Research Article Removal of Hardness of Earth Alkaline ...downloads.hindawi.com/archive/2014/621794.pdf · Research Article Removal of Hardness of Earth Alkaline Metals from Aqueous

Research ArticleRemoval of Hardness of Earth Alkaline Metals fromAqueous Solutions by Ion Exchange Method

Gulten Cetin

Chemistry Department Faculty of Science and Art Yildiz Technical University Campus of Davutpasa Esenler34220 Istanbul Turkey

Correspondence should be addressed to Gulten Cetin gultencetin612gmailcom

Received 28 November 2013 Accepted 31 December 2013 Published 23 February 2014

Academic Editors N Egashira V A Lemos and A Lewenstam

Copyright copy 2014 Gulten CetinThis is an open access article distributed under the Creative Commons Attribution License whichpermits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

An ion exchange processwas introduced as an approach for softening of artificial hardwater solutions A strong acid cation exchangeresin Amberlite IR 120 [Na+] was used to reduce the hardness of water with thematrix of styrene-divinylbenzene copolymer havingfunctional group as sulfonateThe ion exchange behavior of the ions of calcium andmagnesium in synthetic solutions of hard waterwas investigated with the variables depending on pH stirrer speed of the solutions and amount of the resin as a function of contacttime between resin phase and hard water solution The maximum ion exchange capacity was found to be 68mgg for Ca(II) and12mgg forMg(II) at pH 30Themethod is a simple and efficient one to remove calcium andmagnesium hardness from hard watersolutions with the resin having more selectivity for calcium

1 Introduction

Theexistence of the solubleCa(II) andMg(II) salts has causedunsuitable behavior of hard water solutions for drinkingwatering and the purposes of industrialThe ionic impuritiescan lead to problems in cooling and heating systems steamgeneration and manufacturing The high calcium and mag-nesium concentrations have resulted in clogging of pipelinesand heat exchangers through scaling as the form at carbonatesulfate or phosphate precipitates Therefore the necessity ofobtaining water having low level of hardness has taken placeinside important occupational areas for industries such asleather production [1] The common methods used forremoval of the metals of earth alkaline from aqueous solu-tions and softening of water can be classified as chemicalprecipitation ultrafiltration reverse osmosis electrodialysisadsorption and ion exchange [2ndash4] Water softening usingelectrochemical techniques has gained attention [5] Thepacked bed of polypyrrolepolystyrene sulfonate electrode-posited porous carbon electrode has been used for con-tinuous water softening from flowing artificial hard watersolutions [6]

The ion exchange resins have numerous commercial andindustrial uses particularly in water purification and removal

of metal ions at very low concentrations in chemical processof industries [7] Some polymeric resins having strongly acidsulfonic or weakly acid carboxylic functionalities are usuallyused in ion exchange processes [8ndash11] A method has beenfocused on the combination of ultrasound and ion exchangefor removal of hardness of calcium and magnesium fromwater [12] Somemethods have been conducted for removingCa(II) and Mg(II) from water by using chelating resins withhigh selectivity [13ndash15] The exchange of Ca(II) and Mg(II)from LiHCO

3solution was studied with Amberlite IRC 747

[16] Applications of polymeric resins containing iminodi-acetate have been investigated from aqueous solutions forrecovery of Ca(II) and Mg(II) [17ndash23] Amberlite IRC 748as K+ form was used from potassium chromate solution forremoval of Ca(II) and Mg(II) [24] A study was performedon softening of waste geothermal water using ion exchangeresins [25]

There are some studies by ion exchange technology usingthe resin of Amberlite IR 120 Some of them for Ca(II)removal [26] and magnesium adsorption [27] have beeninvestigated by using empirical kinetic models

In the present work the main objective of the study is toremove the magnesium and calcium hardness from syntheticsolutions of hard water The selective adsorption equilibrium

Hindawi Publishing CorporationISRN Analytical ChemistryVolume 2014 Article ID 621794 7 pageshttpdxdoiorg1011552014621794

2 ISRN Analytical Chemistry

(a) (b)

Figure 1 The basket of the resin

for earth alkaline metals was investigated under differentconditions such as pH stirring speed of the solutions andamount of the resin as a function of contact time between thephase of resin and synthetic hard water solutions The exam-ined method was applied for removal of calcium and magne-siumhardness of tapwater obtained from research laboratoryof YILDIZ Technical University Faculty of Science and ArtAnalytical Chemistry Department Esenler Istanbul Turkey

