petroleum hydrocarbon fingerprints of water and sediment...

Research ArticlePetroleum Hydrocarbon Fingerprints of Waterand Sediment Samples of Buffalo River Estuary inthe Eastern Cape Province South Africa

A O Adeniji12 O O Okoh12 and A I Okoh13

1SAMRC Microbial Water Quality Monitoring Centre University of Fort Hare Alice 5700 South Africa2Department of Chemistry University of Fort Hare Alice 5700 South Africa3Applied and Environmental Microbiology Research Group Department of Biochemistry and MicrobiologyUniversity of Fort Hare Alice 5700 South Africa

Correspondence should be addressed to A O Adeniji adenijigokegmailcom

Received 9 February 2017 Revised 26 March 2017 Accepted 3 April 2017 Published 30 May 2017

Academic Editor Paolo Montuori

Copyright copy 2017 A O Adeniji et al This is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

Petroleum hydrocarbon status of the Buffalo River Estuary in East London South Africa was evaluated from January to May2016 Surface water and sediment samples were collected from five points in the estuary and extracted using standard methodsThe extracts were subsequently analyzed by gas chromatography-flame ionization detection Results showed that total petroleumhydrocarbon (TPH) varied from 765 to 477 120583gL in the water and 1259 to 1100mgkg in the sediments with mean values of14650 plusmn 2796 120583gL and 20981 plusmn 6382mgkg respectively Concentrations of TPH in the sediments correlated significantly withorganic carbon (OC) in both seasons TPH and OC levels were slightly lower in summer than in autumn in the two environmentalmatrices and the average amount of TPH in the water samples collected from all the sampling stations was generally lower thanthe EU standard limit of 300 120583gL However the levels in the sediments exceeded the EGASPIN target value (50mgkg) for mineraloil but were below the intervention value (5000mgkg) indicating a serious impact of industrial growth and urbanization on thearea although the n-alkane ratios and indexes used for source tracking revealed excessive flow fromboth natural and anthropogenicsources

1 Introduction

The presence of chemical contaminants in the coastal envi-ronments frommany anthropogenic sources is amajor threatto the marine water [1 2] Large amounts of these con-taminants through sewage petroleum spills municipal andindustrial discharges and automobile wastes and vehicularemission due to incomplete combustion of fossil fuels arepossibly carried by river runoffs through their estuaries intothe sea [3 4] Petroleum hydrocarbons are one of the majorpollutants which are frequently discharged into the coastalwater thoughnot usually regulated as hazardouswastes [5 6]Although they are naturally present in very low concentra-tion in the marine sediments larger amount comes frompetrogenic and pyrogenic sources [7ndash9] and bottom sedimentwhich is the habitat of many aquatic organisms is recognized

as a potential reservoir of the petroleum hydrocarbons in themarine environments posing risk of bioaccumulation [4 6]

Assessment of the physicochemical properties of thewater and sediment is also very important because thesequality parameters are capable of affecting the biologicalcharacteristics of the environmental matrices and are thebasis for judging the suitability of such water body for itsdesignated uses [10ndash12] Although some of these parametersmay have limited health significance international standardsnecessitate their determination [13] The physicochemicalcharacteristics of each n-alkane in water and sediment sam-ples will therefore depend on the source of contamination inthe environmental matrices [14]

Some studies recently conducted on the physicochemicalparameters of different water bodies across the globe werereported Among the qualities assessed are pH dissolved

HindawiJournal of Analytical Methods in ChemistryVolume 2017 Article ID 2629365 13 pageshttpsdoiorg10115520172629365

2 Journal of Analytical Methods in Chemistry

oxygen temperature turbidity conductivity total dissolvedsolids and total suspended solids [11 15 16] Analysis of sed-iments qualities has also been found very paramount beinga major site for organic matter decomposition Continuousaccumulation of pollutants due to biological and geochemicalmechanisms can be toxic to the sediment dwelling organismsand fish resulting in decreased survival reduced growth orimpaired reproduction and lowered species diversity Somerecent findings on quality parameters of sediment like pHelectrical conductivity moisture content organic carbon andorganic matter were also reported [17 18]

Buffalo River Estuary is the mouth part of the longBuffalo River that covers about 1287 km2 area before draininginto the Indian Ocean in the coastal city of East LondonThe river flows through some major towns (Bhisho KingWilliamrsquos Town Zwelitsha Mdantsane and East London)and industrial areas that cover almost 12 of its catchmentarea Three major tributaries that feed the Buffalo River withrunoffs raw sewage solid wastes and industrial effluentsare the Mgqakwebe Ngqokweni and Yellowwoods riversmainly from densely populated urban and agricultural areasof the province [19] Surrounding the estuary are the EastLondon harbour and other direct users like Sea Spirit FishMarket Vukani Petroleum BP South Africa Mercedes BenzSouth Africa Chevron (Pty) Ltd Engen and Total SouthAfrica among others First and SecondCreeks are instances ofinfluent rivers which contribute to the inflow of stormwatersewerage and domestic and industrial runoffs into theestuary [20]

Previous environmental studies in the area focused onthe physicochemical characteristics and microbial and heavymetal contamination of the environmental matrices [19]However no report is available yet on the petroleum hydro-carbonprofiles in both thewater and sediment compartmentsof the estuary which is the subject of this current study In thispaper we report on the petroleum hydrocarbon fingerprintsof water and bottom sediments of the Buffalo River Estuaryin the Eastern Cape Province South Africa

2 Materials and Method

21 Description of Study Area The Buffalo River Estuary(33∘021015840S 27∘551015840E) is the largest and one of themost importantriver estuaries in the Eastern Cape Province of South Africaand located in the Buffalo City Metropolitan MunicipalityEast London [19] It receives stormwater from the shippingactivities at the East London harbour industrial effluentsdomestic wastes urban runoff and vehicular emissions fromSteve Biko and Buffalo Bridges either directly or indirectlythrough its influent rivers

22 Cleaning of Glass Bottles and Sample Collection Amberglass bottles used for sample collection were washed with tapwater and detergent and rinsed with distilled water followedby acetone Calibration standards high performance liq-uid chromatographic (HPLC) grade solvents and analyticalgrade reagents used for this work were sourced from Merck(Germany) and Restek and Accustandard (USA)

Figure 1 Map of Buffalo River Estuary East London

Five (5) sampling locations on the Buffalo River Estuarywere chosen on the basis of the level of anthropogenic pres-sures (Table 1 Figure 1) Monthly sampling was undertakenbetween January and May 2016 mostly during the high tideexcept in February spanning through summer and autumnseasons Duplicate water samples were collected 100mmbelow the surface level from two points (about 5m apart)in each sampling location with precleaned 1 L amber bottlespooled together to obtain a representative sample [21] Theywere acidified to pH lt 2 using 6M hydrochloric acid (HCl)The sediment samples were however collected only from 4locations using Van Veen Grab sampler because the estuarysubstratum at E5 was rocky All the samples were transportedto the laboratory immediately on ice chest for analysis [2223]

23 Physicochemical Analyses of the Samples TemperaturepH electrical conductivity (EC) and total dissolved solids(TDS) of the aqueous samples were determined on-site usingHanna multiparameter probe (HI 98195) while turbiditydissolved oxygen and total suspended solids (TSS)weremea-sured using Hach instruments (Hach Company USA) [24]Sediment samples were analyzed for moisture organic car-bon and organic matter contents using gravimetric method[25 26]

24 Extraction of Petroleum Hydrocarbon from Surface Waterand Sediment Samples Exactly 500mL of water sample wasspiked with 1mL of 10 120583gmL 1-chlorooctadecane (COD)used as surrogate standard extracted thrice in a separatingfunnel with 20mL of n-hexane each time The extractswere pooled together dried with anhydrous sodium sul-phate (20 g) and concentrated to about 2mL using rotaryevaporator ready for column cleanup [25 27 28] Sedimentsamples were air-dried for 5 days Also 10 g aliquot of the air-dried sediment sample was blended with sufficient quantityof anhydrous sodium sulphate (Na

2SO4) to removemoisture

spiked with 1mL of 10 120583gmLCOD and extracted in a Soxhletextractor with 200mL of dichloromethane for 24 h Theextract was allowed to pass through a glass funnel containinganhydrous sodium sulphate and reduced to approximately2mL using rotary evaporator It was then solvent exchangedto n-hexane before the cleanup stage [25 29]

Journal of Analytical Methods in Chemistry 3

Table 1 Description of the Buffalo River Estuary

Study area Locations Latitude Longitude Depth (m) Description

Buffalo River Estuary

E1 330306∘S 278580∘E 240A shallow entry point of the Buffalo Riverwater into the estuary with pollution loadfrom major towns like King WilliamsTown Mdantsane and Zwelisha

E2 330279∘S 278630∘E 347An extension of the shallow part of theestuary surrounded by hills with greenvegetations

E3 330261∘S 278830∘E 444

Second creek the largest perennialstream that accumulates stormwaterrunoff and leachates fromWilsoniaindustrial area residential zones centralsewage treatment works and a closedsolid waste landfill site

E4 330243∘S 278907∘E 616

First creek this is another stream underSteve Biko Bridge that contributesnonpoint source pollution in the form ofsewerage stormwater vehicularemissions and domestic and industrialrunoff into the estuary The point is veryclose to the Sea Spirit Fish Market thatuses some fishing boats for its activities

