 80 34 150 27 30 25 70 6060 649 334 138 36 35 154 274 69 33 145 8289 1425 442 218 53


APPENDICES

227

B-2: Reclaimed lands (topsoil layer)

Soluble (ppm) Available (ppm) SN ID CaP

2+P MgP

2+P KP

+P NaP

+P CaP

2+P MgP

2+P KP

+P NaP

+P

CEC

36 4 45 25 18 230 2400 573 204 404 18 37 5 287 38 20 844 8511 1452 342 1881 58 38 6 79 40 135 124 3900 999 1357 405 31 39 8 40 29 35 75 8586 600 723 349 50 40 10 799 3 21 1186 3012 692 156 3178 26 41 11 8683 1985 152 10200 11883 2753 269 11925 30 42 18 141 33 22 106 3840 718 213 226 25 43 20 78 26 18 83 3348 698 225 194 23 44 21 72 24 91 65 3744 917 941 276 29 45 23 54 22 18 56 6180 809 296 184 38 46 26 203 52 20 73 3324 901 209 168 23 47 28 75 22 145 206 2340 665 1077 413 20 48 54 16676 2247 682 8267 17280 4602 886 9244 28 49 55 723 319 126 449 3792 979 531 690 23 50 56 177 26 46 330 4440 978 555 503 31 51 57 41 25 23 70 6228 1131 361 286 42 52 58 112 56 55 740 5256 1074 463 1482 38 53 60 205 99 52 550 2580 897 356 1198 22 54 62 74 34 24 460 2604 878 252 861 22 55 65 103 39 12 284 4716 595 97 535 29 56 67 196 85 20 889 7027 1234 219 1467 47 57 68 64 39 12 528 5676 990 144 589 36 58 69 143 73 26 750 6120 1199 280 1122 41 59 70 174 83 25 891 3120 1042 296 1373 25 60 71 745 67 84 187 2580 225 338 248 11 61 72 238 90 69 1408 2400 680 461 2026 19 62 85 35 15 31 298 5520 937 467 440 37 63 87 136 58 39 465 4536 1506 540 608 36 64 101 51 19 26 42 3300 75 66 217 18 65 118 12 29 12 292 3432 1233 260 715 29 66 124 923 339 172 278 5220 976 450 755 29 67 125 118 34 50 125 4272 387 236 187 24 68 153 283 41 107 2770 2892 692 608 5120 30


APPENDICES

228

B-3: Wadi deposits Soluble (ppm) Available (ppm)SN ID

CaP

2+P MgP

2+P KP

+P NaP

+P CaP

2+P MgP

2+P KP

+P NaP

+P

CEC

69 9 1993 188 74 5382 7443 300 187 5866 31 70 12 3988 884 62 6121 6432 1361 128 6727 19 71 13 1468 172 144 1926 7452 316 400 2246 33 72 14 202 19 100 277 1896 131 385 360 10 73 15 1294 95 231 1518 2484 219 555 1877 9 74 16 273 30 184 328 1584 143 593 446 9 75 17 3655 128 266 1377 4320 207 713 2115 8 76 25 154 16 151 248 1620 106 470 306 9 77 27 182 18 79 154 1356 63 164 272 7 78 29 21588 2075 2303 5411 22968 2160 2811 5892 11 79 30 23612 3828 399 34500 24552 4111 536 36461 16 80 59 49 7 64 221 960 93 259 333 6 81 61 57 13 73 258 1092 78 293 385 7 82 66 144 19 37 144 4656 111 115 187 24 83 86 230 19 84 250 1620 90 231 615 9 84 151 2536 27 85 7500 4858 94 186 8857 18 85 152 1659 92 90 6105 4176 219 174 8208 23


B-4: Lands applied for wastewater disposal at El-Kola (ponds and wetlands) Soluble (ppm) Available (ppm)SN ID

CaP

2+P MgP

2+P KP

+P NaP

+P CaP

2+P MgP

2+P KP

+P NaP

+P

CEC

86 34 160 22 172 248 1620 104 442 341 9 87 35 1692 87 59 212 4404 167 163 488 16 88 36 1539 339 249 7718 8260 400 455 8710 39 89 37 395 117 95 389 2220 408 356 753 14 90 38 1779 210 105 333 5016 342 302 347 18 91 39 266 76 84 297 2340 373 352 467 14 92 40 266 83 94 236 2160 387 373 374 13 93 41A 340 47 71 303 4548 696 358 317 27 94 41B 460 50 72 318 5304 900 386 338 32 95 42 376 126 85 207 4392 656 287 278 25 96 43 58 29 28 254 3576 596 140 367 23 97 44 84 40 22 944 3960 833 136 1919 30 98 45 2021 588 37 4945 4680 1129 78 8005 31 99 46 112 40 11 800 1920 318 24 1267 13

100 47 148 61 53 310 8704 2232 643 809 64 101 48 671 248 50 1136 9150 2181 252 3305 68 102 49 2087 399 152 27705 11109 6069 415 28407 95 103 50 1190 739 76 10975 8526 2562 430 15557 72 104 51 471 162 7 707 3480 1102 20 1545 26 105 53 643 269 106 1525 4548 1459 611 2395 34 106 80 117 19 12 217 1416 116 43 314 8 107 82 1255 316 222 5410 3240 538 459 6368 17 108 140 1396 291 107 301 7844 914 382 468 39 109 141 1649 326 127 302 5040 793 427 677 23 110 142 1451 236 99 268 7354 588 376 459 34 111 143 1799 355 121 342 5820 757 477 731 26 112 144 1792 216 73 179 3900 377 239 419 13 113 145 1670 251 74 211 4272 435 385 403 16 114 146 3160 477 120 6951 10960 1138 271 9505 56

APPENDICES

229

B-5: Lands applied for wastewater disposal at El-Dair (farmlands and ponds) Soluble (ppm) Available (ppm) SN ID

CaP

2+P MgP

2+P KP

+P NaP

+P CaP

2+P MgP

2+P KP

+P NaP

+P

CEC

115 94 300 87 113 172 2652 378 285 352 15 116 95 83 13 21 36 2808 87 60 107 15 117 96 141 26 29 42 3672 121 42 192 19 118 97 210 78 49 96 3816 343 174 151 21 119 98 110 20 36 67 2520 190 159 151 14 120 127 80 28 52 91 780 135 164 225 5 121 128 92 30 75 108 2580 177 168 212 14 122 129 410 94 80 142 2964 626 615 266 19 123 130 485 171 173 90 3372 773 490 347 21 124 131 396 147 91 258 5628 1279 723 583 38 125 134 182 64 74 173 1560 353 349 345 11 126 135 803 373 201 308 5220 1080 934 839 32 127 136 301 104 97 338 1728 377 403 473 11 128 137 353 109 91 449 1920 341 344 583 11 129 138

F a

r m

l a

n d

s

1399 107 141 369 4440 654 599 587 22 130 89 87 11 48 70 1044 70 156 166 6 131 90 279 24 64 78 2484 149 160 182 13 132 91 164 38 62 96 2628 131 211 319 14 133 92 197 16 45 107 4356 189 207 136 23 134 93 1628 39 140 321 3564 669 385 523 16 135 99 190 24 55 111 4284 434 229 237 25 136 100 150 46 87 208 3540 602 406 302 23 137 119 280 104 126 229 3012 462 409 288 18 138 120 122 40 105 161 3096 433 364 296 19 139 121 459 304 307 364 1920 505 750 390 10 140 122 358 139 175 259 3792 795 530 389 24 141 123 144 91 263 237 900 422 588 421 8 142 126 310 15 50 87 852 159 182 176 5 143 139 2358 200 256 148 8472 1166 1782 4322 61 144 155

Was

tew

ater

pon

ds

2402 115 243 158 11772 1061 554 1017 59

APPENDICES

230

Appendix (C): Data of the total heavy metals content (ppm except for Fe) in the examined sediments

C-1: Cultivated floodplain (topsoil layer)

SN ID Fe% Mn Co Ni Cr Pb Zn Cu Cd 1 1 5.47 1085 33 62 138 16 125 57 0.88 2 2 6.87 1208 34 61 139 16 109 55 0.85 3 3 6.24 1138 31 62 145 24 131 60 0.87 4 7 6.44 1169 38 75 180 21 113 72 0.87 5 19 7.97 1521 36 72 118 21 131 71 0.89 6 22 7.74 2193 40 78 143 21 173 82 0.84 7 31 6.41 1204 34 56 146 20 130 55 0.76 8 32 7.46 1395 39 119 147 26 118 66 0.80 9 33 7.60 1353 39 84 159 18 191 68 0.77