2 Experimental

21 Materials The inorganic chemicals including CaCI2

2H2O MgCI

26H2O HCI and NaOH were obtained from

Merck (Darmstadt Germany) in analytical grade All solu-tions were prepared using bidistilled water

22 Ion Exchange Resin The resin of Amberlite IR 120 [Na+][28] was used as a strongly acid cation exchanger havingcopolymer of styrene and divinylbenzene with functionalgroups of SO

3

minusNa+ in the physical form gel typeThe proper-ties and suggested operating conditions of the resin have beenshown in Tables 1(a) and 1(b)

The resin was washed three times with the solutions ofrespectively 10molLHCI and 10molLNaOHbefore its useto remove or reduce possible organic and inorganic impuri-ties It was then washed with bidistilled water and convertedto H+ form from Na+ by flushing in fixed bed with 10molLHCIThe resin in H+ form was finally washed with water andused throughout the experiments

23 Preparing of the Solutions of Synthetic Hard Water Thesynthetic solutions of hard water have been prepared as stocksolution in the volume of 50 L The volume of 950mL of thestock solution was taken to the batch reactor and after the pHof the solution was adjusted to desired value the solution wastransferred to the flask in the volume of 10 L by diluting tothe volume and it was used as synthetic solution of hardwaterThe hardness of calcium andmagnesiumof the solutionswith

Table 1 Manufacturer data of the resin [28]

(a) The properties of the resin Amberlite IR 120 [Na+]

Physical form Amber spherical beadsMatrix Styrene-divinylbenzene copolymerFunctional group SulfonateIonic form as shipped Na+

Total exchange capacity gt200 eqL (Na+ form)Moisture holding capacity 45 to 50 (Na+ form)Shipping weight 840 gLUniformity coefficient lt19Harmonic mean size 0600 to 0800mmlt0300mm 2 maxMaximum reversible swelling Na+ rarr H+ lt 11

(b) Suggested operating conditions of the resin

Maximum operating temperature 135∘CMinimum bed depth 700mmService flow rate 5 to 40 BVhRegenerant HCI H2SO4 NaCILevel (gL) 50 to 150 60 to 240 80 to 250Concentration () 5 to 8 07 to 6 10Minimum contact time 30 minutesSlow rinse 2 BV at regeneration flow rateFast rinse 2 to 4 BV at service flow rate

state of initial and equilibrium is shown as degree of Frenchhardness (FH) in Tables 4 5 and 6 and in Figure 1

24 Preparing of the Solutions for Analysis The volume of05mL of the solution of synthetic hard water was taken tothe flask in the volume of 100mL and diluted to the volumeby distilled water

25 Procedure The batch experiments were carried outto determine the efficiency of removal of calcium and

ISRN Analytical Chemistry 3

Table 2 Instrumental parameters for determination of calcium andmagnesium [29]

Instrumental parameters Calcium MagnesiumWave length (nm) 44267 44267Slit width (nm) 27 27Fuel Acetyleneair AcetyleneairLamp current (mA) 20 20Optimum working range (05ndash25) mgL (02ndash10) mgL

magnesium hardness from synthetic solution of hard waterThe sample of 50 g of the resin in hydrogen form was putinto basket of the resinThe basket of the resin was inserted tothemechanical stirrer with themodel of Heildolph RZR 2021The mechanical stirrer was placed into the vessel of reactioncontaining synthetic solution of hard water in the volume of10 L The basket stirrer was moved in the solution for onehour while the stirrer works at constant speedThe apparatusof the resin basket has been shown in Figure 1

This procedure was applied by using synthetic solutionsof hard water having comparable amount of calcium andmagnesium hardness The samples of 500120583L were takenfrom solution to measure concentration of the calcium andmagnesium for each 10min 20min 30min 40min 50minand 60minThe samples were diluted to 100mL and acidifiedwith solution of nitric acid The concentrations of calciumand magnesium were determined by an atomic absorptionspectrophotometer with a model of Perkin Elymer and air-acetylene flame The balance of the model of Sartorius A 200S was used for the all weights Table 2 shows the instrumentalparameters for determination of calcium and magnesium byatomic absorption spectrophotometry

3 Results and Discussion

31 Method for Removal of Calcium(II) and Magnesium(II)Hardness The ion exchange process was developed toremove calcium and magnesium hardness from synthetichard water solutions by using the resin of Amberlite IR 120in H+ form

The following reactions show that the resin matrix hasbeen converted to the H+ form from Na+ and the exchangereaction of calcium and magnesium has been summarized

