chapter –...

SubhashChand,Seema,RekhaRani,Vijayata

CHAPTER – V


CONCLUSIONS &

SUGGESTIONS

The Present work is basically of applied nature. The whole work

is related to the development of new inorganic materials and their

characterization on the basis of certain parameters which ultimately

become helpful in deciding the application of the synthesized materials


for separation purposes. These separations show their significance in

water pollution control by ion exchange. These developed materials

are of specific type of ion-exchangers known as inorganic cation

exchangers. These exchangers are solid materials which are

responsible for a phenomenon known as ion exchange. In least words

almost work is based on a separation technique known as ion-

exchange.

It has been known for a long time that certain minerals can

exchange one ion for another :

R-A+B+ R-B+A+

These developed materials are of specific type of ion

exchangers known as inorganic action exchangers. Though a number

of inorganic cation exchangers have been reported yet there is the

need of more and more and better and better inorganic cation

exchangers. From type of ion-exchangers point of view I would say

that my focus is on inorganic cation exchangers only. In this

connection it isimportant to mention that my exchangers are based on

antimony(IV) and bismuth(III) metal ions. If I state the class of my ion

exchangers on the basis of number of components present in them I can say

that my cation exchangers are three component inorganic cation ion

exchangers. My aim was to develop better exchangers at least from some of

reported ion-exchangers in different ways. On comparing with the reported

exchangers, I am happy to state that my exchangers were found to be better


in one way or the other from some of the reported cation exchangers.

Initially at the time of the submission of my synopsis to C.C.S. University for

the approval of my proposed research plan, infrastructure available at the

place of work, economic aspect and availability of the chemicals and other

required materials in the market were kept in view. After my research work

now I can conclude that all the considerations taken at the beginning proved

to be fruitful in making available the different things required in doing the

different experiments etc. Even after unavailability of any financial support

research work went on smoothly. Time was very important factor as the lab

was available to us from 9.00 am to 5.00 pm only. It was not possible to avail

the lab before and after the stated time. Therefore sometime it was

inconvenient to perform the lengthy experimental procedures. Anyway i

succeeded in synthesizing three new inorganic cation exchange

materials which may be called inorganic cation exchangers. These

exchangers were characterized on the basis of ion exchange capacity,

thermal stability, chemical stability distribution studies and instrumental

studies which included IR, TGA and XRD. Characterization of the

exchangers were done keeping in view the application. The

exchangers were applied for binary separation of metal ion pairs and

removal of metal ions from aqueous media.

First synthesized inorganic cation exchanger is antimony(III)

iodovanadate which was prepared by the mixing of the solutions of

antimony trichloride, potassium iodotate and sodium metavanadate in

3:2:2 ratio respectively. Ion exchange capacity was determined by


column method and I.E.C. was found to be 2.46 meq/g for Na+ ions.

The ion exchange capacity was also determined by PH titration

method. I.E.C. was found to be nearly same. In addition to sodium

ions I.E.C. for K+, Mg2+, Ca2+, and Ba2+ were also determined. The

results are recorded in table 2.4 of chapter II. Thermal stability of the

exchanger was studied in the laboratory using muffle furnace. Different

samples of the exchanger of the same amount were exposed

todifferent temperatures for same time. Loss in weight of each sample

was recorded. It was concluded that there is no loss in weight of the

exchanger up to 500C. At 1000C only 2% loss in the weight of the

exchanger was recorded. Even at 3500C only12% loss in weight was

determined. Heating effect on IEC of the exchanger was also seen. At

500C the exchanger is not found to loose its I.E.C. while at 1000C loss

in IEC was seen to be 0.12 meq/g. Chemical stability was studied against six solutions of different strengths. 2M H2SO4, 4M H2SO4, 4M

HNO3, 4M HCl, 2M NaOH and 2M NH4Cl were found to have effect on

the ion exchanger. Ion-exchanger was completely dissolved in 4M

HCl. Distribution studies were carried out for Mg2+, Zn2+, Cd2+, Pb2+,

Ni2+, Co2+, and Mn2+ using batch method. Kd values were calculated

using the following expression :

Kd =

Where

I = Initial amount of the ion in the solution phase.