10 112 8.16 1238 37 67 155 26 253 76 0.73 11 113 7.19 1420 36 67 152 19 223 81 0.78 12 114 4.14 1380 37 67 151 31 230 70 0.76 13 63 6.22 1186 37 64 120 23 133 65 0.66 14 64 7.38 1475 39 69 158 21 133 65 0.72 15 73 5.62 1149 30 64 130 23 98 69 0.79 16 74 6.40 1160 29 67 127 19 105 70 0.69 17 88 6.00 1393 35 65 100 23 204 79 0.91 18 102 6.58 1356 43 68 168 31 165 78 0.89 19 103 7.79 1419 41 73 145 28 163 80 0.78 20 104 6.72 1305 37 71 166 29 240 85 0.77 21 105 7.05 1243 37 68 153 29 246 73 0.77 22 106 6.42 1291 34 65 140 21 206 76 0.74 23 107 7.03 1400 34 70 119 23 166 78 0.70 24 108 6.38 1304 36 66 168 30 228 71 0.78 25 109 6.91 1696 39 70 115 23 149 75 0.76 26 110 6.62 1613 35 64 176 22 216 65 0.81 27 111 7.84 1461 34 66 171 34 201 65 0.78 28 115 3.71 604 15 54 134 52 1249 244 0.94 29 116 6.84 1341 39 69 192 24 180 68 0.75 30 117 6.92 1334 38 70 165 16 220 68 0.70 31 147 7.06 1141 36 66 145 22 156 69 0.64 32 148 6.53 1303 31 62 147 25 90 68 0.62 33 149 5.83 1375 26 51 131 21 136 66 0.69 34 150 6.85 1148 30 62 166 26 138 107 0.69 35 154 6.81 935 32 66 187 24 134 75 0.69


APPENDICES

231

C-2: Cultivated floodplain (subsoil layer)

SN ID Fe% Mn Co Ni Cr Pb Zn Cu Cd 36 1 6.41 1306 33 63 138 22 125 64 0.88 37 2 7.07 1289 35 61 155 17 135 54 0.81 38 3 5.79 1168 37 63 215 22 175 68 0.91 39 7 7.17 1269 40 68 154 21 116 69 0.88 40 19 8.46 1473 41 77 146 18 140 80 0.85 41 22 7.45 1885 41 84 144 18 115 84 0.84 42 31 6.84 1205 37 73 159 23 115 65 0.82 43 32 7.86 1519 41 73 180 18 138 75 0.84 44 33 7.66 1334 37 73 155 21 121 61 0.81 45 112 8.16 1395 40 73 200 19 190 83 0.75 46 113 7.22 1548 38 70 139 27 216 77 0.70 47 114 7.62 1474 39 68 169 28 153 73 0.77 48 63 7.63 1353 40 73 172 27 108 78 0.76 49 64 8.44 1483 43 72 150 21 108 74 0.73 50 73 6.54 1298 33 68 129 25 130 74 0.84 51 74 7.17 1315 35 67 113 23 113 73 0.77 52 88 4.95 1208 33 61 144 24 235 76 0.99 53 102 7.59 1398 44 73 151 21 195 77 0.89 54 103 8.20 1475 43 75 176 22 174 81 0.78 55 104 7.32 1365 36 69 190 26 146 82 0.68 56 105 7.66 1170 37 60 171 19 221 74 0.76 57 106 7.50 1323 40 74 184 17 214 79 0.73 58 107 7.86 1456 38 73 144 27 143 80 0.78 59 108 6.91 1409 38 69 141 22 168 79 0.78 60 109 7.24 1633 39 74 132 18 181 77 0.82 61 110 7.29 1263 36 70 170 28 146 73 0.81 62 111 8.40 1350 39 69 165 26 173 76 0.82 63 115 7.34 1436 38 63 149 22 469 80 0.76 64 116 7.49 1461 40 73 164 25 214 67 0.76 65 117 7.71 1386 38 71 190 22 119 76 0.73 66 147 7.16 1344 34 73 150 22 101 77 0.69 67 148 7.28 1433 32 54 173 25 99 69 0.75 68 149 6.68 1490 32 69 159 23 158 77 0.74 69 150 9.26 1273 31 64 156 26 148 80 0.67 70 154 7.67 1055 32 71 180 24 100 80 0.68


APPENDICES

232

C-3: Reclaimed lands (topsoil layer)

SN ID Fe% Mn Co Ni Cr Pb Zn Cu Cd 71 4 4.70 1011 30 45 116 21 115 51 1.12 72 5 7.31 1440 38 69 162 22 119 72 0.82 73 6 5.83 1294 36 64 147 20 145 59 0.87 74 8 12.30 1101 37 62 243 17 118 58 0.85 75 10 5.67 1493 40 69 134 22 175 59 1.00 76 11 6.39 1271 36 65 122 17 116 53 0.79 77 18 6.30 1443 35 67 175 22 123 61 0.75 78 20 6.16 1193 33 61 157 20 123 58 0.90 79 21 6.56 1308 38 68 202 27 115 72 0.97 80 23 6.54 1238 36 64 204 20 131 61 0.70 81 26 6.81 1268 37 68 173 31 89 68 0.82 82 28 5.59 1040 28 49 155 22 150 52 0.81 83 54 3.23 774 25 42 94 28 166 56 1.55 84 55 4.62 938 29 57 119 20 109 43 0.91 85 56 4.98 856 26 57 97 23 219 43 0.98 86 57 6.14 1299 33 68 121 23 106 70 0.86 87 58 7.12 1443 34 64 136 19 115 64 0.75 88 60 5.19 1113 28 60 126 25 101 53 0.86 89 62 6.66 1385 38 63 140 12 210 57 0.76 90 65 7.89 1409 37 78 139 14 156 69 0.75 91 67 7.13 1473 38 65 129 19 99 62 0.77 92 68 6.59 1310 35 66 120 16 106 59 0.84 93 69 6.09 1393 34 67 141 19 149 54 0.78 94 70 6.46 1309 35 57 138 26 144 63 1.38 95 71 3.00 694 24 73 135 47 401 75 1.50 96 72 5.41 1281 38 72 144 24 125 78 1.00 97 85 6.21 1335 38 61 179 21 273 81 0.84 98 87 8.94 1504 37 62 122 22 220 89 0.86 99 101 3.84 860 25 35 119 23 138 26 1.16

100 118 7.05 1531 39 73 182 17 178 72 0.68 101 124 1.75 3205 17 33 133 248 313 50 0.94 102 125 5.36 1503 34 55 128 38 175 59 0.85 103 153 5.47 948 25 58 145 28 126 59 1.02


APPENDICES

233

C-4: Reclaimed lands (subsoil layer)

SN ID Fe% Mn Co Ni Cr Pb Zn Cu Cd 104 4 3.00 526 26 38 77 27 100 33 1.80 105 5 7.05 1355 36 62 151 24 106 68 0.88 106 6 2.49 663 23 28 92 31 194 26 1.54 107 8 6.60 1203 38 69 160 21 120 65 0.86 108 10 3.82 1140 37 55 156 26 105 51 1.58 109 11 3.06 754 31 45 96 27 96 37 1.70 110 18 6.84 1338 35 62 171 20 190 56 0.93 111 20 3.95 905 28 45 151 28 113 36 1.45 112 21 7.84 1353 38 70 160 18 116 65 0.88 113 23 3.96 902 23 41 131 31 148 33 1.23 114 26 3.84 895 25 47 109 26 148 33 1.16 115 28 4.68 1013 25 40 127 21 125 40 1.11 116 54 1.70 541 23 31 113 30 141 115 2.00 117 55 5.54 1075 30 57 130 26 109 51 0.87 118 56 6.27 1148 30 56 200 24 111 57 0.76 119 57 5.20 1189 22 39 131 28 195 32 1.26 120 58 4.95 1206 26 40 165 26 95 34 1.02 121 60 5.10 1171 27 38 138 23 96 38 1.05 122 62 4.33 1298 29 44 151 31 91 35 1.14 123 65 4.07 1056 23 31 131 21 88 31 1.12 124 67 4.41 1124 27 36 163 27 138 40 0.94 125 68 3.37 805 24 37 125 35 126 31 1.37 126 69 2.00 549 24 28 87 36 165 35 1.88 127 70 3.88 709 33 48 150 35 194 53 0.73 128 71 3.94 639 28 44 102 27 99 45 1.33 129 72 3.06 883 21 30 107 26 134 25 1.39 130 85 5.31 1153 29 39 179 23 194 52 1.16 131 87 3.50 843 25 35 68 23 165 43 1.10 132 118 3.82 1059 29 39 96 22 275 34 1.17 133 124 3.76 1225 22 35 175 148 148 49 1.04 134 125 3.03 981 27 35 88 23 120 27 1.36 135 153 1.29 275 21 52 101 25 101 94 2.05


APPENDICES

234

C-5: Wadi deposits SN ID Fe% Mn Co Ni Cr Pb Zn Cu Cd 136 9 3.68 825 34 45 280 25 129 50 1.58 137 12 2.61 540 22 35 200 19 184 63 0.94 138 13 3.62 815 29 47 145 19 160 42 1.21 139 14 4.78 1121 31 49 143 31 156 66 1.27 140 15 4.84 923 30 48 150 31 181 70 1.31 141 16 5.6 1063 33 52 197 28 180 114 1.15 142 17 4.81 960 34 54 161 31 166 110 1.49 143 25 4.81 940 35 54 161 36 168 46 1.32 144 27 4.73 1139 32 49 133 29 164 54 1.19 145 29 2.95 846 22 34 64 23 81 32 1.30 146 30 3.62 815 29 47 100 19 195 42 1.21 147 59 3.37 726 28 43 108 33 160 40 1.77 148 61 5.94 1121 32 50 253 31 136 52 1.31 149 66 4.5 1024 31 48 150 27 148 39 1.18 150 86 4.14 1181 30 40 159 25 180 35 1.16 151 151 2.54 449 22 50 123 23 76 35 1.53 152 152 3.43 725 21 52 123 26 140 30 1.38