RndashSO3

minusNa+ +HCI 997888rarr RndashSO3

minusH+ +Na+ + CIminus

2Rndash(SO3

minusH+)2+ Ca2+ +Mg2+

997888rarr Rndash(SO3

minus)2Ca2+ + Rndash(SO

3

minus)2Mg2+ + 4H+

(1)

The resinrsquos behavior is different for sorption of calciumand magnesium ions in solution and it is more selective forcalcium thanmagnesium and exchange capacity is more highfor calcium Figures 2 and 3 show this phenomena

The method of atomic absorption spectrophotometricwas used for determination of initial and equilibrium concen-trations of ions of calcium andmagnesium in solution of hardwater by using the equations of calibration curve as it is shownin Table 3

0

20

40

60

80

100

120

140

0 10 20 30 40 50 60 70Time (min)

Har

dnes

s of

calc

ium

and

mag

nesiu

m (F

H)

Magnesium pH 20Magnesium pH 30Magnesium pH 40Magnesium pH 50

Calcium pH 20Calcium pH 30Calcium pH 40Calcium pH 50

Figure 2The exchange of hardness of calcium and magnesium as afunction of initial pH of the solution (the amount of resin 50 g thestirring speed of the solution 115 rpm)

0

20

40

60

80

100

120

0 10 20 30 40 50 60 70Time (min)

Rem

oval

of h

ardn

ess (

)



Figure 3 The removal of the hardness of calcium and magnesiumas a function of initial pH of the solution (the amount of resin 50 gthe stirring speed of the solution 115 rpm)

Table 3 The characteristics of the calibration curves

Earth alkalinemetal

Equation ofcalibration curve

Coefficient ofregression (1198772)

Calcium 119860 = 00328119862 minus 00018 09994Magnesium 119860 = 03895119862 + 00145 09985

The sorption process of the resin for calcium and magne-siumwas investigated under experimental conditions such ascontact time between resin and aqueous solution pH stirringspeed of the solution of hard water and amount of the resin


Table 4 Experimental conditions depend on effect of pH for removal of hardness of calcium and magnesium

pHStirringspeed(rpm)

Resindosage(g)

Initial hardness ofcalcium (FH)

Hardness of calcium inequilibrium (FH)

Initial hardness ofmagnesium (FH)

Hardness of magnesium inequilibrium (FH)

2 115 5 7912 367(60min) 12489 9983

(60min)

3 115 5 8375 000(60min) 12489 9680

(60min)

4 115 5 8375 000(60min) 11828 10077

(60min)

5 115 5 8525 000(60min) 10290 9050

(60min)

Table 5 ((a) (b) and (c)) The exchange of pH of the solution inequilibrium depends on contact time with the resin according toexperimental conditions

(a)

Contact time with the resin(min) 0 10 20 30 40 50 60

pH(resin dosage 50 g)(stirring speed 115 rpm)

200 177 174 173 172 172 172


300 203 198 196 195 194 193


400 222 218 217 216 214 211


500 235 229 227 225 220 211

(b)



300 284 225 223 222 221 221


300 218 217 217 216 216 214

(c)



303 205 204 203 202 202 201


302 200 195 193 192 191 191

32 Effect of Contact Time between Resin and Synthetic Solu-tion of Hard Water on Removal of Hardness of Calcium andMagnesium The contact time is an important factor in theprocess of removal of calcium and magnesium from solution

of synthetic hard water The batch experiments were carriedout at different contact times as 0 10 20 30 40 50 and60min with 50 g of the resin and stirring rate of the solutionas 115 rpm in the pH range between 20 and 50 The equilib-rium was established for 60min

The uptake of Ca(II) and Mg(II) ions and removal ofhardness of calcium andmagnesium increase rapidly duringrespectively 20min and 10min at first then the removal ofmagnesium hardness increases slowly until the equilibriumstate was reached as the active sites on the sorbent were filledby ions of calcium The obtained results has shown that theequilibrium is reached after 20min under experimental con-ditions as mentioned Figure 2 shows the exchange of hard-ness of magnesium and calcium from synthetic solutions ofhard water with the pH range between 2 and 5

33 Effect of pH on Removal of Hardness of Calcium andMag-nesium The pH of the solution of hard water has significanteffect on affinity of the resin for calcium andmagnesium ionsThe sorption of ions of Ca(II) and Mg(II) and removal ofhardness of calcium and magnesium from solution of hardwater were studied with the resin of Amberlite IR 120 [H+]at initial pH range between 20 and 50 The initial pH ofthe solution of hard water was controlled with pH meter byadding solutions of hydrochloric acid and sodium hydroxideIn the experiment the temperature stirring speed and max-imum contact time were kept constant at 298K 115 rpm and60min Figure 3 shows that the removal amount of hardnessof calcium and magnesium from synthetic solutions of hardwater depends on contact time with the resin phase in the pHrange of 20 and 50