F = Final amount of the ion in the solution phase.

V = Volume of the solution (ml).

W = Weight of the ion exchanger (g).

High Kd value was found for Ni2+ that is 111.25 ml/g

while Kd values for Mg2+, Zn2+, Cd2+, Pb2+ were found 90.5, 4.13,

18.4, and 16.44 respectively. Metal ion pairs Ni2+-Zn2+, Ni2+-Pb2+,

Pb2+-Zn2+ and Ni2+-Cd2+ were selected for Binary separation using

the exchanger on the basis of large difference in Kd values of the

metal ion pairs. In Pb2+-Zn2+ metal ion pair 100% elution was achieved

for Pb2+ ions. Toxic metal ions such Pb2+, Cd2+ and Ni2+were

successfully removed using different eluents and exchanger. Different

components of the exchanger were confirmed on the basis of IR.

Thermal stability was also interpreted with the help of TGA curve.

Crystalline nature of the exchanger was ascertained on the basis of

XRD of the exchanger.

Second synthesized inorganic cation exchanger is bismuth(III)

iodotungstate which was prepared by the mixing of the solutions of

bismuth nitrate, potassium iodate and sodium tungstate in 1:2:2 ratio

respectively. Ion exchange capacity was determined by column

method and was found to be 1.00 meq/g for Na+ ions. The ion

exchange capacity was also determined by PH titration method. IEC

was found to be nearly same. In addition to sodium ions I.E.C. for K+,

Mg2+, Ca2+, and Ba2+ were also determined. The results are recorded

in table 3.4 of chapter III. Thermal stabilityof the exchanger was


studied in the laboratory using muffle furnace. Different samples of the

exchanger of the same amount were exposed to different

temperatures for same time. Loss in weight of each sample was

recorded. It was concluded that there is no loss in weight of the


exchanger was recorded. Even at 3500C only 8% loss in weight was


500 C the exchanger is found to loose its IEC by 1% while at 1000C

loss in IEC was seen to be 19%. Chemical stability was studied against twenty five solutions of different strengths. 0.05 M H2SO4, 0.05

M HNO3 and 0.05 M HCl were found to have no effect on the ion

exchanger. 0.1M H2SO4, M H2SO4, 0.2 H2SO4, 2M H2SO4, 0.1M

HNO3, M HNO3 0.2M HNO3, 2M HNO3, 0.1M HCI, M HCI 0.2M HCI,

2M HCI, M KOH, 0.2M KOH, 0.1M NaOH, M NaOH, 0.2M NaOH, M NaNO3, 0.2M NaNO3 & 2M NaNO3 solutions on treating with ion-

exchanger dissolved the exchanger partially while the exchanger was

found to be completely dissolved in 2M KOH and 2M NaOH.

Distribution studies were carried out for Mg2+, Zn2+, Cd2+, Pb2+, Ni2+,

Co2+, and Mn2+ using batch method. Kd values were calculated

using the expression as stated earlier.

High Kd value was found for Ni2+ that is 111.25 ml/g

while Kd values for Mg2+, Zn2+, Cd2+, Pd2+ were found 5.85, 12.73,

3.39, and 4.74 respectively. Metal ion pairs Ni2+-Zn2+, Ni2+-Pb2+, Ni2+-

Mg2+ and Ni2+-Cd2+ were selected for binary separation using the


exchanger on the basis of large difference in Kd values of the metal

ion pairs. In Ni2+-Pb2+ and Ni2+-Cd2+ metal ion pairs 100% elution was

achieved for Ni2+ ions. Toxic metal ions such ions Pb2+, Cd2+ and

Ni2+were successfully removed using different eluents and exchanger.

Different components of the exchanger were confirmed on the basis of

IR. Thermal stability was also Interpreted with the help of TGA curve.

Amorphous nature of the exchanger was ascertained on the basis of

XRD of the exchanger.