C-6: Lands applied for wastewater disposal at El-Kola (ponds and wetlands). SN ID Fe% Mn Co Ni Cr Pb Zn Cu Cd 153 34 4.77 940 33 51 171 31 194 65 1.32 154 35 1.87 584 27 35 111 32 113 72 1.90 155 36 3.50 550 30 42 95 33 151 72 2.00 156 37 3.16 778 31 48 102 29 170 109 1.41 157 38 3.56 894 36 49 129 31 145 185 1.52 158 39 4.82 790 37 53 156 28 2 00 93 1.65 159 40 4.37 769 33 47 139 30 144 76 1.40 160 41A 4.55 810 29 53 159 49 343 180 1.38 161 41B 3.72 846 31 59 156 55 343 116 1.43 162 42 4.08 764 31 59 137 38 645 92 1.08 163 43 5.29 1214 54 89 239 30 204 105 1.16 164 44 5.70 1204 47 82 209 31 181 125 1.00 165 45 4.90 1211 38 62 226 16 156 55 0.87 166 46 4.78 2368 38 59 176 25 151 112 0.98 167 47 5.77 913 38 79 296 23 125 84 0.91 168 48 7.00 995 46 90 256 26 173 94 1.00 169 49 2.40 863 37 74 190 24 143 87 0.84 170 50 5.92 1109 41 81 226 21 194 109 1.02 171 51 2.25 258 26 42 100 29 111 41 1.38 172 53 6.27 951 34 74 187 29 158 100 1.12 173 80 3.78 5418 37 102 105 32 128 91 1.85 174 82 3.49 699 30 46 85 29 150 67 1.72 175 140 5.86 858 25 108 205 171 659 267 1.12 176 141 4.94 783 23 123 244 176 718 338 1.16 177 142 5.70 850 26 109 206 154 794 211 1.11 178 143 4.00 784 21 106 195 148 628 206 1.14 179 144 6.26 894 28 87 185 165 531 173 1.11 180 145 6.19 841 26 93 213 157 598 180 1.18 181 146 3.39 758 23 35 93 59 168 46 1.15

APPENDICES

235

C-7: Lands applied for wastewater disposal at El-Dair (farmlands and ponds).

SN ID Fe% Mn Co Ni Cr Pb Zn Cu Cd 182 94 2.84 750 20 43 109 66 776 150 1.01 183 95 4.34 1159 26 36 155 27 225 44 1.21 184 96 2.41 1124 25 35 162 93 251 37 1.50 185 97 4.15 714 25 42 101 51 514 109 1.20 186 98 4.36 1074 26 39 179 26 176 55 0.86 187 127 3.77 884 27 39 177 38 214 50 1.03 188 128 2.54 1150 26 33 103 44 143 25 1.29 189 129 2.56 706 15 36 113 146 568 117 0.69 190 130 2.26 583 13 28 85 52 261 48 0.51 191 131 3.59 4213 17 50 139 186 1429 224 0.76 192 134 3.52 911 20 40 148 64 438 90 1.03 193 135 3.38 884 20 48 153 173 550 120 0.79 194 136 3.60 1009 20 36 160 68 266 61 0.87 195 137 4.69 880 24 40 131 44 258 61 0.95 196 138

Tops

oil

laye

r

3.80 775 19 59 114 143 868 206 0.89 197 94 6.49 1295 28 40 415 31 379 59 0.85 198 95 3.87 1281 28 36 167 23 120 42 1.23 199 96 1.47 1074 24 33 82 30 175 41 1.91 200 97 3.85 1421 30 40 132 28 229 46 1.08 201 98 3.96 1343 31 39 203 21 179 38 1.42 202 127 3.56 1041 28 27 153 37 194 36 0.95 203 128 6.69 1341 27 34 178 82 160 26 1.25 204 129 4.92 1095 23 37 191 57 328 31 0.54 205 130 1.15 482 20 20 65 56 165 17 2.11 206 131 3.68 909 22 38 300 58 486 57 0.70 207 134 3.18 690 23 27 171 39 149 35 1.41 208 135 4.30 1023 26 45 162 111 179 53 0.97 209 136 4.65 838 25 44 143 39 148 45 0.89 210 137 3.66 840 29 49 120 29 201 52 1.06 211 138

F a

r m

l a

n d

s Su

bsoi

l la

yer

5.11 1308 27 42 158 35 433 63 0.95 212 89 3.41 779 21 28 94 23 213 32 1.15 213 90 2.70 850 24 39 127 32 240 65 1.15 214 91 3.39 751 22 36 151 29 390 90 1.19 215 92 3.18 855 25 47 146 61 430 135 1.18 216 93 7.25 1341 38 67 222 263 165 86 0.85 217 99 7.03 1094 38 62 154 24 193 60 0.92 218 100 13.88 1030 39 60 170 23 209 68 0.88 219 119 1.98 1851 19 34 117 62 885 42 1.06 220 120 1.54 2434 18 29 98 42 326 41 1.02 221 121 2.34 765 17 41 107 67 319 62 0.93 222 122 1.35 2425 15 25 202 306 294 51 0.85 223 123 2.13 1436 19 28 123 131 263 47 0.99 224 126 3.35 814 24 43 119 61 536 71 1.10 225 139 5.90 557 21 52 141 205 900 175 1.40 226 155

Was

tew

ater

pon

ds

6.18 586 22 60 150 236 1040 223 0.86

APPENDICES

236

Appendix (D): Correlation coefficients of heavy metals, carbonate (CaCOB3B), organic matter (OM) and clay content throughout the various landuses.

D-1: Cultivated floodplain

Clay CaCOB3B OM Fe Mn Co Ni Cr Pb Zn Cu Cd Clay 0.20 0.37* 0.16 0.25 0.26 -0.02 -0.14 -0.11 -0.20 -0.24 -0.06

CaCOB3B -0.10 0.19 -0.18 -0.02 -0.10 -0.19 -0.20 -0.17 -0.20 -0.23 0.12

OM 0.38* 0.10 -0.12 0.00 -0.04 -0.25 -0.30 -0.03 -0.06 -0.01 -0.16

Fe -0.02 -0.57* 0.17 0.52* 0.61* 0.44* 0.19 -0.40* -0.50* -0.46* -0.22

Mn 0.05 -0.29 0.21 0.25 0.62* 0.34* -0.07 -0.35* -0.43* -0.43* 0.01

Co -0.09 -0.60* -0.09 0.38* 0.47* 0.52* 0.25 -0.42* -0.61* -0.64* -0.04

Ni 0.10 -0.53* 0.04 0.36* 0.53* 0.60* 0.11 -0.10 -0.22 -0.18 0.07

Cr 0.05 -0.18 -0.05 0.12 -0.26 0.13 -0.05 0.09 -0.05 -0.09 -0.11

Pb 0.15 0.27 0.02 -0.03 -0.20 -0.29* -0.20 0.01 0.78* 0.77* 0.27

Zn -0.13 0.07 -0.01 -0.11 0.06 0.14 -0.20 0.00 -0.09 0.94* 0.36*

Cu 0.37* -0.12 0.48* 0.32 0.35* 0.21 0.42* 0.06 0.08 0.22 0.31

Cd -0.17 0.37* -0.24 -0.54* -0.05 0.17 -0.08 -0.18 -0.21 0.06 -0.31

Upper half= topsoil layer (n=35), Lower half= subsoil layer (n=35).