E5 330233∘S 278935∘E 723This is the deepest sampling pointlocated very close to Yacht club underBuffalo Bridge

25 Silica Gel Cleanup and Separation The water and sed-iment extracts were transferred into a 10mm ID times 30 cmchromatographic column packed with 10 g activated silicagel slurry with about 2 cm anhydrous sulphate layer ontop The column was eluted with 20mL of n-pentane toobtain the aliphatic hydrocarbon fraction [30] The eluateswere concentrated to about 2mL with rotary evaporator andsolvent exchanged to n-hexane A control (blank) sample wastreated the same way as the real sample for quality assurance[25 31]

26 Gas Chromatography Analysis All the cleaned sampleextracts were analyzed using Agilent 7820A gas chromato-graph (GC) equipped with flame ionization detector andHP-5 fused silica capillary column (30m times 032mm ID times025 120583m film thickness) The carrier gas was helium at flowrate of 175mLmin and average velocity of 2947 cmsecExactly 1 120583L of the sample extract was injected in splitlessmode at 300∘CThe column temperature was held at 40∘C for1min and then increased at 7∘Cmin to 320∘C The detectortemperature was 300∘C [1 28]

The gas chromatograph was calibrated with n-alkaneworking standards prepared in the range of 005ndash20 120583gmLusing n-hexane as diluent Calibration curves were plottedand average response factor was generated with AgilentChemstation chromatography software for each analyte Thecurves were linear with correlation coefficients ranging from09846 to 09919The unresolved peaks were quantified usingthe response factor of nC15 in accordance with the method ofLuan and Szelewski [32] TPH was integrated with baseline-holding and peak sum slicing and then quantified as the sum

of concentrations of the n-alkanes that eluted from nC9 tonC36 and UCM Data analysis was done with the Agilentsoftware [14 32] while ANOVA and Pearson correlation wereperformed using IBM SPSS Statistics 20 with the level ofsignificance set at 001 [11]

Limits of detection (LOD) for n-alkanes were determinedfrom 8 replicate injections of a middle level calibration stan-dard [33 34] LOD was statistically calculated by multiplyingthe standard deviation of the instrument response by ldquo119905rdquo valueat 99 confidence level [35]

3 Results and Discussion

31 Physicochemical Properties of Buffalo River Estuary WaterMedium Table 2 shows the seasonal variation and the rangeof values obtained for the physicochemical analyses of waterfrom the five sampling locations in this study while Table 3demonstrates the Pearson correlation among the water qual-ity parameters

pH is an important indicator of water quality and pol-lution level in the aquatic environment It is closely linkedwith biological productivity [36]ThepHof thewater samplescollected in the study area ranged between 74 and 93The values recorded in summer were generally higher thanautumn However there was no significant difference in thepH values across the 5 sampling stations The South Africanpermissible limit for coastal and marine water is 50ndash80[37] and the EU target limit is 60ndash90 [38] The pH valuesrecorded in this studywerewithin the stipulated limits exceptin January in four of the five stations (91ndash93) A significantpositive correlation was observed between pH and other


Table 2 Monthly variation in the physicochemical parameters of the estuary water

Parameters Summer Autumn Range Total meanJanuary February March April May

pH 9152 877 7538 757 793 74ndash93 82 plusmn 07Temperature (∘C) 2189 2406 2036 2049 1742 17ndash25 21 plusmn 2Conductivity (120583Sm) 2929 2622 3291 3262 3787 2420ndash4017 3178 plusmn 480Turbidity (NTU) 5102 3937 4906 5115 4872 2290ndash10000 4786 plusmn 1958Salinity (PSU) 2629 2421 2704 2634 2774 2284ndash2910 2632 plusmn 169Dissolved oxygen (mgL) 719 3624 595 642 715 241ndash919 607 plusmn 162Total suspended solids (mgL) 993 1077 1123 1150 9213 133ndash44667 2711 plusmn 1751Total dissolved solids (mgL) 1889 1611 209 2106 1904 1350ndash2275 1920 plusmn 248

Table 3 Matrix of Pearson correlation among water quality parameters

pH Temp Cond Turb Sal DO TSS TDS TPHpH 1Temp 0888lowastlowast 1Cond 0560lowastlowast 0381 1Turb 0325 0317 0201 1Sal 0861lowastlowast 0864lowastlowast 0670lowastlowast 0245 1DO minus0032 minus0316 0405lowast minus0183 0047 1TSS 0037 minus0110 0162 0559lowastlowast minus0076 0020 1TDS 0451lowast 0391lowast 0835lowastlowast 0129 0717lowastlowast 0406lowast minus0003 1TPH 0046 minus0072 0354 0094 0043 minus0004 0333 minus0011 1Temp temperature Cond conductivity Turb turbidity Sal salinity DO dissolved oxygen TSS total suspended solids TDS total dissolved solids TPH totalpetroleum hydrocarbon lowastlowastCorrelation is significant at the 001 level (2-tailed) lowastCorrelation is significant at the 005 level (2-tailed)

parameters including temperature (119903 = 0888 119901 lt 001)conductivity (119903 = 0560 119901 lt 001) and salinity (119903 = 0861119901 lt 001) (Table 3) Reportedly higher pH values have beenlinked to high concentration of carbonate in the water body[16 35]

Water temperature is another priority quality indicatorthat plays a vital role in aquatic systems due to its abilityto cause mortality and as well influence the solubility ofdissolved oxygen needed by the aquatic lives [36] In thecurrent investigations temperature varied from 17 to 25∘Cin the water column Temperature was generally higher insummer than in autumn thoughwith no statistical differenceamong the sampling stations although all the values obtainedthroughout the study period fell within the South Africanthreshold limit of 15ndash35∘C [33] Temperature also correlatespositively with salinity (119903 = 0864 119901 lt 001) and TDS(119903 = 0391 119901 lt 005) as earlier reported but no correlationwith dissolved oxygen was observed [39]

Conductivity is defined as a measure of the ability of asolution to conduct electrical current through the water [24]It is usually higher in saline compared to freshwater systems[36] The conductivity of the estuary water varied from 2420to 4017 120583Sm (Table 2) It was generally lower in summer(mean = 2776120583Sm) than in autumn (mean = 3447 120583Sm)and showed a positive relationship with depth increasingas the depth increases A similar trend was observed in thesalinity There is no standard guideline set for the controlof conductivity in marine water although limits set for total

dissolved solids are sometimes used in its stead [40] Effluentor sewage discharge as well as dissolved ions from soil androcks are known to influence the values of conductivity andsalinity in the water column [41 42] Significant correlation(119903 = 0670 119901 lt 001) observed between conductivityand salinity as shown in Table 3 confirmed their positiverelationship pH also correlates positively with conductivity(119903 = 0560 119901 lt 001) as previously reported [39]

Total dissolved solids (TDS) value is a measure of inor-ganic and organic materials present in water of which saltforms the principal constituent [42] The TDS of the estuarywater ranged between 1350mgL and 2275mgL The trendwas similar to that of the conductivity where the values werehigher in autumn than in summer Although South Africaand EU do not have any target value for TDS in the coastaland marine water the results obtained were higher than10mgL set as target value for estuary and coastal water inthe Darwin Harbour region [43] TDS in this work correlatepositively with salinity (119903 = 0717 119901 lt 001) in agreementwith the report of Chigor et al [11] conductivity (119903 = 0835119901 lt 001) pH (119903 = 0451 119901 lt 005) temperature (119903 = 0391119901 lt 005) and dissolved oxygen (119903 = 0406 119901 lt 005)as shown in Table 3 A general increase in concentrationwas observed as the water depth increases [40] Waters withhighTDS cause cells to shrink disrupt organismsrsquomovementand make them afloat or sink beyond their normal rangeHigh TDS value indicates high alkalinity or hardness and canconsequently affect taste of the water column [40]


Table 4 Average concentration of hydrocarbons and sources diagnostic ratios in the estuary water (120583gL)Parameters Summer Autumn Range Total mean

January February March April MayTotal n-alkanes 7763 16137 6829 5347 17734 1546ndash32859 10538 plusmn 1701UCM 3123 4515 4536 0 15031 167ndash27871 6666 plusmn 1678TPH 10261 17424 10458 5347 29759 765ndash47707 14650 plusmn 2796C15ndashC19 (odd) 0 0 1661 0 1697 0ndash4433 672 plusmn 242C18ndashC22 (even) 0 082 521 473 1361 0ndash3345 488 plusmn 169C25ndashC35 7121 10838 277 654 8817 0ndash22893 5541 plusmn 1381LH 0 001 466 029 029 0ndash756 100 plusmn 040C31C19 0 0 0 0 553 0ndash1698 246 plusmn 111UR 030 032 045 0 068 0ndash141 035 plusmn 009