Third synthesized inorganic cation exchanger is antimony(III)

tungstosilicate which was prepared by the mixing of the solutions of

antimony trichloride, potassium iodotate and sodium metavanadate in

3:2:2 ratio respectively. Ion exchange capacity was determined by

column method and I.E.C. was found to be 0.76 meq/g for Na+ ions.

The ion exchange capacity was also determined by PH titration

method. I.E.C. was found to be nearly same. In addition to sodium

ions I.E.C. for K+, mg2+, Ca2+, and Ba2+ werealso determined. The

results are recorded in table 4.4 of chapter IV. Thermal stability of the

exchanger was studied in the laboratory using muffle furnace. Different

samples of the exchanger of the same amount were exposed to

different temperatures for the same time. Loss in weight was recorded

of each sample. It was concluded that their is no loss in weight of the


exchanger was recorded. Even at 3500C only 10% loss in weight was



500 C the exchanger is found to loose its IEC by 8% while at 1000C

loss in I.E.C was seen to be 22%. Chemical stability was studied against six solutions of different strengths. 2M H2SO4, 4M H2SO4, 4M

HNO3, 4M HCl, 2M NaOH and 2M NH4Cl were found to have effect on

the ion exchanger. Ion-exchanger completely dissolved in 4M HCl.

Distribution studies were carried out for Mg2+, Zn2+, Cd2+, Pb2+, Ni2+,

Co2+, and Mn2+ using batch method. Kd values were calculated using

the earlier stated expression.

High Kd value was found for Ni2+ that is 120 ml/g while Kd

values for Mg2+, Zn2+, Pb2+ were found 85, 5 and 16.85 respectively.

Metal ion pairs Ni2+-Zn2+, Ni2+-Pb2+, Pb2+-Zn2+ and Pb2+-Mg2+ were

selected for Binary separationusing the exchanger on the basis of

large difference in Kd values of the metal ion pairs. In Ni2+-Pb2+ and

Ni2+-Cd2+ metal ion pairs 100% elution was ensured for Ni2+ ions. The

results are recorded in table 4.10 of Chapter IV.

Toxic metal ions such ions Pb2+, Cd2+ and Ni2+were

successfully removed using different eluents and exchanger. Different

components of the exchanger were confirmed on the basis of IR.

Thermal stability was also interpreted with the help of TGA curve.

Amorphous nature of the exchanger was ascertained on the basis of

XRD. Aforesaid ion exchangers were compared with some of the

reported ion exchangers such as zirconium(IV) tungstoiodophosphate,

zirconium(IV) tungstate, zirconium(IV) iodophosphate, zirconium(IV)


iodomolybdate, zirconium(IV) iodovanadate, tin(IV) tungstate, tin(IV)

tungstovanado-phosphate, titanium tungstate, thorium tungstate,

iron(III) tungstate, chromium tungstate, bismuth tungstate, antimony

tungstate. I have also compared my two other ion-exchangers

(Bismuth(III) iodotungstate and Antimony(III) tungstosilicate) with

seven other ion exchangers on the basis of IEC, selectivity and nature.

It can be seen from the table 5.2 that my exchangers show higher ion

exchanger capacity. Similar comparison of my ion-exchanger

antimony(III) iodovanadate with five otherexchangers. Ion-exchange

capacity of my exchanger is highest (Table 5.1).

On comparing my ion-exchanger (Bismuth(III) iodotungstate)

with four other reported ion-exchangers on the basis of loss in I.E.C

from a temperature of 1000C to 2000C I found that my exchanger

exhibited very small loss in I.E.C in comparison to others (refer table

5.3).

Effect of temperature on IEC of different ion exchangers

including my exchanger (AIV) was studied. The studies revealed that

my exchanger exhibit better resistance to heat than others (Table 5.4

and Fig. 5.1).

On the basis of the above analysis it can easily be concluded

that my ion-exchangers are far superior to some of the reported ion

exchangers. The conclusion itself proves the worth of the work.


The present work includes synthesis, characterization and

application of three new inorganic cation exchangers. The work can be

expanded by either modifying or introducing the techniques. Some of

the suggestions are given as under:

1. In the present work simple mode of synthesis is adopted the

synthesis can be tried by refluxing the reactants.Refluxing may

produce the material with improved properties.