D-2: Reclaimed lands Clay CaCOB3B OM Fe Mn Co Ni Cr Pb Zn Cu Cd Clay -0.47* -0.01 0.61* 0.20 0.34 0.21 0.27 -0.03 -0.02 0.45* -0.23

CaCOB3B -0.48* 0.22 -0.66* -0.39* -0.75* -0.41* -0.48* 0.16 0.43* -0.45* 0.68*

OM -0.02 -0.17 -0.49* 0.71* -0.59* -0.40* -0.10 0.95* 0.61* -0.06 0.16

Fe 0.59* -0.85* 0.05 -0.08 0.73* 0.52* 0.58* -0.49* -0.40* 0.39 -0.52*

Mn 0.24 -0.80* 0.22 0.83* -0.01 -0.14 0.09 0.78* 0.23 0.14 -0.36*

Co 0.69* -0.48* -0.11 0.68* 0.49* 0.71* 0.45* -0.57* -0.37* 0.55* -0.51*

Ni 0.77* -0.49* -0.01 0.71* 0.43* 0.82* 0.34 -0.50* -0.12 0.64* -0.37*

Cr 0.24 -0.52* 0.30 0.68* 0.70* 0.44* 0.49* -0.09 -0.12 0.33 -0.38*

Pb -0.21 0.05 0.91* -0.17 0.07 -0.27 -0.21 0.19 0.48* -0.13 0.11

Zn -0.19 -0.17 0.08 -0.06 -0.01 -0.09 -0.20 -0.11 0.07 0.20 0.36*

Cu 0.41* 0.07 0.12 0.05 -0.15 0.22 0.42* 0.21 0.00 -0.10 -0.12

Cd -0.40* 0.85* -0.19 -0.81* -0.76* -0.45* -0.44* -0.62* -0.03 -0.09 0.16


APPENDICES

237

D-3: Wadi deposits (n=17) Clay CaCOB3B OM Fe Mn Co Ni Cr Pb Zn Cu Cd Clay

CaCOB3B -0.44*

OM 0.37 -0.46*

Fe -0.05 -0.32 -0.50*

Mn -0.15 -0.42* -0.22 0.83*

Co 0.00 -0.26 -0.50* 0.78* 0.69*

Ni 0.07 -0.58* 0.05 0.58* 0.25 0.51*

Cr -0.10 0.05 -0.54* 0.41* 0.19 0.49* 0.14

Pb -0.28 0.29 -0.59* 0.64* 0.47* 0.57* 0.51* 0.14

Zn 0.27 -0.34 -0.32 0.39 0.35 0.43* 0.15 0.16 0.10

Cu 0.49* -0.30 -0.30 0.55* 0.29 0.45* 0.35 0.33 0.27 0.41*

Cd -0.06 0.69* -0.21 -0.14 -0.26 0.08 0.24 -0.05 0.41* -0.42* -0.12

D-4: Lands applied for wastewater disposal (ponds and wetlands). Clay CaCOB3B OM Fe Mn Co Ni Cr Pb Zn Cu Cd Clay 0.40* -0.41* -0.18 -0.27 0.15 -0.50* -0.30 -0.47* -0.47* -0.28 0.46*

CaCOB3B -0.73* -0.21 -0.62* 0.10 -0.37* -0.48* -0.81* -0.14 -0.27 -0.21 0.93*

OM 0.20 0.07 0.19 -0.17 -0.57* 0.63* 0.29 0.85* 0.90* 0.85* -0.18

Fe 0.52* -0.44* -0.23 0.04 0.32* 0.59* 0.74* 0.33* 0.33* 0.35* -0.52*

Mn 0.42* -0.35 0.36 -0.35 0.28 0.29 -0.07 -0.14 -0.18 -0.07 0.16

Co 0.62* -0.57* -0.16 0.83* -0.26 0.02 0.38* -0.61* -0.52* -0.37* -0.23

Ni 0.48* -0.21 0.06 0.78* -0.46* 0.81* 0.67* 0.67* 0.64* 0.71* -0.43*

Cr 0.67* -0.36 0.44* 0.45 0.14 0.50* 0.51* 0.27 0.29 0.38* -0.73*

Pb 0.33 0.21 0.71* -0.02 0.22 -0.14 0.17 0.65* 0.88* 0.82* -0.18

Zn -0.29 0.68* 0.05 -0.08 -0.21 -0.35 0.11 -0.16 0.28 0.78* -0.26

Cu -0.15 0.56* 0.08 0.27 -0.53* 0.04 0.54* 0.23 0.43* 0.69* -0.19

Cd -0.55* 0.34 -0.32 -0.26 -0.39 -0.29 -0.24 -0.44* -0.30 0.29 0.19

Upper half= ponds and wetlands at El Kola (n=29), Lower half= ponds al El Dair (n=15).

APPENDICES

238

D-5: Lands applied for wastewater disposal (farmlands) at El-Dair. Clay CaCOB3B OM Fe Mn Co Ni Cr Pb Zn Cu Cd Clay -0.26 0.32 -0.06 0.01 -0.41* 0.32 0.04 0.66* 0.25 0.30 -0.43*

CaCOB3B -0.06 -0.69* 0.22 -0.34 0.61* -0.18 0.49* -0.38 -0.49* -0.47* 0.69*

OM -0.11 -0.10 -0.44* 0.29 -0.89* 0.22 -0.61* 0.61* 0.71* 0.67* -0.66*

Fe 0.03 -0.72* -0.08 0.09 0.47* 0.39 0.42* -0.25 -0.02 0.07 0.05

Mn 0.23 -0.49* 0.00 0.60* -0.14 0.32 0.17 0.47* 0.68* 0.49* -0.10

Co 0.14 -0.34 -0.48* 0.41* 0.76* -0.09 0.48* -0.58* -0.50* -0.49* 0.80*

Ni 0.44* -0.59* -0.16 0.48* 0.39 0.48* 0.05 0.60* 0.73* 0.85* -0.12

Cr -0.08 -0.69* 0.12 0.63* 0.33 0.11 0.24 -0.09 -0.23 -0.24 0.22

Pb 0.39 0.04 0.18 0.20 -0.17 -0.36 0.00 -0.01 0.76* 0.76* -0.37

Zn 0.20 -0.56* 0.43* 0.32 0.19 -0.15 0.27 0.61* 0.00 0.96* -0.32

Cu 0.55* -0.61* -0.19 0.33 0.32 0.30 0.75* 0.47* -0.14 0.59* -0.37

Cd -0.09 0.95* -0.13 -0.68* -0.33 -0.20 -0.59* -0.56* -0.14 -0.55* -0.54*


APPENDICES

239

Appendix (E): The principal component scores of the first two factors throughout the studied sediments.

E-1: Cultivated floodplain

Topsoil layer Subsoil layer SN ID Component 1 Component 2 SN ID Component 1 Component 2

1 1 -0.8432 0.3183 36 1 -0.4986 0.2634 2 2 -0.6448 0.3716 37 2 -0.7468 0.2845 3 3 -0.5816 0.2217 38 3 -0.9485 0.0460 4 7 -1.0279 0.0655 39 7 -1.0124 0.2172 5 19 -0.9688 0.0936 40 19 -1.4028 -0.0106 6 22 -1.2814 -0.1839 41 22 -1.2685 -0.0674 7 31 -0.6089 0.2986 42 31 -1.0398 0.1625 8 32 -1.4406 -0.1984 43 32 -1.2340 -0.0001 9 33 -1.1294 -0.0828 44 33 -0.9888 0.1538

10 112 -1.1421 -0.1968 45 112 -1.7750 -0.2145 11 113 -1.2016 -0.1401 46 113 -1.3487 -0.1317 12 114 -0.6091 -0.0927 47 114 -1.0853 -0.0166 13 63 -0.6775 0.1866 48 63 -1.4282 0.0076 14 64 -0.9940 0.0511 49 64 -1.2595 0.0826 15 73 -0.5315 0.1976 50 73 -0.8611 0.1334 16 74 -0.6772 0.1215 51 74 -0.7978 0.2053 17 88 -0.5626 0.1114 52 88 -0.2075 0.1523 18 102 -1.0962 -0.0265 53 102 -1.3165 0.0209 19 103 -1.1703 -0.0588 54 103 -1.3469 -0.1215 20 104 -0.9768 -0.2658 55 104 -1.2163 -0.1715 21 105 -0.8847 -0.1233 56 105 -1.1097 -0.0294 22 106 -0.9225 -0.0347 57 106 -1.2651 -0.1528 23 107 -1.0491 -0.0574 58 107 -1.6080 -0.0489 24 108 -1.0211 -0.1292 59 108 -1.3134 0.0165 25 109 -1.3728 0.0567 60 109 -1.5656 0.0121 26 110 -0.9130 -0.0431 61 110 -1.0905 0.0045 27 111 -1.0405 -0.1322 62 111 -1.4451 -0.0158 28 115 0.9473 -2.6247 63 115 -0.7098 -0.4060 29 116 -1.0370 -0.0912 64 116 -1.0477 -0.0917 30 117 -1.0002 -0.0740 65 117 -1.2745 -0.0527 31 147 -1.1037 0.0416 66 147 -1.3481 0.0008 32 148 -0.8124 0.1061 67 148 -1.0313 0.1230 33 149 -0.2612 0.1147 68 149 -1.0413 -0.0642 34 150 -0.5370 -0.2399 69 150 -0.8947 -0.0779 35 154 -0.8351 -0.0508 70 154 -1.1959 -0.0587