Dissolved oxygen (DO) is another important componentof aquatic system [16 36 41] It is ameasure of the level of freenoncompound (nonbonded) oxygen dissolved in the watercolumn [44] DO enrichment in surface water is permittedthrough atmospheric exchange However thermal or salinitystratification and anthropogenic activities involving organicmatters may result in DO depletion suppressing respirationand causing huge die-offs of recreationally indispensable fish[39 45] The results of the DO measured in the estuarywater ranged as 241ndash919mgL (Table 2) The least averageDO was observed in summer when the water temperaturewas the highest supporting an inverse relationship betweenthe two parameters as evidently revealed (Table 3) [36]Although there was no significant difference spotted betweenthe stations however a gradual increase was observed fromsummer to autumn and also as depth increases The min-imum requirement of dissolved oxygen in coastal water is4mgL [39] DO concentrations recorded in this study areawere higher than the standard limit in all the sites exceptonly once in summer when a lower value of 241mgL wasobtained at site E2 [46]

Turbidity and total suspended solids (TSS) are otherquality parameters with significant relationship Turbidityis a measure of water clarity or muddiness resulting fromthe collection of dissolved and suspended solids makinglight scattered and absorbed instead of being transmitted instraight lines [47] Elevated turbidity in waters is often linkedwith the likelihood of microbiological pollution [41] Thecurrent investigation had mean turbidity of 4786 plusmn 1958NTU for the estuary water in the range of 229ndash100mgLTurbidity was generally higher in autumn than in summerThe highest value of 100mgL was obtained at E3 (secondcreek) inMaywhen fresh industrial effluents were dischargedinto the estuary and the lowest was also recorded the samemonth at E5 (229mgL) There was a gradual decrease inturbidity values as the depth increases and from summer toautumn Turbidity recorded at the shallowest site (E1) wassignificantly different from the values obtained from the twodeepest sites E4 (119901 lt 001) and E5 (119901 lt 005)

Similarly significantly high TSS was recorded in May atE3 (447mgL)This could be attributed to the fresh dischargeof effluents sighted at the site during the time of samplingTotal suspended solids in the estuary generally ranged from

133mgL to 447mgL showing the same trend of decrease asthe water depth increasesThere was no significant differenceinTSS among the five (5) sampling pointsHigher turbidity inthe nearshore waters may be due to particulates arising fromclay and silts from shoreline erosion resuspended bottomsediment organic detritus from water discharges urbanrunoff industrial effluents and excess phytoplankton growth[24 47]

32 Levels of n-Alkanes and Total PetroleumHydrocarbons in Water and Sediment Samples

321 Quality Control The quality control study was carriedout by spiking surrogate standard into each water andsediment sample before extraction and the recoveries whichwere within the acceptable range of 40ndash140 were used forcorrecting the final concentrations of the analyte compoundsextracted Limit of detection obtained for the n-alkanesvaried from 006 to 013120583gL and the relative standarddeviations (RSD) were in the range of 361 to 832 [48 49]

322 Levels of Petroleum Hydrocarbons in the Water SamplesTotal petroleum hydrocarbons (TPH) in the surface waterof Buffalo River Estuary were evaluated in all the sam-pling points The results covering two seasons (summer andautumn) are summarized in Table 4 and spatial distributionof petroleum hydrocarbons in the water matrix is depicted inFigure 2 below

The TPH concentration in the study varied widely acrossthe 5 locations from 765 to 47707 120583gL The highest con-centration was observed at site E3 followed by sites E4 andE1 as shown in Figure 2 Among these sites E3 and E4which were the second and first creeks receive seweragestormwater and runoff from industrial (including GatelyWest Bank Hood Woodbrook and East London Harbour)as well as the residential and commercial areas in the EastLondon metropolis Site E1 was located at the entry point ofthe estuary where Buffalo River freshwater is discharged withpollution loads from some major towns like King WilliamsTown Zwelisha and Mdantsane Lowest concentrations ofTPH however occurred in sites E5 and E2 with seeminglyless anthropogenic activities [19 20] Depth may also havecontributed to the low concentration of TPH in site E5 [50]


Series 1

020406080

100120140160180

Mea

n co

ncen

trat

ions

(휇g

L)

E2 E3 E4 E5E1Sampling points

Figure 2 Spatial variation of TPH in the Buffalo River watersamples

No particular trend was observed in the distributionof TPH across the whole period of study Generally theconcentrations were lower in summer than in autumn asreported by Maktoof et al [51] This could be linked with thecollection of samples mostly during the high tide in autumncompared to summer [52] and also because larger amount ofpollutants are swept into water bodies in autumn as the levelof rainfall increases [53] The highest concentration whichwas recorded at site E3 in May was probably due to thefresh discharge of effluent at the time of sampling Statisticalanalyses however did not show any significant difference inthe TPH concentrations obtained across the stations Thetotal mean concentration of TPH (14650 plusmn 2796 120583gL) in allthe sites was lower than the EU acceptable standard limit forhydrocarbons (300 120583gL) in estuary and harbour basin water[38]

The level of water TPH from this study was significantlylower compared to values reported in some regions includ-ing Bohai Bay of China [54] Strait of Johor PeninsularMalaysia [55] seawater of North Cape [56] groundwatersamples collected from some communities in Rivers StateNigeria [57] surface water from Ubeji in Warri Nigeria[58] and the surface water from the neighbourhood of Nige-rian National Petroleum Corporations Oil Depot in ApataIbadanMetropolis Nigeria [59] However some studies werereportedwith lower values of TPH than obtained in this studyin other parts of the world Examples include water samplesfrom Main Outfall Drain in Al-Nassiriya CitySouthern Iraq[51] water samples from Setiu Wetland [60] Terengganucoastal waters from Malaysian west coast [55] and DungunRiver basin water Malaysia [23]

323 Levels of Petroleum Hydrocarbons in the Sediment Sam-ples In this study the concentrations of TPH in the estuarysediments expressed on dry weight basis are presented inTable 5 The values ranged from 1259 to 1100mgkg Asshown in Figure 3 site E1 recorded the highest concentrationof TPH followed by site E3 (second creek) while the lowestwas obtained from site E4 which could possibly be relatedto the higher depth of water at the station [50] However the

Series 1

0

50000

100000

150000

200000

250000

300000

350000

400000

450000

Mea

n co

ncen

trat

ions

(휇g

kg)

E2 E3 E4E1Sampling points

Figure 3 Spatial variation of TPH in the Buffalo River sedimentsamples

rocky substratum of site E5 made sediment sampling difficultthroughout the span of this study There was no doubt thatlarger contribution of pollutants in the estuary sediment wasfrom Buffalo River water discharge at E1 as well as the intro-duction of the industrial effluents and leachates from the oldland fill site at E3 among others [19 20] Notwithstanding thestatistical tests conducted revealed no significant difference inthe levels of TPH determined between the sampling stationsThe temporal distribution of TPH in the sediment follows thisorder April gt January gtMay gtMarch gt February (Table 5)Petroleum hydrocarbons in the sediments were found muchhigher in autumn with mean concentration of 23362mgkgthan in summer (16022mgkg) due to the upward push andresuspension of contaminants occasioned in some cases bythe high tidal forces in the aquatic environment [52 61]

Although no sediment guideline is in place for totalpetroleum hydrocarbons nevertheless four levels ofpetroleum hydrocarbon pollution were suggested for theassessment of marine sediments [50] They were unpolluted(10ndash15mgkg) slightly polluted (15ndash50mgkg) moderatelypolluted (50ndash200mgkg) and heavily polluted statuses(gt200mgkg) This was not entirely different from therespective target and intervention values of 50mgkg and5000mgkg set as environmental guidelines for soil andsediment TPH by the Department of Petroleum ResourcesNigeria [62 63] In light of the above the TPH concentrationsof the Buffalo River Estuary sediments were largely belowthe intervention value ranging from ldquomoderately pollutedrdquoin summer to ldquoheavily pollutedrdquo in autumn [50 64]

Petroleum hydrocarbon levels in the sediment compart-ment of this study area were found comparatively lowerthan those reported for the sediments from Ceuta harbourNorth Africa [65] and Arabian Gulf Kuwait [50] Howeverthe concentrations were a little higher than those from theArabian Gulf [66] Bohai Bay China [67] Khowr-eMusa Bay[22] and Musa Bay [68] Nonpolluted sediments reportedin some studies include those from coastal area of Putatanand Papar Sabah [69] Main Outfall Drain in Al-NassiriyaCity Southern Iraq [51] and coastline and mangroves of thenorthern Persian Gulf [70]


Table 5 Average concentration of hydrocarbons and sources diagnostic ratios in the estuary sediment (mgkg)


Total n-alkanes 5535 3845 2548 8902 3595 204ndash16989 4953 plusmn 998UCM 16843 5820 7568 39565 8448 270ndash93033 16028 plusmn 5419TPH 22378 9665 10116 48468 12043 1259ndash1100 20981 plusmn 6382C15ndashC19 (odd) 108 044 092 288 071 025ndash630 123 plusmn 031C18ndashC22 (even) 215 198 167 535 174 095ndash1116 262 plusmn 054C25ndashC35 4353 2926 1833 6360 1933 643ndash12712 3562 plusmn 790LH 015 008 008 007 017 004ndash032 011 plusmn 002C31C19 1450 2638 351 380 508 230ndash3529 1095 plusmn 233UR 153 154 319 382 219 027ndash577 247 plusmn 038CPI 300 299 194 168 152 114ndash411 226 plusmn 020ACL 2937 2937 2842 2892 2853 2738ndash3069 2894 plusmn 016UCM unresolved complex mixture TPH total petroleum hydrocarbon LH low molecular n-alkaneshigh molecular n-alkanes UR unresolved n-alkanesresolved n-alkanes CPI carbon preference index ACL average carbon chain length