While the amount of removal of calcium hardness hasremarkably increased from 40 to 100 the amount ofremoval of magnesium hardness is more restrictive up toabout 12 for equilibrium of 20min at higher pH than 20The maximum uptake capacity for calcium and magnesiumhas been determined respectively as 68mgg (pH 30) and12mgg (pH 30) This result has shown that the resin hashigher capacity of uptake and selectivity for adsorption ofcalcium than magnesium Therefore there is a considerationthat the adsorption of calcium ions with anionic functionalgroups on the surface of the resin has a priority to compare


Table 6 Experimental conditions depend on effect of stirring speed for removal of hardness of calcium and magnesium


Resindosage(g)





3 78 5 9250 5956(60min) 13435 10835

(60min)

3 115 5 8375 000(60min) 12489 9680

(60min)

3 148 5 8005 000(60min) 12425 9500

(60min)

Table 7 Experimental conditions depend on effect of amount of the resin for removal of hardness of calcium and magnesium


Resindosage(g)





3 115 50 8375 000(60min) 12489 9680

(60min)

3 115 75 9790 000(60min) 12250 8225

(60min)

3 115 10 9340 000(60min) 11965 3360

(60min)

with magnesium and the sorption of magnesium has a disad-vantage with less number of binding sites Tables 4 and 5(a)ndash5(c) show respectively experimental conditions concernedwith effect of pH for removing of hardness of calcium andmagnesium from synthetic solutions of hard waters and pHvalues of solution in equilibrium depending on initial pHof the solution and contact time with the resin phase accord-ing to experimental conditions

34 Effect of Stirring Speed on Removal of Hardness of Calciumand Magnesium The effect of stirring speed of the syntheticsolution of hard water on removal of hardness of calcium andmagnesium was examined with agitation speed between 78and 148 rpm at pHof the solution of 30 with the resin amountof 50 g The results show that while stirring speed of thesolution increases the hardness of calcium and magnesiumhas reduced and as seen in Figure 4 the removal amount ofhardness of calcium and magnesium has risen The resultsindicate that the agitation speed of the solution of hard waterhas an impact on adsorption of calcium and magnesium andremoval of hardness degrees

Table 6 shows experimental conditions concerned witheffect of stirring speed for removing of hardness of calciumand magnesium from synthetic solutions of hard waters

35 Effect of Amount of the Resin on Removal of Hardness ofCalcium and Magnesium The removal amount of hardnessof calcium and magnesium (Figure 5) from synthetic solu-tions of hard water was examined in relation to the amount ofthe resin between 5 and 10 g under experimental conditionssuch that pH of the solution is 30 and the stirrer speed of thesolution is 115 rpm

According to the results obtained the removal efficiencyof calcium and magnesium hardness increases with rising

0

20

40

60

80

100

120

0 10 20 30 40 50 60 70Time (min)

Rem

oval

of h

ardn

ess (

)

Magnesium agitation rate 78 rpm

Calcium agitation rate 78 rpm

Magnesium agitation rate 115rpmMagnesium agitation rate 148rpm

Calcium agitation rate 115rpmCalcium agitation rate 148 rpm

Figure 4 The removal of the hardness of calcium and magnesiumas a function of agitation speed of the solution (the amount of resin50 g the initial pH of the solution 30)

amount of the resinThe amount of the resin provides a greatof ion exchange sites to replace of earth alkaline metals for afixed initial concentration of calcium and magnesium in thesolution of hard water The amount of the resin is an impor-tant parameter to obtain the quantitative uptake of calciumand magnesium ions Table 7 shows experimental conditionsconcerned with effect of resine dosage for removing hardnessof calcium and magnesium from synthetic solution of hardwaters


0

20

40

60

80

100

120

0 10 20 30 40 50 60 70Time (min)

resin dosage 50 Magnesium g

resin dosage 50 Calcium gresin dosage 75 Calcium g

gresin dosage 75 MagnesiumMagnesium resin dosage100 g

Calcium resin dosage 100 g

Rem

oval

of h

ardn

ess (

)

Figure 5 The removal of the hardness of calcium and magnesiumas a function of amount of the resin (the initial pH of the solution30 the stirring speed of the solution 115 rpm)