APPENDICES

240

E-2: Reclaimed lands

Topsoil layer Subsoil layer SN ID Component 1 Component 2 SN ID Component 1 Component 2 71 4 0.4021 0.7873 104 4 1.7006 1.5786 72 5 -1.0437 0.0961 105 5 -0.7768 0.2585 73 6 -0.5920 0.1651 106 6 1.5565 1.2145 74 8 -1.6616 0.0304 107 8 -0.8332 0.2158 75 10 -0.5584 0.3855 108 10 0.6130 0.9813 76 11 -0.5174 0.4175 109 11 1.2739 1.3806 77 18 -0.7955 0.0964 110 18 -0.5365 0.2068 78 20 -0.3801 0.3505 111 20 0.7817 0.9572 79 21 -0.9293 0.0475 112 21 -0.9373 0.1914 80 23 -0.8722 0.0485 113 23 0.8792 0.8251 81 26 -0.8401 0.1468 114 26 0.9435 0.9425 82 28 -0.1056 0.3449 115 28 0.6937 0.8294 83 54 1.0683 0.8306 116 54 2.0431 0.9719 84 55 0.0970 0.6336 117 55 -0.2823 0.3938 85 56 0.2816 0.5531 118 56 -0.3917 0.1758 86 57 -0.6240 0.2452 119 57 0.7509 0.7156 87 58 -0.7246 0.1770 120 58 0.4934 0.7380 88 60 0.0986 0.4270 121 60 0.5032 0.8279 89 62 -0.7989 0.3507 122 62 0.5405 0.6046 90 65 -0.9630 0.0708 123 65 0.8431 0.9960 91 67 -0.8976 0.2507 124 67 0.6019 0.7088 92 68 -0.7382 0.3225 125 68 1.0839 0.9890 93 69 -0.5750 0.2266 126 69 2.0131 1.4468 94 70 -0.3264 0.4038 127 70 0.3249 0.5003 95 71 1.2308 -0.1000 128 71 0.9550 1.1097 96 72 -0.5092 0.1537 129 72 1.2426 1.0865 97 85 -0.7734 -0.1636 130 85 0.2871 0.4899 98 87 -1.2169 -0.0625 131 87 0.7857 0.8777 99 101 0.9357 1.0107

100 118 -1.1205 -0.1110 132 118 0.6961 0.6925 101 124 1.2434 -2.0184 133 124 1.0157 -0.2858 102 125 -0.0991 0.1998 134 125 1.1520 1.2030 103 153 0.2049 0.3999 135 153 2.0874 1.1909


APPENDICES

241

E-3: Wadi deposits SN ID Component 1 Component 2136 9 0.5020 0.6964137 12 0.8093 0.4606138 13 0.4762 0.6847139 14 0.4008 0.5525140 15 0.5162 0.5247141 16 -0.0020 0.0361142 17 0.3037 0.3117143 25 0.2993 0.6438144 27 0.3696 0.6135145 29 1.1090 1.0493146 30 0.5122 0.7440147 59 1.4172 1.2188148 61 0.0832 0.4292149 66 0.4640 0.7408150 86 0.5871 0.7386151 151 1.3781 1.2082152 152 1.1496 0.9770

136-146 east of the Nile; 147-152 west of the Nile E-4: Lands applied for wastewater disposal at El-Kola (ponds and wetlands).

SN ID Component 1 Component 2153 34 0.3751 0.5123154 35 1.6903 1.2386155 36 1.3655 1.1909156 37 0.8352 0.5966157 38 0.6147 0.1386158 39 0.4473 0.7565159 40 0.4842 0.7105160 41A 0.7065 -0.8204161 41B 0.6978 -0.5719162 42 0.4665 -0.6849163 43 -1.0284 -0.2661164 44 -0.9035 -0.3060165 45 -0.4894 0.2083166 46 -0.4549 -0.1570167 47 -0.9206 -0.2075168 48 -1.2429 -0.2473169 49 -0.2806 0.0564170 50 -0.7581 -0.2334171 51 1.4197 1.2326172 53 -0.3946 -0.0036173 80 -0.1689 -0.0716174 82 1.1573 1.0623175 140 0.3480 -3.3346176 141 0.3791 -4.4014177 142 0.3779 -3.1509178 143 0.6779 -2.8488179 144 0.2745 -2.0827180 145 0.3218 -2.3426181 146 1.0751 0.5916

APPENDICES

242

E-5: Lands applied for wastewater disposal at El-Dair (farmlands and ponds).

SN ID Component 1 Component 2182 94 1.4992 -2.1374 183 95 0.7976 0.4825 184 96 1.4571 0.2503 185 97 1.2310 -0.9088 186 98 0.3788 0.1653 187 127 0.7244 0.3143 188 128 0.9759 0.6043 189 129 1.6125 -2.3756 190 130 1.5441 -1.0350 191 131 1.0923 -5.3351 192 134 1.1457 -0.8851 193 135 0.9811 -2.1738 194 136 0.9512 -0.3788 195 137 0.6969 0.1043 196 138

Tops

oil

laye

r

1.3232 -2.9567 197 94 -0.5564 -0.8226 198 95 0.6152 0.7274 199 96 1.9715 1.1337 200 97 0.4590 0.3983 201 98 0.6158 0.6366 202 127 0.6827 0.5420 203 128 0.6313 0.3572 204 129 0.2776 -0.3932 205 130 2.6874 1.5902 206 131 0.3660 -0.8773 207 134 1.3391 0.8751 208 135 0.6039 -0.0929 209 136 0.4309 0.3703 210 137 0.6943 0.6060 211 138

F a

r m

l a

n d

s

Subs

oil

laye

r

0.3799 -0.1483 212 89 1.2231 0.8011 213 90 1.0944 0.0774 214 91 1.2318 -0.3375 215 92 1.0754 -0.8562 216 93 0.1864 -2.9173 217 99 -0.5907 0.1058 218 100 -1.3169 -0.0917 219 119 1.5438 -1.2721 220 120 1.2931 -0.4953 221 121 1.5234 -0.8659 222 122 1.6153 -2.5644 223 123 1.5218 -0.7619 224 126 1.2505 -0.5964 225 139 1.5660 -2.8314 226 155

Was

tew

ater

pon

ds

1.4532 -3.6209

APPENDICES

243

Appendix (F): Data of the bioavailable heavy metals content in the examined sediments (ppm).

F-1: Cultivated floodplain

SN ID Fe Mn Co Ni Cr Pb Zn Cu Cd 1 1 16.00 102.30 1.50 0.96 0.020 1.14 0.84 2.50 0.026 2 2 27.60 100.20 1.78 1.21 0.096 0.96 0.77 2.04 0.016 3 3 15.30 23.27 0.46 0.75 0.034 1.40 1.16 3.60 0.029 4 7 24.70 77.66 1.10 1.04 0.060 1.40 0.81 4.10 0.019 5 19 28.00 70.72 0.98 1.21 0.064 1.10 1.40 4.36 0.024 6 22 21.80 76.70 0.78 0.91 0.074 0.56 1.35 4.04 0.027 7 31 25.20 103.50 1.66 0.94 0.054 0.90 1.23 2.62 0.024 8 32 25.60 80.39 1.20 1.10 0.098 0.70 1.02 3.28 0.023 9 33 28.10 55.54 0.96 1.01 0.084 0.74 0.93 4.34 0.018

10 112 29.20 88.08 1.16 0.94 0.138 0.92 1.01 4.40 0.024 11 113 20.20 54.77 0.62 0.86 0.042 1.06 1.40 4.10 0.027 12 114 27.10 104.90 1.64 1.15 0.044 0.74 1.89 3.42 0.021 13 63 16.40 114.60 1.38 1.01 0.012 0.86 0.87 4.00 0.028 14 64 23.80 94.34 1.04 1.08 0.048 0.54 0.66 3.58 0.029 15 73 17.60 41.66 0.50 0.66 0.154 1.28 0.83 3.92 0.027 16 74 16.50 44.99 0.64 0.78 0.108 0.84 0.64 3.78 0.025 17 88 13.80 36.46 0.46 0.62 0.060 0.76 0.66 2.36 0.023 18 102 23.20 56.04 0.74 0.91 0.020 0.90 0.80 4.18 0.029 19 103 32.30 142.30 2.16 1.83 0.072 0.84 1.32 4.62 0.027 20 104 19.70 35.06 0.60 0.91 0.110 1.76 0.72 3.84 0.027 21 105 11.90 21.97 0.46 0.62 0.016 1.14 0.68 2.82 0.022 22 106 22.90 136.80 2.22 1.48 0.106 0.74 0.61 4.52 0.027 23 107 18.80 141.80 2.22 1.32 0.070 1.00 1.61 4.72 0.026 24 108 18.30 44.50 0.58 0.70 0.080 0.56 0.50 3.48 0.023 25 109 19.60 53.17 0.50 0.82 0.030 0.54 0.45 3.72 0.022 26 110 15.10 86.88 0.76 0.59 0.040 0.52 0.65 2.86 0.021 27 111 15.60 30.42 0.40 0.65 0.034 1.06 1.14 2.18 0.022 28 115 21.20 42.70 0.64 0.66 0.044 1.52 1.56 4.82 0.023 29 116 16.80 48.72 0.66 0.87 0.003 0.84 1.44 3.70 0.025 30 117 13.60 23.39 0.50 0.78 0.088 1.06 1.34 2.18 0.024 31 147 12.20 17.92 0.34 0.84 0.114 0.92 0.63 2.52 0.023 32 148 17.90 58.16 0.74 0.84 0.044 1.04 0.49 3.64 0.022 33 149 3.20 54.44 1.04 1.68 0.214 2.08 0.96 3.64 0.057 34 150 19.97 62.77 0.84 0.82 0.052 0.76 0.72 2.28 0.024 35 154 13.20 18.14 0.40 0.89 0.040 0.78 0.79 3.04 0.023