Table 6 Percentage moisture organic carbon and organic matter contents of the sediments

Moisture () Organic carbon () Organic matter ()Range 4501ndash6786 312ndash894 539ndash1542Mean 5903 plusmn 685 614 plusmn 135 1059 plusmn 23233 TPH Relationship with Percentage Moisture Organic Car-bon and Organic Matter Contents of the Sediments Table 6shows the percentage moisture organic carbon (OC) andorganic matter (OM) of the estuary sediments The muddysediment samples contain a large percentage of water in therange of 4501ndash6786 with an overall average of 5903The sediment grains were relatively small having an averagecomposition of 5835 fine sand 3043 very fine sand and1122 coarse silt determined by sieving Both OC and OMinmuddy sediments were considered to play a significant rolein the accumulation and release of variousmicropollutants inthe aquatic environments [50]

Organic carbon in the sediment samples ranged from312 to 894 (mean = 614) whereas organic matter variedbetween 539 and 1542 (mean = 1059) Statisticalanalysis showed a significant difference (119901 lt 01) inthe moisture contents of the sediments collected from E2and E4 However no significant difference was observedamong the stations in relation to OC and OM The totalpetroleum hydrocarbon positively correlate with OC (119903 =0665 119901 lt 001) and OM (119903 = 0665 119901 lt 001)(Table 7) indicating a direct relationship among the threeparameters This relationship was further checked in a plotof OC against TPH The plot yielded a straight line with1199032 = 01043 (Figure 4) High concentration of petroleumhydrocarbons in the sediments of the river estuary testifies tothe role of sediment as a sink for organicmicropollutants [71]Petroleum hydrocarbons concentration is usually higher inmuddy sediments compared to the coarse ones establishinga strong relationship between grain size and TPH [50 72 73]

34 Hydrocarbon Source Identification UsingMolecular Mark-ers The use of n-alkanes as a molecular marker has

Table 7 Pearson correlations among the sediments quality param-eters

moisture OC OM TPHmoisture 1 OC 0316 1 OM 0316 1000lowastlowast 1TPH 0133 0665lowastlowast 0665lowastlowast 1lowastlowastCorrelation is significant at the 001 level (2-tailed)

been of great advantage in the identification of pollutionsources in the estuarine and marine environments [9] Manymathematical ratios and indexes like major hydrocarbon(MH) ratios of low molecular weight to high molecu-lar weight n-alkanes (LH) unresolved complex mixture(UCM) average carbon chain (ACL) carbon preferenceindex (CPI) weathering index and C31C19 have been usedto identify the origins of n-alkane in the environment [74 75]

341 Distribution of n-Alkanes Various ways through whichhydrocarbons come to the surface of marine and coastalwaters include anthropogenic activities biosynthesis (pro-duction of hydrocarbons by some living organisms in theaquatic environments) and geochemical processes (egseepage) Some anthropogenic activities involving indus-tries oil operations and urban undertakings could generatesubstantial quantity of hydrocarbons in the marine watersHowever hydrocarbons from biosyntheticmarine origins arealways present in trace quantity [9 74]

Concentrations of total 119899-alkanes in the estuary varybetween 1546 and 32859 120583gL in the water samples and from9889 to 169885 120583gkg in the sediment samples as shown inTables 4 and 5 Clear indication of different sources is offered


TOCLinear (TOC)

R2 = 01043

y = 00184x + 57095

0

10000

20000

30000

40000

50000

60000

70000

80000TO

C (휇

gkg

)

10000000 20000000 30000000 40000000000TPH (휇gkg)

Figure 4 Plot of TOC versus TPH in the water matrix of BuffaloRiver Estuary

by the strong presence of some specific normal alkanesExamples include nC25ndashnC35 which indicate biogenic input(terrestrial and vascular plants) and a strong dominance ofodd over even numbered n-alkanes could also suggest thesame originThe presence of nC15 nC17 and nC19 n-alkanesindicates inputs from phytoplankton and algae marine bio-genic sources Dominance of even carbon n-alkanes suchas C16 C18 and C20 indicate petroleum hydrocarbonspollution fromanthropogenic sources Likewise the presenceof nC12 and nC14 alkanes indicates microbial biogenic origin[27 76 77]

Distribution of n-alkanes in the study revealed that themost prominent ones in the water samples were nC9ndashnC12nC15 nC17 nC19 and nC26ndashnC36 whereas in the sedimentsamples nC10ndashnC12 nC18 nC20 nC22 and C22ndashnC36dominate Generally heavier hydrocarbons were more inabundance than the lighter ones and odd carbon n-alkanesseemed to be a little more dominant than the even carbon n-alkanes as was also reported by Ahmed et al [28] Aliphatichydrocarbons in the water compartment of the estuaryare principally from biogenic sources However the originsof the n-alkanes in the sediments are both biogenic andanthropogenic (possibly from fishing industrial stormwaterand urban runoff) [78]

342 Low Molecular WeightHigh Molecular Weight n-Alkanes (LH) Ratio of low molecular weight n-alkanes(C15ndashC20) to high molecular weight 119899-alkanes (C21ndashC34) isanothermarker being used for the determination of 119899-alkanessources [28 78] Low molecular weight hydrocarbon usuallydominates in a fresh oil release giving a ratio greater thanone LH is an indicator of the freshness of the hydrocarbonsreleased into the environments However fast degradationof these lower molecules in crude oil can decrease the ratiosignificantly to a value below unity The LH ratio below1 (unity) reveals natural input from marine and terrestrialbiogenic sources and ratios around and above 1 indicatehydrocarbons from petroleum sources [79 80]

The results obtained from the water samples showed theLH ratios greater than one (1) in the first two stations (E1and E2) indicating fresh release of petroleum hydrocarbonsfrom agricultural residential andor industrial activitiesthat entered the estuary through rivers and streams in thewatershed However the remaining three sampling locationsyielded ratios lower than one (unity) Sediments samplesfrom all the stations also gave LH ratios lower than 1suggesting hydrocarbons from natural sources [79]

343 Long Chain HydrocarbonsShort Chain Hydrocarbons(LHCSHC) Short chain hydrocarbons (SHC) are the n-alkanes which are below and up to nC26 (eg nC15 nC17and nC19) They are derived from planktonic and benthicalgal sources whereas long chain hydrocarbons (LHC) arethe n-alkanes up to nC26 (eg nC27 nC29 and nC31) whichare mostly from vascular plants sources They are known tobe more resistant to decomposition than their short chaincounterparts The ratio is used to evaluate the dominanceof vascular plant and phytoplanktons in the marine envi-ronments While the ratio of LHCSHC between 021 and080 indicates phytoplankton sources value in the range of238 to 433 suggests a mixture of both sources Higher valuegreater than 40 shows the dominance of terrestrial plantwaxes [78 81]

LHC = sum of nC27 nC29 and nC31SHC = sum of nC15 nC17 and nC19

Average LHCSHC ratio obtained in this study rangedbetween 1118 and 1771 in the 4 sediment stations an indi-cation of a significant input from terrestrial plant waxes

344 Unresolved Complex Mixture (UCM) and WeatheringIndex (WI) The UCM is considered a mixture of branchedand cyclic hydrocarbon structures including many of theirstructurally complex isomers which are unresolvable bythe capillary columns of gas chromatograph [74 80] Thealiphatic hydrocarbons are less soluble than the aromaticcompounds which are relatively more mobile in water Thebranched aliphatics are even less water-soluble than thestraight-chained alkanes Hence they concentrate more inthe sediment compared to the water column [5] AlthoughUCM are mostly present in the higher molecular rangeof the hydrocarbons few exist in the lower range as wellThe lower range UCM can easily be evaporated unliketheir counterparts in the higher range category and theirpresence in the marine environments generally indicatebacterial degradation of old petroleum products or chronicoil pollution however fingerprinting information availablefrom their data is very limited [9 14 82]

Figures 5 and 6 revealed the presence of UCM in someof the samples analyzed (mostly sediments) appearing as aunimodal or sometimes as a bimodal hump in the range ofnC12 to nC15 and nC22 to nC35 The UCM concentrationsin the sediments varied between 2700 and 930328 120583gkg(mean = 160278 plusmn 5419 120583gkg) and in the water samplesbetween 67 and 279120583gL (mean = 6666 plusmn 1678 120583gL)Meanwhile the abundance of the higher molecular weight


FID1 A front signal (115F1501D)

255075

100125150175200225

(pA

)

10 15 20 25 30 355(min)

Figure 5 Chromatogram of a typical sediment sample from E1


20406080

100

(pA

)

10 15 20 25 30 355(min)


hydrocarbons (gtnC23) over the lighter ones suggests norecent contamination in the aquatic environment [14 83]

Another useful tool employed for the assessment ofthe presence of some important crude oil residues is theratio of the unresolved components to that of the resolvedones (UR) otherwise called weathering index Higher ratiogreater than 4 is usually a criterion for important petroleumresidues [84] In this study UR in the sediment samplesgenerally ranged from 027 to 577 Higher ratios greater than4were observed only in autumn (March andApril) at stationsE1 and E3 suggesting pollution arising from the inflow ofurban and industrial runoffs effluent discharge leachatefrom a nearby dumpsite and stormwater from the nearbyharbour where shipping activities are ongoing among otherpossible sources However the maximum value recordedin the water samples was 141 indicating a relatively lowpetroleum contamination in the water column Degradedpetroleum residues may stay bound to soilssediments foryears and may bring about a short-term damage to aquaticlives and also impact the recreational use of the water bodynegatively [5]