4 Conclusion

Ion exchange technique has proved to be advantageous overother technologies Amberlite IR 120 a strong acid cationexchange resin in sodium form is a low cost ion exchangeresin and the experiments have shown that the resin is effec-tive for removal of hardnesses of calcium in the presence ofmagnesium and softening of waters

In this study the effects of pH and stirring speed of thesolution and dosage of the resin were searched to remove ofhardness level of calcium and magnesium as a function ofcontact time between the resin and solution of hard waterThe optimum operation conditions were determined as pHof the solution is 30 agitation speed of the solution is 115 rpmamount of the resin is 10 g and ratio of resinsolution is1 g100mL The maximum removal efficiency was achievedfor calcium and magnesium respectively as 100 and 70with contact time of 20min The results have shown thatthe ion exchange rate and capacity of the resin are higherfor calcium than magnesium as a competition of sorption ofcalcium and magnesium and hydrogen ions has occured forresin sites and exchange of calcium has formed in preferenceto ions of magnesium and hydrogen The difference of selec-tivity of the resin for sorption of calcium andmagnesium ionshas great effect on removal of hardness of calciumwith the pHrange higher than 20

This study has been introduced as a method for removalof calcium from aqueous solutions in the presence of mag-nesium and pH range between 20 and 50 The feasibleresults have been reached for removal of hardness of calciumand magnesium of tap water obtained from Research Lab-oratory of YILDIZ Technical University Analytical Chem-istry Department Istanbul Turkey The resin of Amberlite

IR 120 [Na+] can be used for treatment applications includingsoftening

Conflict of Interests

The author declares that there is no conflict of interestsregarding the publication of this paper

References

[1] A F Viero A C R Mazzarollo K Wada and I C TessaroldquoRemoval of hardness and COD from retanning treated effluentby membrane processrdquo Desalination vol 149 no 1ndash3 pp 145ndash149 2002

[2] Z C Lei K Qian and L H Liu Principles and Applications ofIndustrial Water Treatment Chemical Industry Press BeijingChina 2003

[3] P N CheremisinoffHandbook of Water and Wastewater Treat-ment Technologies Butterworth-Heinemann New York NYUSA 2001

[4] S Rengaraj J-W Yeon Y Kim Y Jung Y-K Ha and W-HKim ldquoAdsorption characteristics of Cu(II) onto ion exchangeresins 252H and 1500HKinetics isotherms and error analysisrdquoJournal of Hazardous Materials vol 143 no 1-2 pp 469ndash4772007

[5] C Gabrielli G Maurin H Francy-Chausson P Thery T T MTran and M Tlili ldquoElectrochemical water softening principleand applicationrdquo Desalination vol 201 no 1ndash3 pp 150ndash1632006

[6] M M Saleh ldquoWater softening using packed bed of polypyrrolefrom flowing solutionsrdquo Desalination vol 235 no 1ndash3 pp 319ndash329 2009

[7] E Pehlivan and T Altun ldquoThe study of various parametersaffecting the ion exchange of Cu2+ Zn2+ Ni2+ Cd2+ and Pb2+from aqueous solution on Dowex 50W synthetic resinrdquo Journalof Hazardous Materials vol 134 no 1ndash3 pp 149ndash156 2006

[8] E Maliou M Malamis and P O Sakellarides ldquoLead and cad-mium removal by ion exchangerdquoWater Science and Technologyvol 25 no 1 pp 133ndash138 1992

[9] S Ahmed S Chughtai and M A Keane ldquoThe removal ofcadmium and lead from aqueous solution by ion exchange withNa-Y zeoliterdquo Separation and Purification Technology vol 13no 1 pp 57ndash64 1998

[10] J P Chen and LWang ldquoCharacterization of a Ca-alginate basedion-exchange resin and its applications in lead copper and zincremovalrdquo Separation Science and Technology vol 36 no 16 pp3617ndash3637 2001

[11] P Outola H Leinonen M Ridell and J Lehto ldquoAcidbase andmetal uptake properties of chelating and weak base resinsrdquoSolvent Extraction and Ion Exchange vol 19 no 4 pp 743ndash7562001

[12] M H Entezari and M Tahmasbi ldquoWater softening by combi-nation of ultrasound and ion exchangerdquo Ultrasonics Sonochem-istry vol 16 no 3 pp 356ndash360 2009

[13] K L Reece and R L Moss ldquoRemoval of contaminatingcalcium from buffer solutions used in calcium binding assaysrdquoAnalytical Biochemistry vol 365 no 2 pp 274ndash276 2007