2. In the present work PH of the resulant solutions obtained by

intermixing of the reactants was maintained one. The variation in

PH of the resultant solutions may be tried to find better materials.

3. I have synthesized inorganic cation exchangers. Synthesis of

hybrid cation exchangers can be done by taking some

organic compounds.

4. Ion-exchanger bed of one ion-exchanger is tried at one time in

the present work. Mixed bed of the cation exchangers can be

used for different applications.

5. Chemical stability against many more chemicals of different

concentrations can be studied. The loss of components of the

exchanger can be determined and therefore the loss of the

structure of the exchanger can be studied.


6. Distribution studies for many moremetal ions can be done and

Kd values for them can be calculated. Their values will help in

finding the selectivity of for metal ions.

7. In the distribution studies more metal ion pairs can be seen and

binary separations can be performed.

8. Though the removal of some metal ions is done with the help of

the three new ion-exchangers, yet removal of some more other

metal ions can be performed.

9. Water softening can be achieved with the help of the

synthesized ion exchangers.

10. Different antacid tablets can be analysed to see the percentage

of Mg2+ (magnesium ions).

11. The exchanger can be analysed quantitatively and then the

empirical formula can be established.

12. Exhausted exchangers can be regenerated to reuse.

Regeneration capacity can also be studied.

13. Potentiometric titration can be performed.

14. Kinetic study may be the part of the work.


TABLE 5.1


COMPARATAIVE STUDY O

FANTIMONY(III)IODOVANADATEWITHFIVEOTHEREXCHANGERS

Sl.

No.

Inorganicionexchanger I.E.C

at 100

I.E.C. LossinLEC

% loss

2. Zirconium(IV)tungstoiodophosp 1.82 1.60 0.22 12.08

3. Tin(IV)tungstovanadophosphate 1.80 1.50 0.30 16.66

4. Zirconium(IV)iodophosphate 1.60 1.40 0.20 12.6

5. Zirconium(IV)iodomolybdate 1.30 1.00 0.30 23.07

TABLE 5.2


COMPARATAIVE STUDY OF BISMUTH(III)DOTUNGSTATE

Sl.

No.

Material/IonExchanger Typeof IEC Selectivity

2. Antimony(III)tungstosilicate Amorphous 0.78 Ni(II), Pb(II)

3. Zirconiumtungstate Semi-transparant - Cs(I),R.K.(I),Na(I)

4. Tin(IV)tungstate Amorphous 0.58 Ba(II),Sr(II),Pb(II),Cu(II)

5. Titaniumtungstate Amorphous 0.4-0.76 Cs(I),Mg(I),Ca(II)

6. Thoriumtungstate Amorphous 0.46 Cs(I),K(I),Na(I)

7. Iron(III)tungstate Amorphous 0.86 Ce(IV)

8. Chromiumtungstate Amorphous 0.02 Th(IV), Hf(IV)

9. Bismuthtungstate - 0.75 Pb(II)


TABLE 5.3

COMPARATAIVE STUDY OF ISMUTH(III)

Sl.

No.

Inorganicionexchanger I.E.C

at 100

I.E.C. LossinLEC

% loss

2. Zirconium(IV)tungstoiodophosphate

1.82 1.60

0.22 12.08

3. Tin(IV)tungstovanadophosphate

1.80 1.50

0.30 16.66

4. Zirconium(IV)iodophosphate

1.60 1.40

0.20 12.6

5. Zirconium(IV)iodomolybdate

1.30 1.00

0.30 23.07


TABLE 5.4

COMPARATAIVE STUDY OFANTIMONY(III)

IODOVANADATEWITH FOUROTHEREXCHANGERS

Sl.

No.

Inorganicionexchanger IEC

at 40°C

IEC

at 50°C

IEC

at 100°C

IEC

at 200°C

IEC

at 300°C

IEC

at 400°C

IEC

at 5 00

IEC

at

°C

1

2.