345 Carbon Preference Index (CPI) This is an indicator fordominance of natural hydrocarbons over the anthropogenicones It reveals the ratio of odd to even carbon number n-alkanes from different categories Terrestrial vascular plantssourced hydrocarbons are identified with CPI values in therange of 3 to 10 while lower value close to 1 indicatespetroleum and anthropogenic activities such as combustionof fossil fuel effluent discharge and agricultural and woodrubbles mostly from industrial and urban areas [9 28 84]

CPI25ndash33 = 05 lowast [(C25ndashC33)(C

24ndashC32)] + [(C25ndashC33)

(C26ndashC34)] (1)

Table 5 shows CPI values obtained from this study inthe range of 1 and 3 increasing towards the ocean Thisshows that anthropogenic input decreases as marine inputincreases Generally the results indicate that Buffalo RiverEstuary is dominated by n-alkanes from both natural andanthropogenic origins [9 84]

346 C31C19 This is another important ratio used todifferentiate the sources of n-alkanes in water The presenceof nC31 is an indication of terrestrial biogenic hydrocarbonswhereas nC19 suggests marine biogenic inputs The C31C19ratio is therefore used to assess the dominance of n-alkanesfrom either of the two sources While ratio below 04 revealsmarines sources any value above 04 is an indication ofland derived or nonmarine hydrocarbons [28 78] Althoughwater samples from site E1 had no nC31 other samplinglocations gave higher values than 04 (Tables 3 and 4) whichare indicative of hydrocarbons mainly from anthropogenicorigins

347 Average Carbon Length (ACL) Average carbon lengthis an index used in the evaluation of odd carbon dominanceper molecule in environmental samples to establish the linkwith higher plants normal alkanes The value is usuallyconstant in nonpolluted sites but fluctuates with depletedvalues in the areas polluted with petroleum hydrocarbons[85] The values were calculated using the formula below aspreviously demonstrated [86 87]

ACL value

= 25 (nC25) + 27 (nC27) + 29 (nC29) + 31 (nC31) + 33 (nC33)C25+ C27+ C29+ C31+ C33

(2)

ACL in the Buffalo River Estuary sediments ranged between2738 and 3069 (Table 5) This shows about 331 units ofchanges The little deviations from the mean value werenoticed in January February and May Three of the fourstations were involved in the fluctuations except E1 that hadconstant value close to the mean all throughThe lowest ratiowas obtained inMay at E2 (2738) and the highest in Februaryat E4 (3069) The slight fluctuations observed across thesampling stations indicate a little anthropogenic contributionto the abundance of hydrocarbons and corroborate previousreports elsewhere [9 86] The results show a positive signif-icant correlation with CPI (119903 = 0699 119901 lt 001) thoughwith a lower regression (1198772 = 03535) (Figure 7) indicating arise in ACL as CPI increases [29] This relationship confirmsthat hydrocarbons in the Buffalo River Estuary are from bothnatural and anthropogenic origins because the CPI valueswere between 1 and 3 [78]

4 Conclusion

Physicochemical parameters of the Buffalo River Estuarywater were assessed in this study Almost all were foundwithin the acceptable threshold limits except pH turbidityand total suspended solids that slightly exceeded especiallyin May when the water was disturbed with a fresh and


ACLLinear (ACL)

05 1 15 2 25 3 350CPI

285

286

287

288

289

29

291

292

293

294

295

ACL

R2 = 03535

y = 03857x + 2808

Figure 7 Plot of ACL versus CPI in the sediment compartment ofBuffalo River Estuary

continual discharge of effluent at E3 Low dissolved oxygenconcentration was equally observed in summer (February)at E2 In the same vein the TPH concentrations in theestuary water and sediments ranged from 765 to 477120583gLand 1259 to 1100mgkg respectively Highest concentrationswere observed principally at E1 (Buffalo River inflow) and E3(second creek) and this possibly may be due to the industrialeffluent discharge leachate from a dumpsite close by andurbanagricultural runoffs Generally the observed TPHconcentration range signifies moderate to heavy pollutionlevels in the estuarine sediments

To the best of our knowledge this work on the petroleumhydrocarbon fingerprints of water and sediment in theestuary first of its kind within the Buffalo City MetropolitanMunicipality has been able to provide baseline data on thecurrent status of the estuary water Diagnostic ratios usedas biomarkers revealed that hydrocarbons in the area werefrom both natural and anthropogenic sources Proper andcontinuous monitoring of the quality parameters shouldtherefore be carried out so as to allow for effective pollutioncontrol in the aquatic environment

Conflicts of Interest

The authors declare that there are no conflicts of interest

Acknowledgments

The authors express their profound gratitude to the SouthAfrican Medical Research Council (SAMRC) and WaterResearch Commission (WRC) that funded this work Specialthanks are due to the National Research Foundation (NRF)for the student bursary and the ZoologyDepartment Univer-sity of Fort Hare for the assistance rendered in the sedimentcollection

References

[1] A Charriau L Bodineau B Ouddane and J-C FischerldquoPolycyclic aromatic hydrocarbons and n-alkanes in sedimentsof the Upper Scheldt River Basin contamination levels andsource apportionmentrdquo Journal of Environmental Monitoringvol 11 no 5 pp 1086ndash1093 2009

[2] V Tornero and M R drsquoAlcala ldquoContamination by hazardoussubstances in the Gulf of Naples and nearby coastal areas areview of sources environmental levels and potential impactsin theMSFD perspectiverdquo Science of the Total Environment vol466-467 pp 820ndash840 2014

[3] M J Kachel Particularly Sensitive Sea Areas The IMOrsquos Rolein Protecting Vulnerable Marine Areas Springer New York NYUSA 2008

[4] A Muthukumar G Idayachandiran S Kumaresan T AKumar and T Balasubramanian ldquoPetroleum hydrocarbons(PHC) in sediments of three different ecosystems from South-east Coast of Indiardquo nternational Journal of Pharmaceutical ampBiological Archives vol 4 no 3 pp 543ndash549 2013

[5] Agency for Toxic Substances and Disease Registry (ATSDR)Toxicological Profile for Total Petroleum Hydrocarbons (TPH)US Department of Health and Human Services Public HealthService Washington Wash USA 1999

[6] S Filho P J Luz G R Betemps M D R G Silva and EB Caramao ldquoStudies of n-alkanes in the sediments of colonyZ3 (Pelotas-RS-Brazil) Brazilian Journal of Aquatic Scienceand Technologyrdquo Brazilian Journal of Aquatic Science andTechnology vol 17 no 1 pp 27ndash33 2013

[7] Y Wu J Zhang T-Z Mi and B Li ldquoOccurrence of n-alkanesand polycyclic aromatic hydrocarbons in the core sediments ofthe Yellow SeardquoMarine Chemistry vol 76 no 1-2 pp 1ndash15 2001

[8] M G Commendatore and J L Esteves ldquoNatural and anthro-pogenic hydrocarbons in sediments from the Chubut River(Patagonia Argentina)rdquo Marine Pollution Bulletin vol 48 no9-10 pp 910ndash918 2004

[9] M Sakari L S Ting L Y Houng et al ldquoUrban effluent dis-charge into rivers a forensic chemistry approach to evaluate theenvironmental deteriorationrdquo World Applied Sciences Journalvol 20 no 9 pp 1227ndash1235 2012

[10] A Sharma R C Sharma and A Anthwal ldquoMonitoring phyto-plankton diversity in the hill stream Chandrabhaga of GarhwalHimalayasrdquo Life Science Journal vol 4 no 1 pp 80ndash84 2007

[11] V N Chigor T Sibanda and A I Okoh ldquoVariations inthe physicochemical characteristics of the Buffalo River inthe Eastern Cape Province of South Africardquo EnvironmentalMonitoring and Assessment vol 185 no 10 pp 8733ndash8747 2013

[12] F Gebreyohannes A Gebrekidan A Hadera and S EstifanosldquoInvestigations of physico-chemical parameters and its pol-lution implications of Elala River Mekelle Tigray EthiopiardquoMomona Ethiopian Journal of Science vol 7 no 2 pp 240ndash2572015

[13] WHO Guidelines for Drinking Water Quality vol 1ndash3 WorldHealth Organization (WHO) Geneva Switzerland 2nd edi-tion 1996

[14] J E Cortes A Suspes S Roa C Gonzalez and H E CastroldquoTotal petroleum hydrocarbons by gas chromatography inColombian waters and soilsrdquo American Journal of Environmen-tal Sciences vol 8 no 4 pp 396ndash402 2012

[15] B Z Hafiz A K Pandit and J A Shah ldquoPhytoplanktoncommunity of river Jehlum in Kashmir Himalayardquo Journal of


Environmental Science and Technology vol 7 no 6 pp 326ndash3362014

[16] R C Sharma N Singh and A Chauhan ldquoThe influence ofphysico-chemical parameters on phytoplankton distributionin a head water stream of Garhwal Himalayas a case studyrdquoEgyptian Journal of Aquatic Research vol 42 no 1 pp 11ndash212016