[14] D K Huggins P B Queneau R C Ziegler and H H K NautaldquoIon exchange purification of ammoniummolybdate solutionsrdquoHydrometallurgy vol 6 no 1-2 pp 63ndash73 1980


[15] K Vaaramaa and J Lehto ldquoRemoval of metals and anions fromdrinking water by ion exchangerdquo Desalination vol 155 no 2pp 157ndash170 2003

[16] W-T Yi C-Y Yan and P-H Ma ldquoRemoval of calcium andmagnesium from LiHCO

3solutions for preparation of high-

purity Li2CO3by ion-exchange resinrdquoDesalination vol 249 no

2 pp 729ndash735 2009[17] Y Ding and Z Ji Production and Application of Chromate

Compounds Chemical Industry Press Beijing China 2003[18] S J Manio ldquoMethod for Reducing Metal Ion Concentration in

Brine Solutionrdquo US Patent 6103092 2000[19] P Woodberry G Stevens I Snape and S Stark ldquoRemoval of

metal contaminants from salinewaters at low temperature by animinodiacetic acid ion-exchange resin Thala Valley Tip CaseyStation Antarcticardquo Solvent Extraction and Ion Exchange vol23 no 2 pp 289ndash306 2005

[20] A Agrawal and K K Sahu ldquoInfluence of temperature on theexchange of alkaline earth and transition metals on iminodiac-etate resinrdquo Solvent Extraction and Ion Exchange vol 23 no 2pp 265ndash287 2005

[21] A Agrawal K K Sahu and J P Rawat ldquoKinetic studies onthe exchange of bivalent metal ions on amberlite IRC-718mdashaniminodiacetate resinrdquo Solvent Extraction and Ion Exchange vol21 no 5 pp 763ndash782 2003

[22] A Agrawal and K K Sahu ldquoSeparation and recovery of leadfrom a mixture of some heavy metals using Amberlite IRC 718chelating resinrdquo Journal ofHazardousMaterials vol 133 no 1ndash3pp 299ndash303 2006

[23] M Laikhtman J Riviello and J S Rohrer ldquoDetermination ofmagnesium and calcium in 30 sodium chloride by ion chro-matography with on-line matrix eliminationrdquo Journal of Chro-matography A vol 816 no 2 pp 282ndash285 1998

[24] Z Yu T Qi J Qu L Wang and J Chu ldquoRemoval of Ca(II)and Mg(II) from potassium chromate solution on AmberliteIRC 748 synthetic resin by ion exchangerdquo Journal of HazardousMaterials vol 167 no 1-3 pp 406ndash412 2009

[25] C Ghergheles V Ghergheles T Romocea et al ldquoSoftening ofwaste geothermal water using ion exchange resins for envi-ronmental protectionrdquo Journal of Environmental Protection andEcology vol 13 no 3 pp 1553ndash1559 2012

[26] C Ozmetin O Aydin M M Kocakerim M Korkmaz andE Ozmetin ldquoAn empirical kinetic model for calcium removalfrom calcium impurity-containing saturated boric acid solutionby ion exchange technology using Amberlite IR-120 resinrdquoChemical Engineering Journal vol 148 no 2-3 pp 420ndash4242009

[27] C Ozmetin and O Aydin ldquoA semi-empirical model for adsorp-tion of magnesium ion from magnesium impurity-containingsaturated boric acid solutions on amberlite IR-120 resinrdquo Frese-nius Environmental Bulletin vol 16 no 7 pp 720ndash725 2007

[28] Rohm and Haas Company ldquoWater Treatment Resin (IndustrialGrade)rdquo Product Data Sheet IE-489 EDS Corporate Head-quarters 100 Independence Mall West Philadelphia USA 1998

[29] Analytical Methods Varian Techtron Pty Limited MulgraveVictoria Australia Publication no 85-100009-00 1989

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy


Carbohydrate Chemistry

International Journal of


Journal of

Chemistry


Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of


The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of


Chromatography Research International


Applied ChemistryJournal of



Theoretical ChemistryJournal of


Journal of

Spectroscopy

Analytical ChemistryInternational Journal of


Journal of


Quantum Chemistry


Organic Chemistry International

ElectrochemistryInternational Journal of



CatalystsJournal of


(a) (b)