Antimony(III)iodovanadateZirconium(IV)tu

ngstoidophosphateTin(IV)tungstovanadopho

sphateZirconium(IV)iodophosphateZirconiu

m(IV)iodomolybdate

-

2.20

1.83

2.64

-

2.5

1.82

2.40

1.60

1.89

1.35

1.77

1.00

0.80

0.90

-

0.7

8

-

0.6


TABLE 5.5

COMPARATAIVE STUDY

OFAIVWITH FOUOTHEREXCHANGERS


REFERENCES 1. Singh Premvir, Rawat J.P. and Rahman N.; Talanta (2002) 1-10.

(ZIV) 2. Mishra N.K.; J. Indian Chem. Soc. Vol. 80, July 2003, PP. 714-

716. 3. Nabi S.A., Usmani S. and Rehman N.; 1996. Ann. Chim 2/521

(ZIP). 4. Nabi S.A. and Siddiqui W.A.; 1986 Bull. Chem. Soc. JPh 59,

2003. 5. Siddiqui Weqar Ahmad and Khan Shakil Ahmad; Bull. Maer.

Sci., Vol. 30, No. 1 February 2007, PP. 2007 (TTVP) 6. Qureshi S.Z. and Rehman N.; 1987a Bull. Chem. Soc. Fr. 6 959.


LIST OF PUBLISHED RESEARCH PAPERS

1. Ion exchange capacity determination of Antimony(III) molybdate

a synthesized inorganic material and its characterization

Published in International Transactions in Applied

Sciences.April-June 2010, Volume2, No-2, PP.331-341.

2. Synthesis, Characterization and Analytical Application of

Antimony (III) tungstosilicate an inorganic ion exchanger.

Published in International Transactions in Applied

Sciences.April-June 2011, Volume 3, No-2, P.P. 191-198.

LIST OF PRESENTED RESEARCH PAPERS

1. ‘Synthesis and Characterization of Bismuth(III) iodotungstate, An

Exchanger’. Presented in ‘International Conference on Green

Technologies for Greener Environment’ on January 27th-30th,

2010, C.C.S. University, Meerut.


2. ‘Synthesis and Characterization of Antimony(III) iodovanadate’.

Presented in ‘National Conference on Recent Aspects of

Biological and Medicinal Chemistry’ on 20th & 21st February,

2010, Lajpat Rai Post-Graduate College, Sahibabad

(Ghaziabad) U.P.

3. ‘Synthesis and Characterization of Antimony(III) tungstosilicate

an Inorganic ion exchanger’. Presented in ‘2nd National Seminar

on Recent Trends in Advancement of Mathematical and Physical

Sciences’ on 30-31 January, 2010 at D.N. College, Meerut.

4. ‘Analytical Separation of Toxic Metal from Polluted water using

ion exchanges’. Presented in National Conference Environment

Problems & their Remedial Measure on 24-26 March, 2012 at

Ch. Charan Singh University, Meerut.

5. ‘Water Quality Situation of Some Indian Rivers’. Presented in

National Symposium on Green Technology for sustainable Development on 18 April, 2012 at Radha Govind group of Institutions, Institute of Informatics & Management Sciences.


LIST OF SEMINARS/CONFERENCES/ SYMPOSIUMS ATTENDED

1. National Seminar on Recent Trends in Advancement of

Mathematical & Physical Sciences on 6th November, 2006 at D.N. (P.G.) College, Meerut.

2. National Seminar on “Environment & Human Concern” on

February 17, 2008 at Deva Nagri College, Meerut. 3. National Symposium on Environment and Sustainable

Development on November 14, 2008 at Meerut College, Meerut. 4. National Conference on Recent Aspects of Biological and

Medicinal Chemistry on 20th & 21st February 2010, Lajpat Rai Post-Graduate College, Sahibabad, Ghaziabad.

5. International Year of Chemistry 2011 (Unesco& IUPAC) on

02.12.2011, at Meerut College, Meerut (Co-operation in Quiz Contest held on 2.12.2011). 6. National Seminar on Recent Trends in Advancement of

Mathematical and Physical Sciences on 17-18 March 2012 at Deva Nagari College, Meerut.


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