[17] P U Singare M P Trivedi and R M Mishra ldquoAssessing thephysico-chemical parameters of sediment ecosystem of VasaiCreek at Mumbai Indiardquo Marine Science vol 1 no 1 pp 22ndash29 2011

[18] M C Onojake and L C Osuji ldquoAssessment of the physico-chemical properties of hydrocarbon contaminated soilrdquoArchives of Applied Science Research vol 4 no 1 pp 48ndash582012

[19] River Health Programme (RHP) ldquoState of rivers report Buffaloriver systemrdquo Tech Rep Department of Water Affairs andForestry Pretoria South Africa 2004

[20] EOHCES ldquoBuffalo River Estuaryrdquo Draft Situation AssessmentReport EOH Coastal amp Environmental Services East LondonSouth Africa 2016

[21] A A Olajire A O Alade A A Adeniyi andOM OlabemiwoldquoDistribution of polycyclic aromatic hydrocarbons in surfacesoils and water from the vicinity of Agbabu bitumen field ofSouthwestern Nigeriardquo Journal of Environmental Science andHealthmdashPart A ToxicHazardous Substances and EnvironmentalEngineering vol 42 no 8 pp 1043ndash1049 2007

[22] G H M Tehrani H Rosli A H Sulaiman et al ldquoPetroleumhydrocarbon assessment in the wastewaters of petrochemicalspecial economic zone and sediment benchmark calculation ofthe coastal area-northwest of the Persian Gulfrdquo Iranian Journalof Fisheries Sciences vol 13 no 1 pp 119ndash134 2014

[23] S Suratman ldquoDistribution of total petrogenic hydrocarbon inDungun River basin Malaysiardquo Oriental Journal of Chemistryvol 29 no 1 pp 77ndash80 2013

[24] N Gupta K K Yadav V Kumar and D Singh ldquoAssessmentof physicochemical properties of Yamuna River in Agra CityrdquoInternational Journal of Chemical and Technological Researchvol 5 no 1 pp 528ndash531 2013

[25] Washington State Department of Ecology (WSDE) AnalyticalMethods for Petroleum Hydrocarbons Department of EcologyPublications Distribution Center Olympia Wash USA 1997

[26] M R Motsara and R N Roy ldquoGuide to laboratory estab-lishment for plant nutrient analysisrdquo FAO Fertilizer and PlantNutrition Bulletin vol 19 pp 38ndash42 2008

[27] I A Al-Baldawi S R S Abdullah N Anuar F Suja and IMushrifah ldquoPhytodegradation of total petroleum hydrocarbon(TPH) in diesel-contaminated water using Scirpus grossusrdquoEcological Engineering vol 74 pp 463ndash473 2015

[28] O E Ahmed S A Mahmoud and A E M Mousa ldquoAliphaticand poly-aromatic hydrocarbons pollution at the drainage basinof Suez Oil Refinery Companyrdquo Current Science Internationalvol 4 no 1 pp 27ndash44 2015

[29] M Sakari M P Zakaria M Junos et al ldquoSpatial distribution ofpetroleum hydrocarbon in sediments of major rivers from eastcoast of Peninsular Malaysiardquo Coastal Marine Science vol 32pp 1ndash10 2008

[30] T F da Silva D de Almeida Azevedo and F R de Aquino NetoldquoDistribution of polycyclic aromatic hydrocarbons in surfacesediments and waters from Guanabara Bay Rio de JaneiroBrazilrdquo Journal of the Brazilian Chemical Society vol 18 no 3pp 628ndash637 2007

[31] O L G Maioli K C Rodrigues B A Knoppers and D AAzevedo ldquoDistribution and sources of aliphatic and polycyclicaromatic hydrocarbons in suspended particulate matter inwater from two Brazilian estuarine systemsrdquo Continental ShelfResearch vol 31 no 10 pp 1116ndash1127 2011

[32] W Luan and M Szelewski ldquoUltra-fast total petroleum hydro-carbons (TPH) analysis with Agilent low thermal mass (LTM)GC and simultaneous dual-tower injectionrdquo Agilent Technolo-gies Application Note Environmental pp 1ndash8 2008

[33] A Caruso and M Santoro Detection of Organochlorine Pes-ticides by GC-ECD following US EPA Method 8081 ThermoFisher Scientific Milan Italy 2014

[34] T J Nekhavhambe T van Ree andO S Fatoki ldquoDeterminationand distribution of polycyclic aromatic hydrocarbons in riverssurface runoff and sediments in and around ThohoyandouLimpopo Province South Africardquo Water SA vol 40 no 3 pp415ndash424 2014

[35] G Schwarz S Baumler A Block F G Felsenstein and GWenzel ldquoDetermination of detection and quantification limitsfor SNP allele frequency estimation in DNA pools using realtime PCRrdquo Nucleic Acids Research vol 32 no 3 article e242004

[36] United Nations Environment Programme Global EnvironmentMonitoring System (UNEPGEMS)Water Programme WaterQuality for Ecosystem And Human Health 2nd edition 2008

[37] Department of Environmental Affairs (DEA) ldquoChapter 9Oceans and Coasts Ocean and coasts ecosystem servicesare important as they directly and indirectly impact onhuman livelihoods food security and agriculture trade andindustryrdquo South Africa Environment Outlook Draft 2 1722012 httpwebcachegoogleusercontentcomsearchq=cache4tKKksh1AFQJsoerdeatgovzaDEA_-_Main_doc_-_Chapter_9_px-PSpdffile+ampcd=1amphl=tnampct=clnkampgl=za

[38] J A Sciortino and R Ravikumar Fishery Harbour Manual onThe Prevention of Pollution Hay of Bengal ProgrammeMadrasIndia 1990

[39] J F N Abowei ldquoSalinity dissolved oxygen pH and surfacewater temperature conditions in Nkoro River Niger DeltaNigeriardquo Advance Journal of Food Science and Technology vol2 no 1 pp 36ndash40 2010

[40] Fondriest Environmental (FEI) ldquoConductivity salinity andtotal dissolved solids fundamentals of environmental mea-surementsrdquo 2014 httpwwwfondriestcomenvironmental-measurementsparameterswater-qualityconductivity-salinity-tds

[41] O S Fatoki P Gogwana and A O Ogunfowokan ldquoPollutionassessment in the Keiskamma River and in the impoundmentdownstreamrdquoWater SA vol 29 no 2 pp 183ndash187 2003

[42] T N Kildea and L Andreacchio Adelaide Desalination ProjectSalinity ph and Dissolved Oxygen Water Quality Data MarineExclusion Zone Australian Water Quality Centre AdelaideAustralia 2012 The Clean Water Team Guidance Com-pendium for Watershed Monitoring and Assessment StateWater Resources Control Board

[43] DNREAS Objectives for The Darwin Harbour RegionmdashBack-ground Document Department of Natural Resources Environ-ment Arts and Sport (DNREAS) 2010

[44] Fondriest Environmental (FEI) ldquoDissolved oxygen funda-mentals of environmental measurementsrdquo 2013 httpwwwfondriestcomenvironmental-measurementsparameterswa-ter-qualitydissolved-oxygen


[45] CCME CanadianWater Quality Guidelines for the Protection ofAquatic Life Polycyclic Aromatic Hydrocarbons (PAHs) Cana-dian Council of Ministers of the Environment (CCME) 1999

[46] A Whitfield and G Bate ldquoA review of information on tem-porarily openclosed estuaries in the warm and cool temperatebiogeographic regions of SouthAfrica with particular emphasison the influence of River Flow on these systemsrdquo WRC Report1581107 iii-vii 2007

[47] J Dunlop G McGregor and N Horrigan Potential impacts ofsalinity and turbidity in riverine ecosystems Characterisationof impacts and a discussion of regional target setting for riverineecosystems in Queensland Queensland Department of NaturalResources and Water Queensland Australia 2005

[48] RMirza I Faghiri and E Abedi ldquoContamination of polycyclicaromatic hydrocarbons in surface sediments of Khure-MusaEstuarine Persian Gulfrdquo World Journal of Fish and MarineSciences vol 4 no 2 pp 136ndash141 2012

[49] KDHE ldquoKansas method for the determination of mid-rangehydrocarbons (MRH) and high-range hydrocarbons (HRH)Revision 10rdquo Tech Rep Kansas Department of Health andEnvironment (KDHE) 2015

[50] M S Massoud F Al-Abdali A N Al-Ghadban and M Al-Sarawi ldquoBottom sediments of the Arabian Gulf-II TPH andTOC contents as indicators of oil pollution and implicationsfor the effect and fate of the Kuwait oil slickrdquo EnvironmentalPollution vol 93 no 3 pp 271ndash284 1996

[51] A AMaktoof B Y ALKhafaji and Z Z Al-janabi ldquoEvaluationof total hydrocarbons levels and traces metals in water and sed-iment from main Outfall Drain in Al-Nassiriya CitySouthernIraqrdquo Natural Resources vol 5 no 13 pp 795ndash803 2014

[52] M Kim S H Hong J Won et al ldquoPetroleum hydrocarboncontaminations in the intertidal seawater after the Hebei Spiritoil spill e Effect of tidal cycle on the TPH concentrations and thechromatographic characterization of seawater extractsrdquo WaterResearch vol 47 pp 758ndash768 2013