Figure 1 The basket of the resin

for earth alkaline metals was investigated under differentconditions such as pH stirring speed of the solutions andamount of the resin as a function of contact time between thephase of resin and synthetic hard water solutions The exam-ined method was applied for removal of calcium and magne-siumhardness of tapwater obtained from research laboratoryof YILDIZ Technical University Faculty of Science and ArtAnalytical Chemistry Department Esenler Istanbul Turkey

2 Experimental

21 Materials The inorganic chemicals including CaCI2

2H2O MgCI

26H2O HCI and NaOH were obtained from

Merck (Darmstadt Germany) in analytical grade All solu-tions were prepared using bidistilled water

22 Ion Exchange Resin The resin of Amberlite IR 120 [Na+][28] was used as a strongly acid cation exchanger havingcopolymer of styrene and divinylbenzene with functionalgroups of SO

3

minusNa+ in the physical form gel typeThe proper-ties and suggested operating conditions of the resin have beenshown in Tables 1(a) and 1(b)

The resin was washed three times with the solutions ofrespectively 10molLHCI and 10molLNaOHbefore its useto remove or reduce possible organic and inorganic impuri-ties It was then washed with bidistilled water and convertedto H+ form from Na+ by flushing in fixed bed with 10molLHCIThe resin in H+ form was finally washed with water andused throughout the experiments

23 Preparing of the Solutions of Synthetic Hard Water Thesynthetic solutions of hard water have been prepared as stocksolution in the volume of 50 L The volume of 950mL of thestock solution was taken to the batch reactor and after the pHof the solution was adjusted to desired value the solution wastransferred to the flask in the volume of 10 L by diluting tothe volume and it was used as synthetic solution of hardwaterThe hardness of calcium andmagnesiumof the solutionswith

Table 1 Manufacturer data of the resin [28]

(a) The properties of the resin Amberlite IR 120 [Na+]

Physical form Amber spherical beadsMatrix Styrene-divinylbenzene copolymerFunctional group SulfonateIonic form as shipped Na+

Total exchange capacity gt200 eqL (Na+ form)Moisture holding capacity 45 to 50 (Na+ form)Shipping weight 840 gLUniformity coefficient lt19Harmonic mean size 0600 to 0800mmlt0300mm 2 maxMaximum reversible swelling Na+ rarr H+ lt 11

(b) Suggested operating conditions of the resin

Maximum operating temperature 135∘CMinimum bed depth 700mmService flow rate 5 to 40 BVhRegenerant HCI H2SO4 NaCILevel (gL) 50 to 150 60 to 240 80 to 250Concentration () 5 to 8 07 to 6 10Minimum contact time 30 minutesSlow rinse 2 BV at regeneration flow rateFast rinse 2 to 4 BV at service flow rate

state of initial and equilibrium is shown as degree of Frenchhardness (FH) in Tables 4 5 and 6 and in Figure 1

24 Preparing of the Solutions for Analysis The volume of05mL of the solution of synthetic hard water was taken tothe flask in the volume of 100mL and diluted to the volumeby distilled water

25 Procedure The batch experiments were carried outto determine the efficiency of removal of calcium and









RndashSO3



2Rndash(SO3




3

minus)2Mg2+ + 4H+

(1)



0

20

40

60

80

100

120

140

0 10 20 30 40 50 60 70Time (min)

Har

dnes

s of

calc

ium

and

mag

nesiu

m (F

H)




0

20

40

60

80

100

120

0 10 20 30 40 50 60 70Time (min)

Rem

oval

of h

ardn

ess (

)





Earth alkalinemetal








Resindosage(g)





2 115 5 7912 367(60min) 12489 9983

(60min)

3 115 5 8375 000(60min) 12489 9680

(60min)

4 115 5 8375 000(60min) 11828 10077

(60min)

5 115 5 8525 000(60min) 10290 9050

(60min)


(a)



200 177 174 173 172 172 172


300 203 198 196 195 194 193


400 222 218 217 216 214 211


500 235 229 227 225 220 211

(b)



300 284 225 223 222 221 221


300 218 217 217 216 216 214

(c)



303 205 204 203 202 202 201


302 200 195 193 192 191 191









Resindosage(g)





3 78 5 9250 5956(60min) 13435 10835

(60min)

3 115 5 8375 000(60min) 12489 9680

(60min)

3 148 5 8005 000(60min) 12425 9500

(60min)



Resindosage(g)





3 115 50 8375 000(60min) 12489 9680

(60min)

3 115 75 9790 000(60min) 12250 8225

(60min)

3 115 10 9340 000(60min) 11965 3360

(60min)






0

20

40

60

80

100

120

0 10 20 30 40 50 60 70Time (min)