APPENDICES

244

F-2: Reclaimed lands

SN ID Fe Mn Co Ni Cr Pb Zn Cu Cd 36 4 14.40 83.40 1.06 0.54 0.050 0.62 2.62 2.04 0.023 37 5 20.50 25.44 0.44 0.65 0.054 0.88 0.82 2.58 0.023 38 6 14.00 60.22 0.74 0.71 0.056 1.04 2.29 1.64 0.024 39 8 15.40 18.98 0.46 0.67 0.048 1.44 1.09 2.54 0.028 40 10 6.80 4.27 0.38 0.44 0.070 0.90 0.28 1.10 0.024 41 11 5.40 11.29 1.20 1.64 0.306 3.38 0.68 0.94 0.083 42 18 11.30 19.79 0.52 0.44 0.116 0.88 0.48 0.58 0.023 43 20 19.10 28.51 0.46 0.47 0.052 1.44 1.30 1.96 0.024 44 21 28.60 102.80 1.72 1.19 0.022 1.22 1.77 3.72 0.024 45 23 25.90 65.35 1.10 0.79 0.046 0.76 0.69 1.92 0.015 46 26 10.70 15.19 0.48 0.53 0.090 0.88 0.63 0.90 0.022 47 28 23.00 103.40 1.40 0.86 0.058 1.04 1.81 2.68 0.022 48 54 48.60 117.60 1.92 2.11 0.440 6.16 5.76 1.66 0.112 49 55 13.20 71.52 1.18 0.87 0.104 0.90 1.13 1.58 0.030 50 56 18.40 62.09 1.20 0.93 0.094 1.06 1.56 2.18 0.025 51 57 25.20 41.35 0.64 0.49 0.110 0.74 0.43 2.86 0.023 52 58 19.20 50.75 0.60 0.69 0.130 1.06 1.44 2.88 0.022 53 60 26.20 90.49 1.12 0.76 0.056 0.82 1.76 2.76 0.027 54 62 15.00 63.85 0.78 0.60 0.050 0.48 0.55 1.68 0.023 55 65 14.00 26.92 0.52 0.55 0.122 0.28 0.34 1.48 0.020 56 67 13.60 41.06 0.58 0.62 0.078 0.70 0.44 2.20 0.024 57 68 18.50 77.84 0.90 0.59 0.072 0.80 1.02 1.94 0.021 58 69 16.70 65.87 0.76 0.64 0.132 0.84 0.75 2.16 0.020 59 70 20.80 44.51 0.62 0.76 0.044 2.16 1.34 3.60 0.026 60 71 197.50 53.28 0.72 1.10 0.072 5.48 23.07 6.58 0.034 61 72 13.40 41.54 0.64 0.69 0.126 0.94 1.55 2.92 0.026 62 85 18.20 31.40 0.52 0.57 0.050 2.16 3.57 3.54 0.024 63 87 15.90 41.72 0.46 0.71 0.082 1.42 0.77 3.62 0.028 64 101 23.30 8.20 0.24 0.19 0.054 0.72 0.41 0.14 0.017 65 118 28.50 269.00 3.06 1.88 0.082 1.10 1.47 2.52 0.213 66 124 463.80 166.70 0.12 4.04 0.092 0.40 0.89 0.28 0.015 67 125 22.90 74.57 0.54 0.62 0.046 1.14 1.35 1.40 0.018 68 153 23.80 163.50 2.00 1.61 0.176 0.92 1.72 5.68 0.028


APPENDICES

245

F-3: Wadi deposits SN ID Fe Mn Co Ni Cr Pb Zn Cu Cd 69 9 5.40 2.54 0.42 0.55 0.134 1.06 0.21 1.06 0.031 70 12 9.00 32.09 1.04 1.03 0.136 2.28 0.78 0.98 0.052 71 13 8.50 32.95 0.93 0.76 0.154 2.17 0.74 1.18 0.176 72 14 11.90 17.83 0.48 0.40 0.090 0.64 0.55 0.94 0.017 73 15 15.70 7.46 0.50 0.49 0.088 1.18 0.50 1.20 0.028 74 16 10.30 14.78 0.52 0.52 0.070 1.00 0.43 0.94 0.195 75 17 12.30 33.16 0.78 0.78 0.098 1.54 0.97 1.74 0.037 76 25 5.90 4.16 0.34 0.31 0.130 0.58 0.31 0.70 0.015 77 27 5.80 4.63 0.22 0.19 0.088 0.96 0.39 0.44 0.015 78 29 10.10 144.70 2.44 2.31 0.518 9.18 7.88 3.40 0.164 79 30 8.50 32.95 2.20 1.34 0.476 5.70 1.68 1.74 0.176 80 59 5.90 3.23 0.28 0.38 0.106 0.56 0.27 0.30 0.020 81 61 8.50 3.82 0.28 0.40 0.040 0.60 0.28 0.16 0.018 82 66 11.80 5.93 0.30 0.37 0.020 0.64 0.33 0.24 0.017 83 86 9.80 4.86 0.28 0.26 0.060 0.46 0.57 0.42 0.020 84 151 6.80 1.66 0.44 0.57 0.110 1.12 0.40 0.76 0.031 85 152 11.60 2.27 0.48 0.47 0.304 0.74 0.16 0.46 0.024


F-4: Lands applied for wastewater disposal at El-Kola (ponds and wetlands). SN ID Fe Mn Co Ni Cr Pb Zn Cu Cd

86 34 6.90 4.58 0.28 0.30 0.118 0.26 0.23 0.68 0.014 87 35 5.60 6.65 0.40 0.33 0.070 1.20 0.34 0.62 0.026 88 36 4.30 8.63 0.72 0.77 0.158 1.94 1.01 0.84 0.047 89 37 46.80 62.36 0.62 0.41 0.074 1.10 0.93 1.40 0.021 90 38 41.40 47.52 0.54 0.35 0.052 1.34 0.73 1.44 0.021 91 39 44.20 55.16 0.54 0.31 0.074 1.12 0.78 7.62 0.021 92 40 49.20 51.04 0.52 0.40 0.064 0.88 0.60 3.32 0.019 93 41A 397.30 64.26 1.12 2.45 0.102 2.92 26.63 1.78 0.026 94 41B 257.40 81.97 0.96 2.15 0.118 4.50 70.85 2.24 0.032 95 42 231.50 74.02 0.98 1.30 0.064 2.96 106.89 1.38 0.036 96 43 28.20 32.82 0.74 0.48 0.034 1.04 1.07 1.14 0.019 97 44 6.50 39.31 0.54 0.54 0.042 0.70 0.52 0.28 0.022 98 45 3.50 7.09 0.68 0.74 0.082 1.62 0.30 0.18 0.043 99 46 3.70 23.05 0.50 0.44 0.070 0.58 0.16 0.02 0.018

100 47 48.60 97.00 0.13 0.93 0.106 1.58 1.30 1.20 0.026 101 48 4.90 15.90 0.60 0.67 0.078 1.38 0.48 0.54 0.031 102 49 4.60 22.32 1.46 1.98 0.366 3.26 0.59 0.98 0.094 103 50 4.80 23.39 0.76 0.95 0.128 1.64 0.49 0.94 0.039 104 51 5.50 0.56 0.34 0.51 0.030 0.60 0.27 0.05 0.023 105 53 39.10 85.81 1.28 0.78 0.064 2.18 1.38 2.50 0.036 106 80 4.30 10.88 0.30 0.40 0.024 0.72 0.27 0.05 0.018 107 82 35.30 62.11 0.90 0.79 0.018 1.90 1.12 1.18 0.035 108 140 526.00 17.30 1.62 26.81 0.182 0.86 1.54 0.10 0.026 109 141 389.40 23.10 1.34 34.59 0.076 1.28 1.39 0.05 0.027 110 142 287.50 29.83 0.92 13.44 0.122 14.08 49.74 1.06 0.035 111 143 524.80 10.28 1.52 34.20 0.098 1.08 3.55 0.05 0.031 112 144 161.80 24.74 0.88 4.73 0.074 8.36 22.41 0.96 0.040 113 145 190.20 29.44 1.00 5.76 0.166 10.14 17.13 0.94 0.047 114 146 149.80 184.80 1.46 1.26 0.180 0.94 2.45 0.05 0.317

APPENDICES

246

F-5: Lands applied for wastewater disposal at El-Dair (farmlands and ponds) SN ID Fe Mn Co Ni Cr Pb Zn Cu Cd 115 94 311.7 51.82 0.36 1.01 0.234 9.20 15.15 2.92 0.035 116 95 25.4 9.91 0.20 0.21 0.074 0.68 1.98 0.36 0.015 117 96 47.0 23.88 0.22 0.21 0.092 1.38 4.35 0.78 0.015 118 97 281.2 42.11 0.50 0.76 0.134 2.36 37.33 0.80 0.015 119 98 68.0 19.20 0.20 0.27 0.104 1.10 8.42 0.70 0.016 120 127 66.6 13.26 0.20 0.21 0.058 0.56 3.92 0.24 0.012 121 128 32.9 36.74 0.20 0.32 0.046 0.40 0.68 0.18 0.010 122 129 767.4 47.50 0.72 1.93 0.048 1.62 39.56 1.32 0.036 123 130 522.3 46.21 0.44 1.18 0.086 0.84 4.02 0.22 0.017 124 131 482.7 67.23 0.75 3.12 0.096 2.01 38.76 1.53 0.133 125 134 433.8 37.97 0.34 0.85 0.062 2.30 43.40 1.42 0.016 126 135 706.5 46.53 1.59 3.41 0.026 0.90 2.47 0.18 0.032 127 136 283.9 60.66 0.36 0.50 0.030 0.88 7.02 0.22 0.195 128 137 107.2 53.03 0.40 0.62 0.074 6.34 81.33 3.00 0.023 129 138