[53] C A Brebbia Water Resources Management VII WIT PressSouthampton UK

[54] Y Li Y Zhao S Peng Q Zhou and L Q Ma ldquoTemporal andspatial trends of total petroleum hydrocarbons in the seawaterof Bohai Bay China from 1996 to 2005rdquo Marine PollutionBulletin vol 60 pp 238ndash243 2010

[55] A R Abdullah W C Woon and R A Bakar ldquoDistributionof oil and grease and petroleum hydrocarbons in the Straits ofJohor Peninsular Malaysiardquo Bulletin of Environmental Contam-ination and Toxicology vol 57 no 1 pp 155ndash162 1996

[56] C M Reddy and J G Quinn ldquoGC-MS analysis of totalpetroleumhydrocarbons and polycyclic aromatic hydrocarbonsin seawater samples after the North Cape oil spillrdquo MarinePollution Bulletin vol 38 no 2 pp 126ndash135 1999

[57] I J Alinnor and M A Nwachukwu ldquoDetermination of totalpetroleum hydrocarbon in soil and groundwater samples insome communities in Rivers State Nigeriardquo Journal of Environ-mental Chemistry and Ecotoxicology vol 5 no 11 pp 292ndash2972013

[58] G O Adewuyi O T Etchie and O T Ademoyegun ldquoDeter-mination of total petroleum hydrocarbons and heavy metalsin surface water and sediment of Ubeji River Warri NigeriardquoBioremediation Biodiversity and Bioavailability vol 5 no 1 pp46ndash51 2011

[59] G O Adewuyi and R A Olowu ldquoAssessment of oil and greasetotal petroleumhydrocarbons and someheavymetals in surface

and groundwater within the vicinity of NNPC Oil Depot inApata Ibadan Metropolis Nigeriardquo International Journal ofResearch and Revies in Applied Sciences vol 13 no 1 pp 166ndash174 2012

[60] S Suratman N M Tahir and M T Latif ldquoA Preliminarystudy of total petrogenic hydrocarbon distribution in SetiuWetland Southerzn South China Sea (Malaysia)rdquo Bulletin ofEnvironmental Contamination and Toxicology vol 88 no 5 pp755ndash758 2012

[61] P V Shirodkar M Deepthi P Vethamony et al ldquoTidedependent seasonal changes in water quality and assimilativecapacityof anthropogenically influenced Mormugao harbourwaterrdquo Indian Journal of Geo-Marine Sciences vol 41 no 4 pp314ndash330 2012

[62] DPR ldquoEGASPIN soilsediment target and intervention valuesfor Mineral oil (or TPH)rdquo in Environmental Guidelines andStandards forThe Petroleum Industry inNigeria vol 2 pp 1ndash415Department of Petroleum Resources (DPR) Lagos Nigeria2002

[63] UNEP ldquoOkenogban-Alode UNEP environmental assessmentof Ogoniland siterdquo in Specific Fact Sheets pp 1ndash11 UnitedNations Environment Programme (UNEP) 2011

[64] G M M Tehrani R Hshim S H Halim S B T Sany R KJazani and Z M Tehrani ldquoAssessment of contamination bypetroleum hydrocarbons in sediments of Musa Bay Northwestof the Persian Gulf-Iranrdquo International Proceedings of ChemicalBiological and Environmental Engineering vol 33 pp 75ndash802012

[65] J M Guerra-Garcıa and J C Garcıa-Gomez ldquoAssessing pol-lution levels in sediments of a harbor with two opposingentrances Environmental implicationsrdquo Journal of Environ-mental Management vol 77 no 1 pp 1ndash11 2005

[66] M S Massoud F Al-Abdali and A N Al-Ghadban ldquoThestatus of oil pollution in the Arabian Gulf by the end of 1993rdquoEnvironment International vol 24 no 1-2 pp 11ndash22 1998

[67] R Zhou X Qin S Peng and S Deng ldquoTotal petroleumhydrocarbons and heavy metals in the surface sediments ofBohai Bay China long-term variations in pollution status andadverse biological riskrdquoMarine Pollution Bulletin vol 83 no 1pp 290ndash297 2014

[68] G M Tehrani R Hashim A H Sulaiman et al ldquoDistribu-tion of total petroleum hydrocarbons and polycyclic aromatichydrocarbons in musa bay sediments (Northwest of the PersianGulf)rdquo Environment Protection Engineering vol 39 no 1 pp115ndash128 2013

[69] S AMohdAli R Tair S Z Yang andMMohdAli ldquoPetroleumhydrocarbon in surface sediment from coastal area of Putatanand Papar SabahrdquoMalaysian Journal of Analytical Sciences vol17 no 2 pp 286ndash290 2013

[70] S L Mohebbi-Nozar M P Zakaria W R Ismail et al ldquoTotalpetroleum hydrocarbons in sediments from the coastline andmangroves of the northern Persian Gulfrdquo Marine PollutionBulletin vol 95 no 1 pp 407ndash411 2015

[71] EPA Victoria ldquoWater quality objectives for rivers andstreamsmdashecosystem protectionrdquo Information Bulletin vol791 no 1 pp 8ndash12 2003

[72] M Trapido ldquoPolycyclic aromatic hydrocarbons in Estonian soilcontamination and profilesrdquo Environmental Pollution vol 105no 1 pp 67ndash74 1999

[73] MAGorleku D Carboo LMN PalmW J Quasie andA KArmah ldquoPolycyclic aromatic hydrocarbons (PAHs) pollution in


marine waters and sediments at the Tema Harbourrdquo AcademiaJournal of Environmental Sciences vol 2 no 7 pp 108ndash115 2014

[74] M A Gouch M M Rhead and S J Rowland ldquoBiodegrada-tion studies of unresolved complex mixtures of hydrocarbonsmodel UCM hydrocarbons and the aliphatic UCMrdquo OrganicGeochemistry vol 18 no 1 pp 17ndash22 1992

[75] F Duan Fengkui K He and X Liu ldquoCharacteristics and sourceidentification of fine particulate n-alkanes in Beijing ChinardquoJournal of Environmental Sciences vol 22 no 7 pp 998ndash10052010

[76] X Gao and S Chen ldquoPetroleum pollution in surface sedimentsof Daya Bay South China revealed by chemical fingerprintingof aliphatic and alicyclic hydrocarbonsrdquo Estuarine Coastal andShelf Science vol 80 no 1 pp 95ndash102 2008

[77] R R Harji A Yvenat and N B Bhosle ldquoSources of hydrocar-bons in sediments of the Mandovi estuary and the Marmugoaharbour west coast of IndiardquoEnvironment International vol 34no 7 pp 959ndash965 2008

[78] O E Fagbote and E O Olanipekun ldquoCharacterization andsources of aliphatic hydrocarbons of the sediments of RiverOluwa at Agbabu Bitumen deposit area Western NigeriardquoJournal of Scientific Research and Reports vol 2 no 1 pp 228ndash248 2013

[79] M P Zakaria H Takada S Tsutsumi et al ldquoDistribution ofpolycyclic aromatic hydrocarbons (PAHs) in rivers and estuar-ies in Malaysia widespread input of petrogenic hydrocarbonsrdquoEnvironmental Science and Technology vol 36 no 9 pp 1907ndash1918 2002

[80] X-C Wang S Sun H-Q Ma and Y Liu ldquoSources anddistribution of aliphatic and polyaromatic hydrocarbons insediments of Jiaozhou Bay Qingdao Chinardquo Marine PollutionBulletin vol 52 no 2 pp 129ndash138 2006

[81] T S Bianchi Biogeochemistry of Estuaries Oxford UniversityPress Chicago Ill USA 6th edition 2007

[82] A J Turki ldquoDistribution and Sources of Aliphatic Hydrocar-bons in Surface Sediments ofAl-Arbaeen Lagoon Jeddah SaudiArabiardquo Journal of Fisheries amp Livestock Production vol 4 no2 pp 1ndash10 2016

[83] M C Kennicutt II G Denoux A Klein et al ldquoTemporaland spatial patterns of anthropogenic disturbance at McMurdoStation Antarcticardquo Environmental Research Letters vol 5 no3 2010

[84] M A de Abreu-Mota C A de Moura Barboza M CBıcego and C C Martins ldquoSedimentary biomarkers along acontamination gradient in a human-impacted sub-estuary inSouthern Brazil a multi-parameter approach based on spatialand seasonal variabilityrdquo Chemosphere vol 103 pp 156ndash1632014

[85] W-L Jeng ldquoHigher plant n-alkane average chain length as anindicator of petrogenic hydrocarbon contamination in marinesedimentsrdquo Marine Chemistry vol 102 no 3-4 pp 242ndash2512006

[86] R Kiran V V J G Krishna B GNaik et al ldquoCan hydrocarbonsin coastal sediments be related to terrestrial flux A case studyof Godavari river discharge (Bay of Bengal)rdquo Current Sciencevol 108 no 1 pp 96ndash100 2015

[87] M Wang W Zhang and J Hou ldquoIs average chain length ofplant lipids a potential proxy for vegetation environment andclimate changesrdquoBiogeosciences Discuss vol 12 pp 5477ndash55012015