Rem

oval

of h

ardn

ess (

)








0

20

40

60

80

100

120

0 10 20 30 40 50 60 70Time (min)





Rem

oval

of h

ardn

ess (

)


4 Conclusion







References











































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of









RndashSO3



2Rndash(SO3




3

minus)2Mg2+ + 4H+

(1)



0

20

40

60

80

100

120

140

0 10 20 30 40 50 60 70Time (min)

Har

dnes

s of

calc

ium

and

mag

nesiu

m (F

H)




0

20

40

60

80

100

120

0 10 20 30 40 50 60 70Time (min)

Rem

oval

of h

ardn

ess (

)





Earth alkalinemetal








Resindosage(g)





2 115 5 7912 367(60min) 12489 9983

(60min)

3 115 5 8375 000(60min) 12489 9680

(60min)

4 115 5 8375 000(60min) 11828 10077

(60min)

5 115 5 8525 000(60min) 10290 9050

(60min)


(a)



200 177 174 173 172 172 172


300 203 198 196 195 194 193


400 222 218 217 216 214 211


500 235 229 227 225 220 211

(b)



300 284 225 223 222 221 221


300 218 217 217 216 216 214

(c)



303 205 204 203 202 202 201


302 200 195 193 192 191 191









Resindosage(g)





3 78 5 9250 5956(60min) 13435 10835

(60min)

3 115 5 8375 000(60min) 12489 9680

(60min)

3 148 5 8005 000(60min) 12425 9500

(60min)



Resindosage(g)





3 115 50 8375 000(60min) 12489 9680

(60min)

3 115 75 9790 000(60min) 12250 8225

(60min)

3 115 10 9340 000(60min) 11965 3360

(60min)






0

20

40

60

80

100

120

0 10 20 30 40 50 60 70Time (min)

Rem

oval

of h

ardn

ess (

)








0

20

40

60

80

100

120

0 10 20 30 40 50 60 70Time (min)





Rem

oval

of h

ardn

ess (

)


4 Conclusion







References











































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of




Resindosage(g)





2 115 5 7912 367(60min) 12489 9983

(60min)

3 115 5 8375 000(60min) 12489 9680

(60min)

4 115 5 8375 000(60min) 11828 10077

(60min)

5 115 5 8525 000(60min) 10290 9050

(60min)


(a)



200 177 174 173 172 172 172


300 203 198 196 195 194 193


400 222 218 217 216 214 211


500 235 229 227 225 220 211

(b)



300 284 225 223 222 221 221


300 218 217 217 216 216 214

(c)



303 205 204 203 202 202 201


302 200 195 193 192 191 191









Resindosage(g)





3 78 5 9250 5956(60min) 13435 10835

(60min)

3 115 5 8375 000(60min) 12489 9680

(60min)

3 148 5 8005 000(60min) 12425 9500

(60min)



Resindosage(g)





3 115 50 8375 000(60min) 12489 9680

(60min)

3 115 75 9790 000(60min) 12250 8225

(60min)

3 115 10 9340 000(60min) 11965 3360

(60min)






0

20

40

60

80

100

120

0 10 20 30 40 50 60 70Time (min)

Rem

oval

of h

ardn

ess (

)








0

20

40

60

80

100

120

0 10 20 30 40 50 60 70Time (min)





Rem

oval

of h

ardn

ess (

)


4 Conclusion







References











































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of




Resindosage(g)





3 78 5 9250 5956(60min) 13435 10835

(60min)

3 115 5 8375 000(60min) 12489 9680

(60min)

3 148 5 8005 000(60min) 12425 9500

(60min)



Resindosage(g)





3 115 50 8375 000(60min) 12489 9680

(60min)

3 115 75 9790 000(60min) 12250 8225

(60min)

3 115 10 9340 000(60min) 11965 3360

(60min)






0

20

40

60

80

100

120

0 10 20 30 40 50 60 70Time (min)

Rem

oval

of h

ardn

ess (

)








0

20

40

60

80

100

120

0 10 20 30 40 50 60 70Time (min)





Rem

oval

of h

ardn

ess (

)


4 Conclusion







References











































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of


0

20

40

60

80

100

120

0 10 20 30 40 50 60 70Time (min)





Rem

oval

of h

ardn

ess (

)


4 Conclusion







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










Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of

Documents

Research Article Removal of Hardness of Earth Alkaline ...downloads.hindawi.com/archive/2014/621794.pdf · Research Article Removal of Hardness of Earth Alkaline Metals from Aqueous