F a

r m

l a

n d

s

878.3 26.28 0.99 4.17 0.142 4.29 25.70 0.54 0.344 130 89 170.4 12.05 0.42 0.51 0.102 0.64 1.17 0.30 0.017 131 90 101.9 16.52 0.24 0.33 0.074 1.68 6.89 0.70 0.015 132 91 99.9 16.94 0.28 0.36 0.018 2.48 11.23 0.78 0.015 133 92 124.5 15.12 0.34 0.54 0.084 4.90 15.68 2.52 0.023 134 93 403.4 18.54 0.74 2.40 0.106 1.58 21.96 1.02 0.036 135 99 199.8 89.66 0.90 0.83 0.048 1.64 6.52 1.86 0.018 136 100 191.1 87.84 0.96 0.93 0.018 2.46 10.04 1.58 0.024 137 119 367.0 58.92 0.52 1.03 0.174 2.18 193.88 0.44 0.021 138 120 375.9 45.66 0.30 0.72 0.118 1.22 10.23 0.54 0.019 139 121 118.1 49.99 0.50 1.02 0.120 2.90 10.25 0.42 0.016 140 122 571.8 49.45 0.68 2.17 0.138 0.68 1.92 0.34 0.023 141 123 261.2 59.90 0.28 0.75 0.198 1.54 15.28 0.92 0.010 142 126 320.9 28.66 0.28 0.56 0.058 1.62 55.41 0.20 0.015 143 139 776.0 30.47 1.47 5.72 0.190 1.98 68.27 0.39 0.045 144 155

Was

tew

ater

pon

ds

918.3 24.75 1.38 4.54 0.220 1.44 1.82 0.21 0.039

د

ARABIC SUMMARY

الملخص العربى

أ

الملخص العربى :عنوان الرسالة

الخصائص الجيوآيميائية لرسوبيات حوض النيل السطحية وعالقتها

.مصر، منطقة سوهاج، البيئية

سبة الى المحيط الحيوى وذلك ا بالن ا هام سطحية مكون تعتبر الرسوبيات الا ة یرجع الى آونها المستقبل و المرسل الجيوآيمي ئى الطبيعى للعناصر الكيميائي

درة ت ن ق ا م ا له ة وم ة نالمختلف ر لالغلف ك العناص ال تل ة انتق ى عملي ة ف ظيميوان ، نبات، ماء، هواء(المحيطة بها سان ، حي ة یو من ذلك ). ان تضح مدى اهمي

ر ة العناص ة و بخاص ر الكيميائي وث بالعناص ن التل ى االرض م ة عل المحافظوث ا صفتها المل ة ب م و الثقيل شكل دائ ة و ب طح الترب ى س صل ال ذى ی سى ال لرئي

.مستمر سواء آان ذلك بصورة طبيعية او نتيجة تدخل االنسان وانشطته المختلفة

يم ى تقي تهدفت ال ى اس ة والت ة الحالي ت الدراس رة آان ذه الفك الءا له واجث ن حي وهاج، م ة س ة لمحافظ ة والممثل ة الدراس ى منطق سطحية ف الرواسب ال

ا ة محتواه ر الثقيل ض العناص ن بع د(م ز، الحدی ت، المنجني ل، الكوبل ، النيكوم اص، الكرومي ك، الرص اس، الزن ادميوم، النح ستویاتها ) الك د م وتحدی

ى ا ف انى له ع المك ى التوزی رف عل ذلك التع ة وآ ستویات العالمي ا بالم ومقارنتهة المسئول ة و البيئي ل منطقة الدراسة و الكشف عن العوامل الجيوآيميائي ة عن مث

دة تخدامات االراضى المتواج ن اس ة م االنواع المختلف ا ب ع وعالقته ذا التوزی هة .بمنطقة الدراسة ومن ذلك یمكن التعرف على المصادر المختلفة للعناصر الثقيل

ة للحد من ة الممكن سبل العلمي شة ال ا البيئى ومناق فى منطقة الدراسة وتقييم اثره . لذلكت المناسبة ووضع التوصيامثل هذه السلبيات


ب

: فصول رئيسية وهىسبعةتتكون الرسالة فى محتواها العام على

:الفصل االول

م ة للتعرف على عل ة تمهيدی وهو یحتوى على الهدف من الدراسة و مقدموم أجيوآيمياء البيئة و ة و العل وم الجيولوجي هميته البالغة آحلقة وصل ما بين العل

.البيئية

:الفصل الثانى منطقة الدراسة والوضع الطبقى للصخور جيولوجية عن ویحتوى على نبذة

ة الاألساسية ب االراضى استخداماتالتعرف على آذلك و ،المختلفة بها د و ،منطق قات تم االهتمام بدراسة ال ع ساسية األنطاق ذات الصلة بموضوع لألراضى األرب

:الدراسة وهى ،نطاق السهل الفيضى -١ ،لحةنطاق األراضى المستص -٢ ،نطاق رواسب الودیان -٣ى -٤ اق األراض ستخدمةنط صرف الم اه ال ن مي تخلص م ة ال ى عملي ف

.الصحى

:الفصل الثالثى ة ف ة المتبع ذا الفصل الطرق المختلف ع ویعرض ه اتجم ة العين المختلف

ا ةوتجهيزه ات المعملي عللدراس ى م تخدمت ف ى اس وجزللطرق الت رض م ع وآذلك االجهزة ،محل الدراسة ت الكيميائية استخالص وتقدیر العناصر والمكونا

.واالدوات المستعملة


ج

: على النحو التالىالمعمليةالحقلية والدراسات يمكن ايجاز ودد -١ ع ع م جم ة ٢٢٦ ت سطحية بمنطق ل ال وبيات حوض الني ة لرس ة ممثل عين

.الدراسةدد -٢ ع ع م جم ستخدم ١٠ ت ى ت ى الت ى األراض ة ف اه الجوفي ن المي ات م عين

.للتخلص من مياه الصرف الصحىات -٣ انيكى لعين صل ميك ل ف م عم وبيات ت صائص للت الرس ى الخ رف عل ع

. لها المختلفةالنسيجيةة -٤ دیر الخصائص الكيميائي م تق ية ت ات ( األساس ن الكربون وى م ادة ، المحت الم

فى الرسوبيات ذات االرتباط المباشر بنوعية وتوزیع العناصر الثقيلة )العضویة .حل الدراسةمة -٥ ة والمتاح ات الذائب ة الكاتيون دروجينى وآمي رقم الهي ن ال ل م دیر آ م تق ت

.تحدید السعة التبادلية الكاتيونية لهالبالعينات ة -٦ ات مع (Heavy metals) تم تعيين المحتوى الكلى من العناصر الثقيل للعين

.منهاتقدیر الجزء المتاح حيویا ات-٧ ل لعين م اجراء تحلي ا ت رات و االموني دیر الملوحة والنت ة لتق اه الجوفي المي

دیر ٠والعناصر الثقيلة ات بهدف تق ذه العين وجى له ل بكتریول م اجراء تحلي آما ت . المحتوى من بكتریا القولون الكلية وبكتریا القولون الباسيلية

:الفصل الرابع

م الحصو ى ت ة الت ائج الخصائص الفيزیوآيميائي رد نت م س ه ت ا وفي ل عليهات محتوى، الرقم الهيدروجينى ، النسيج( ر العضویة الكربون ادة ، غي محتوى الم

).السعة التبادلية الكاتيونية، العضویة

م الل ت ن خ ات م سيجية للعين صائص الن شة الخ ائج مناق ع نت ل توقي التحلي ,USDA( و )Folk et al., 1970( البيانية لكل من ات على الرسومالحجمىع،)1993 ة و ا م واد الطيني سبة الم ى ن ز عل انى لترآي ع المك ة التوزی ا بمنطق له

ة ين أن .الدراسة لما لها من تأثير مباشر وفعال على سلوك العناصر الثقيل د تب وقة ة بالمقارن ة الناعم المواد الطيني ة ب ادة غني ون ع ضى تك سهل الفي وبيات ال رس

.باألراضى األخرى التى ترتفع فيها نسبة المواد الرملية


د

ات شة محتوى العين ا تم مناق ذلك محتواه ر العضویة وآ ات غي من الكربونضویة ادة الع ن الم انى م ع المك ع توضيح التوزی ل من م ة لك ة الدراس ا بمنطق .ه

ان ب الودی ين أن رواس د تب ر توق ات غي ن الكربون سبة م ى ن ى أعل وى عل حتد سجلت فى رس ادة العضویة فق وبيات العضویة فى حين أن أعلى نسبة من الم