Submit your manuscripts athttpswwwhindawicom

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CatalystsJournal of


oxygen temperature turbidity conductivity total dissolvedsolids and total suspended solids [11 15 16] Analysis of sed-iments qualities has also been found very paramount beinga major site for organic matter decomposition Continuousaccumulation of pollutants due to biological and geochemicalmechanisms can be toxic to the sediment dwelling organismsand fish resulting in decreased survival reduced growth orimpaired reproduction and lowered species diversity Somerecent findings on quality parameters of sediment like pHelectrical conductivity moisture content organic carbon andorganic matter were also reported [17 18]

Buffalo River Estuary is the mouth part of the longBuffalo River that covers about 1287 km2 area before draininginto the Indian Ocean in the coastal city of East LondonThe river flows through some major towns (Bhisho KingWilliamrsquos Town Zwelitsha Mdantsane and East London)and industrial areas that cover almost 12 of its catchmentarea Three major tributaries that feed the Buffalo River withrunoffs raw sewage solid wastes and industrial effluentsare the Mgqakwebe Ngqokweni and Yellowwoods riversmainly from densely populated urban and agricultural areasof the province [19] Surrounding the estuary are the EastLondon harbour and other direct users like Sea Spirit FishMarket Vukani Petroleum BP South Africa Mercedes BenzSouth Africa Chevron (Pty) Ltd Engen and Total SouthAfrica among others First and SecondCreeks are instances ofinfluent rivers which contribute to the inflow of stormwatersewerage and domestic and industrial runoffs into theestuary [20]

Previous environmental studies in the area focused onthe physicochemical characteristics and microbial and heavymetal contamination of the environmental matrices [19]However no report is available yet on the petroleum hydro-carbonprofiles in both thewater and sediment compartmentsof the estuary which is the subject of this current study In thispaper we report on the petroleum hydrocarbon fingerprintsof water and bottom sediments of the Buffalo River Estuaryin the Eastern Cape Province South Africa

2 Materials and Method

21 Description of Study Area The Buffalo River Estuary(33∘021015840S 27∘551015840E) is the largest and one of themost importantriver estuaries in the Eastern Cape Province of South Africaand located in the Buffalo City Metropolitan MunicipalityEast London [19] It receives stormwater from the shippingactivities at the East London harbour industrial effluentsdomestic wastes urban runoff and vehicular emissions fromSteve Biko and Buffalo Bridges either directly or indirectlythrough its influent rivers

22 Cleaning of Glass Bottles and Sample Collection Amberglass bottles used for sample collection were washed with tapwater and detergent and rinsed with distilled water followedby acetone Calibration standards high performance liq-uid chromatographic (HPLC) grade solvents and analyticalgrade reagents used for this work were sourced from Merck(Germany) and Restek and Accustandard (USA)

Figure 1 Map of Buffalo River Estuary East London

Five (5) sampling locations on the Buffalo River Estuarywere chosen on the basis of the level of anthropogenic pres-sures (Table 1 Figure 1) Monthly sampling was undertakenbetween January and May 2016 mostly during the high tideexcept in February spanning through summer and autumnseasons Duplicate water samples were collected 100mmbelow the surface level from two points (about 5m apart)in each sampling location with precleaned 1 L amber bottlespooled together to obtain a representative sample [21] Theywere acidified to pH lt 2 using 6M hydrochloric acid (HCl)The sediment samples were however collected only from 4locations using Van Veen Grab sampler because the estuarysubstratum at E5 was rocky All the samples were transportedto the laboratory immediately on ice chest for analysis [2223]

23 Physicochemical Analyses of the Samples TemperaturepH electrical conductivity (EC) and total dissolved solids(TDS) of the aqueous samples were determined on-site usingHanna multiparameter probe (HI 98195) while turbiditydissolved oxygen and total suspended solids (TSS)weremea-sured using Hach instruments (Hach Company USA) [24]Sediment samples were analyzed for moisture organic car-bon and organic matter contents using gravimetric method[25 26]

24 Extraction of Petroleum Hydrocarbon from Surface Waterand Sediment Samples Exactly 500mL of water sample wasspiked with 1mL of 10 120583gmL 1-chlorooctadecane (COD)used as surrogate standard extracted thrice in a separatingfunnel with 20mL of n-hexane each time The extractswere pooled together dried with anhydrous sodium sul-phate (20 g) and concentrated to about 2mL using rotaryevaporator ready for column cleanup [25 27 28] Sedimentsamples were air-dried for 5 days Also 10 g aliquot of the air-dried sediment sample was blended with sufficient quantityof anhydrous sodium sulphate (Na

2SO4) to removemoisture

spiked with 1mL of 10 120583gmLCOD and extracted in a Soxhletextractor with 200mL of dichloromethane for 24 h Theextract was allowed to pass through a glass funnel containinganhydrous sodium sulphate and reduced to approximately2mL using rotary evaporator It was then solvent exchangedto n-hexane before the cleanup stage [25 29]







E3 330261∘S 278830∘E 444


E4 330243∘S 278907∘E 616


































Series 1

020406080

100120140160180

Mea

n co

ncen

trat

ions

(휇g

L)






Series 1

0

50000

100000

150000

200000

250000

300000

350000

400000

450000

Mea

n co

ncen

trat

ions

(휇g

kg)




















TOCLinear (TOC)

R2 = 01043

y = 00184x + 57095

0

10000

20000

30000

40000

50000

60000

70000

80000TO

C (휇

gkg

)

10000000 20000000 30000000 40000000000TPH (휇gkg)













255075

100125150175200225

(pA

)

10 15 20 25 30 355(min)



20406080

100

(pA

)

10 15 20 25 30 355(min)







(C26ndashC34)] (1)




ACL value


(2)


4 Conclusion



ACLLinear (ACL)

05 1 15 2 25 3 350CPI

285

286

287

288

289

29

291

292

293

294

295

ACL

R2 = 03535

y = 03857x + 2808






Acknowledgments


References







































































































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of







E3 330261∘S 278830∘E 444


E4 330243∘S 278907∘E 616


































Series 1

020406080

100120140160180

Mea

n co

ncen

trat

ions

(휇g

L)






Series 1

0

50000

100000

150000

200000

250000

300000

350000

400000

450000

Mea

n co

ncen

trat

ions

(휇g

kg)




















TOCLinear (TOC)

R2 = 01043

y = 00184x + 57095

0

10000

20000

30000

40000

50000

60000

70000

80000TO

C (휇

gkg

)

10000000 20000000 30000000 40000000000TPH (휇gkg)













255075

100125150175200225

(pA

)

10 15 20 25 30 355(min)



20406080

100

(pA

)

10 15 20 25 30 355(min)







(C26ndashC34)] (1)




ACL value


(2)


4 Conclusion



ACLLinear (ACL)

05 1 15 2 25 3 350CPI

285

286

287

288

289

29

291

292

293

294

295

ACL

R2 = 03535

y = 03857x + 2808






Acknowledgments


References







































































































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of
























Series 1

020406080

100120140160180

Mea

n co

ncen

trat

ions

(휇g

L)






Series 1

0

50000

100000

150000

200000

250000

300000

350000

400000

450000

Mea

n co

ncen

trat

ions

(휇g

kg)




















TOCLinear (TOC)

R2 = 01043

y = 00184x + 57095

0

10000

20000

30000

40000

50000

60000

70000

80000TO

C (휇

gkg

)

10000000 20000000 30000000 40000000000TPH (휇gkg)













255075

100125150175200225

(pA

)

10 15 20 25 30 355(min)



20406080

100

(pA

)

10 15 20 25 30 355(min)







(C26ndashC34)] (1)




ACL value


(2)


4 Conclusion



ACLLinear (ACL)

05 1 15 2 25 3 350CPI

285

286

287

288

289

29

291

292

293

294

295

ACL

R2 = 03535

y = 03857x + 2808






Acknowledgments


References







































































































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of















TOCLinear (TOC)

R2 = 01043

y = 00184x + 57095

0

10000

20000

30000

40000

50000

60000

70000

80000TO

C (휇

gkg

)

10000000 20000000 30000000 40000000000TPH (휇gkg)













255075

100125150175200225

(pA

)

10 15 20 25 30 355(min)



20406080

100

(pA

)

10 15 20 25 30 355(min)







(C26ndashC34)] (1)




ACL value


(2)


4 Conclusion



ACLLinear (ACL)

05 1 15 2 25 3 350CPI

285

286

287

288

289

29

291

292

293

294

295

ACL

R2 = 03535

y = 03857x + 2808






Acknowledgments


References







































































































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of



255075

100125150175200225

(pA

)

10 15 20 25 30 355(min)



20406080

100

(pA

)

10 15 20 25 30 355(min)







(C26ndashC34)] (1)




ACL value


(2)


4 Conclusion



ACLLinear (ACL)

05 1 15 2 25 3 350CPI

285

286

287

288

289

29

291

292

293

294

295

ACL

R2 = 03535

y = 03857x + 2808






Acknowledgments


References







































































































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of


ACLLinear (ACL)

05 1 15 2 25 3 350CPI

285

286

287

288

289

29

291

292

293

294

295

ACL

R2 = 03535

y = 03857x + 2808






Acknowledgments


References







































































































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of
























































































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of

petroleum hydrocarbon fingerprints of water and sediment...

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