.األراضى التى تستخدم للتخلص من مياه الصرف الصحى

:الفصل الخامسسر ى والمي وى الكل ائج المحت شمل عرض نت اوی ى حيوی ة ف للعناصر الثقيل

ا یضم ائج آم ل االحصائى والتعليق على النت الرسوبيات السطحية وآذلك التحليصل عليه ائج المتح يح النت ة بتوض ة والخاص ومات البياني يح الرس ع توض ا م

انى ع المك االتوزی صر له ل عن ة لك رائط جيوآيميائي م خ ن خالل رس ة م بمنطق .الدراسة

ذا عه ود ارب ائج وج د اوضحت النت ة وق ات سحنات جيوآيميائي من المكون

والتى تعبر بوضوح (PCA)الكيميائية بينتها التحاليل االحصائية باستخدام تقنية :قة الدراسة اما طبيعية او تلوثيةعن مصادر العناصر الثقيلة فى منط

1- The clay trend

ت د والكوبل ة والحدی ة الناعم واد الطيني سحنة الم ذه ال ضم ه ،وت، وهذا یدل على أن المواد الطينية تتحكم بشكل آامل فى سلوك هذین العنصرین

ة المواد الطيني ة ب ات الغني ى العين ة ف سبة عالي ون بن ا یك ان وجودهم الى ف وبالتس ص ى .حيحوالعك د الطبيع و Geogenic أى أن التواج صرین ه ذین العن له

.العامل األساسى الذى یتحكم فى سلوآهما

2- The carbonate trend اط الوثيق وتضم هذه السحنة الكربونات غير العضویة والكادميوم وتعكس االرتب

دل ادميو ذلك لسلوك الكادميوم مع الكربوبات وی ر من الك م على أن الجزء األآبات تحتوى على ، یوجد فى صورة آربونات وبالتالى فان العينات الغنية بالكربون


ه

ادميوم فى Geogenicأى أن التواجد الطبيعى . .ترآيز مرتفع من الكادميوم للك .الرسوبيات الجيریة هو العامل األساسى الذى یتحكم فى سلوآه

3- Organic matter trend

ادة سحنة محتوى الم ذه ال العضویة باإلضافة إلى عنصرى الرصاص وتضم هك ك ، والزن ة ویعكس ذل ى منطق ضویة ف ادة الع ع الم صرین م ذین العن الزم ه تع من ، الدراسة ز مرتف ادة العضویة تحتوى على ترآي ة بالم أى أن العينات الغني

ى ود ف صرین موج ذین العن ز له ى ترآي ان أعل الى ف ك وبالت اص والزن الرصویدل ذلك . خدم للتخلص من مياه الصرف الصحى رسوبيات األراضى التى تست

ى أن وثى عل صدر تل ى م ود ال ك یع اص والزن ن الرص ر م زء األآب الجAnthropogenicمصاحبا لمياه الصرف الصحى .

4- Mixed trend

ز والكروم والنيكل سحنة عناصر النحاس والمنجني ذه ال سحنة ، وتضم ه ذه ال وهمما ، Anthropogenic والثالثةGeogenicتتوسط فى سلوآها السحنة األولى

ات المدروسة یدل على أن جزء من هذه العناصریرجع للتواجد الطبيعى فى العينة ، فى حين أن الجزء اآلخر یعود الى مصدر تلوثى وان آان ذلك بدرجات متفاوت

صر آلخر ر من ، من عن وثى أآث أثر بالمصدر التل صر النحاس یت الطبيعى فعن .سبة للمنجنيز والكروم والنيكلوالعكس صحيح بالن

:الفصل السادس

ساب ى ح تنادا ال ة اس ة الدراس ى لمنطق ع البيئ شة الوض ت مناق ه تم و فير ى غي ى االراض ستویاتها ف ة و م ر الثقيل زات العناص ة الترآي ملوث

)Background levels( ا ا عالمي سموح به صوى الم دود الق ا بالح ومقارنته)MAL(.


و

تخلص من ةدراس آما تم ایضا الوضع البيئى لالراضى المستخدمة فى الة الناجمة عن الدیر وتقييم مياه الصرف الصحى بمنطقتى الكوال و االخطار البيئي

. على االراضى والمجتمعات التى تحيط بهاذلك

ز ة من الترآي اع ملحوظ في محتوى الترب وقد أظهرت الدراسة وجود ارتفن العناصر الثق سر م ى والمي ك األراضي الكل ي ذل ا ف وقعين بم ال الم ي آ ة ف يل

د اظهرت حسابات المستصلحة ا )CEF( المتاخمة لها وق ذه االراضى تاثره له احتمال وصولها إلى مما یؤدى إلى بمستویات عالية من التلوث بالعناصر الثقيلة

اه السلسلة الغذائية عن طریق المنتجات الزراعية، آما دلت النتائج على تأثر الميصحيال صرف ال اه ال ة بمي شكل آبيرجوفي اع ب ى ارتف ا أدى إل الموقعين مم ب

ة ات النيتروجيني وى المرآب وم(محت رات واألموني ة ) النت ون الكلي ا القول وبكتيریاه الصرف الحى ووصولها وبكتيریا القولون الباسيلية، مما یؤآد على هجرة مي

ة زان الجوفى بالمنطق ى الخ ك ، ال ى ذل ب عل واء اویترت ى احت ة عل اه الجوفي لمية ات الحي ذلك الكائن ر العضویة وآ العدید من المرآبات الكيميائية العضویة وغي

د ان.الدقيقة المسببة لألمراض المختلفة اه ق ة والمي ات في الترب ذه الملوث راآم ه ت . على حياة اإلنسانسلبایؤدى إلى حدوث مشاآل بيئية خطيرة تؤثر

سلطات المح ى ال ب عل ه یج ذلك فان ذه ل ن ه تفادة م رار االس ذي الق ة ومتخ لي

ذه ة للحد من مخاطر ه الدراسات العلمية واتخاذ اإلجراءات والضوابط الالزمة على ، الملوثات ة والبيئي آذلك فانه من الضروري إجراء الدراسات الجيولوجي

دى د م صحي لتحدی صرف ال اه ال ن مي تخلص م تخدامها لل ع اس ع المزم المواق .صالحيتها لهذا الغرض

وهاجــآليه العلوم بس

محمد حسن محمد على :اسم الطالب الخصائص الجيوآيميائية لرسوبيات حوض النيل :عنوان الرسالة

.مصر، منطقة سوهاج، السطحية وعالقتها البيئية

جلنة االشراف:

أستاذ الجيولوجيا المساعد كلية العلوم بسوهاجعزيز عبد اهللا الـحـداد عبدال/.د -١

أستاذ جيوكيمياء البيئة المساعد كلية العلوم بسوهاجعدلى عبد العـزيز محمد عمر/.د -٢

أستاذ األراضـى المساعد كلية الزراعة بســـوهاجمحمـــــــد سليمان ابراهيم/.د -٣

لجنة فحص و تقييم الرسالة:

١- جامعة الزقازيق-كلية العلوم-أستاذ اجليوكيمياء مصطفى محمود سليمان./ د.ا )حمكم خارجى(

٢- جامعة جنوب الوادى-أستاذ اجليولوجيا ووكيل كلية العلوم بقناعباس محمد منصور./ د.ا )كم خارجىحم(

٣- جامعة جنوب الوادى-كلية العلوم بسوهاج-أستاذ اجليولوجيا املساعدعبد العزيز عبداهللا الحداد/ .د )حمكم داخلى(

٤- جامعة جنوب الوادى-كلية العلوم بسوهاج-أستاذ جيوكيمياء البيئة املساعدعدلى عبد العزيز محمد عمر/.د )حمكم داخلى(

٢٠٠٥: / /تاريخ المناقشة

الدراســـــات العليـــــا

أجيزت الرسالة بتاريخ ختم االجازة / /٢٠٠٥

موافقة مجلس الكلية/ /٢٠٠٥

موافقة مجلس الجامعة / /٢٠٠٥


א אא א

א מ :א

א א:א א א א .،،א

א :א

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מ١٩٩٨ :א

מ٢٠٠٥ :א


الخصائص الجيوآيميائية لرسوبيات حوض النيل السطحية

.مصر، منطقة سوهاج، وعالقتها البيئية رسالة مقدمه الى

جامعة جنوب الوادىآليه العلوم بسوهاج

א درجة الماجستير فى العلوم الجيولوجية

)جيولوجيا(

مقدمه من

)١٩٩٨جيولوجيا (بكالوريوس علوم

لجنة االشراف

محمد عمرالعزيزعدلى عبد ./ د أستاذ جيوآيمياء البيئة المساعد

قسم الجيولوجيا آلية العلوم بسوهاج امعة جنوب الوادىج

عبد العزيز عبداهللا الحداد./ د أستاذ الجيولوجيا المساعد

قسم الجيولوجيا آلية العلوم بسوهاج جامعة جنوب الوادى

محمد سليمان ابراهيم./د استاذ علوم االراضى المساعد

قسم االراضى و المياه آلية الزراعة بسوهاج جامعة جنوب الوادى

هـ١٤٢٦ – م ٢٠٠٥

m.sc.thesis_m.hassan

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