Hindawi Publishing CorporationJournal of ChemistryVolume 2013 Article ID 415280 6 pageshttpdxdoiorg1011552013415280

Research ArticleKinetics Equilibrium and Thermodynamic Studies onAdsorption of Methylene Blue by Carbonized Plant Leaf Powder

V Gunasekar and V Ponnusami

School of Chemical and Biotechnology SASTRA University anjavur 613401 India

Correspondence should be addressed to V Ponnusami vponnuchemsastraedu

Received 30 June 2012 Revised 8 August 2012 Accepted 13 August 2012

Academic Editor Cengiz Soykan

Copyright copy 2013 V Gunasekar and V Ponnusami is is an open access article distributed under the Creative CommonsAttribution License which permits unrestricted use distribution and reproduction in any medium provided the original work isproperly cited

Carbon synthesized from plant leaf powder was employed for the adsorption ofmethylene blue from aqueous effluent Effects of pH(2 4 6 8 and 9) dye concentration (50 100 150 and 200mgdm3) adsorbent dosage (05 10 15 and 20 gdm3) and temperature(303 313 and 323K) were studied e process followed pseudo-second-order kinetics Equilibrium data was examined withLangmuir and Freundlich isotherm models and Langmuir model was found to be the best tting model with high R2 and lowchi2 values Langmuir monolayer adsorption capacity of the adsorbent was found to be 6122 mgg From the thermodynamicanalysis ΔH ΔG and ΔS values for the adsorption of MB onto the plant leaf carbon were found out From the values of free energychange the process was found out to be feasible process From the magnitude of ΔH the process was found to be endothermicphysisorption

1 Introduction

Synthetic dyes in large variety and quantity are used byseveral industries for coloring their products [1ndash3] Con-siderable amount of the dyes added in the process remainunconsumed and ultimately nd their way to water bodiesPresence of dyes in water bodies poses serious threat to theenvironment as the color affects the nature of the water andmakes it unsuitable for human consumption Apart frombeing aesthetically displeasing colored water also reducesphotosynthetic action by preventing penetration of light[2] Some dyes andor their metabolites have carcinogenicmutagenic and teratogenic effects on aquatic life and humanbeings [2 4] As adsorption is one of the most efficienttechniques available for dye removal [5] and the commercialadsorbents like activated carbon are expensive [6] searchis carried by several researchers for identifying low-costadsorbents

is has promptedmany researchers to search for cheapersubstitutes such as shells of bittim [7] wheat shells [1]bagasse y ash [3] rice husk [8] acid treated rice husk[9] water hyacinth roots [10] saw dust [11] dead biomass[12 13] espesia populnea bark [14] Ananas comosus

Activated carbon [15] peel of Cucumis sativus fruit [16]Researchers have produced activated carbon from variouslow-cost materials [17ndash21] in an attempt to reduce the costof carbon production In addition researchers have alsoexplored the possibilities of using unburned carbon [6] Inthe present investigation application of carbon made from alow-cost agricultural waste senescent plant leaf powder foradsorption of methylene blue (MB) was examined

2 Materials andMethods

21 Preparation of Carbon Senescent plant leaves were col-lected from the local gardenMost of these leaves weremainlyof teak (Tectona grandis) and Guava (Psidium guajava) treese collected plant leaves were dried in hot air oven at 100∘Cto complete dryness and then ground in a mixere powderwas lled in self-sealed silica crucibles and heated at 500∘C inamuffle furnace for one hour Carbonized powderwas cooledto room temperature in desiccators and screened using BSS(British Standard Screen) test sieves Particles of mesh sizeminus150 + 200 size (average particle size 90 120583120583m) were collectedand used for further studies In the present investigation

2 Journal of Chemistry

0

5

10

15

20

25

30

35

40

45

0 1 2 3 4 5 6 7 8 9 10

0

1

2

3

4

5

6

7

8

9

F 1 Effect of pH on adsorption of MB onto PLC (agitationspeed = 200RPM 1198621198620 = 100mgdm3 dosage = 2 gdm3 119879119879 = 303Kparticle size = 125 120583120583m)

0

5

10

15

20

25

30

35

40

45

0 20 40 60 80 100 120 140 160 180 200

Time (min)

50

100

150

200

F 2 Effect of Concentration on adsorption of MB onto PLC(agitation speed = 200 RPM dosage = 2 gdm3 119879119879 = 303K particlesize = 125 120583120583m)

T 1 Effect of pH on MB adsorption onto PLC

pH 1198961198962 (gmgminus1 minminus1) 119902119902119898119898119898pre (mg gminus1) 1198771198772

20 00009 2042 093640 00030 4381 099860 00060 3140 099580 00030 3134 099090 00039 1620 0977

the carbon obtained was used as it was without furtheractivation e product was designated as PLC (plant leafcarbon)

22 Preparation of Dye Solution e dyes used in this studywere of commercial grade obtained from a nearby textile

0

5

10

15

20

25

30

35

40

45

50

0 20 40 60 80 100 120 140 160

Time (min)

05

1

15

2

Predicted

F 3 Effect of adsorbent dosage (agitation speed = 200 RPMdye concentration = 100mgdm3 119879119879 = 303K particle size =125 120583120583m)

0

5

10

15

20

25

0 50 100 150 200

Time (min)

Predicted

303 K

313 K

323 K

F 4 Effect of temperature (agitation speed = 200 RPMdosage = 2 gdm3 dye concentration = 100mgdm3 particle size =125 120583120583m)

unit and used without further purication ne gram ofMB was dissolved in double distilled water to prepare stocksolution (1000mgdm3) Stock solution was later diluted torequired concentrations Methylene blue is selected in thisstudy for it is (i) widely used by textile industries (ii) wellknown for its adsorption characteristics and (iii) toxic

23 Batch Adsorption Studies For each run 100mL ofdye solution of desired concentration was taken in 250mLconical asks pH of the solution was adusted by addition

Journal of Chemistry 3

T 2 Effect of concentration adsorbent dosage and solution temperature on adsorption of MB onto PLC

1198621198620 (mgdm3) D (gdm3) T (K) 1198961198962 (g mgminus1 minminus1) 119902119902119890119890pre (mgg) h (mg gminus1 minminus1) 1198771198772

50 20 303 00088 1673 01472 0999100 20 303 00043 2488 01070 0999150 20 303 00036 3297 01187 0999200 20 303 00023 4186 00963 0999100 05 303 00011 5107 00562 0998100 10 303 00015 4455 00668 0998100 15 303 00020 3818 00764 0999100 20 313 00063 2210 01392 0998100 20 323 00099 1799 01781 0999

of 01 HCl or 01 aOH as needed enite quantityof PLC was added to the solution and the mixture was keptin an incubated orbital shaker at 200 RPM Samples weredrawn from the mixture using a ne tip syringe at regulartime intervals for analysis Samples were centrifuged andconcentrations of supernatant solutions were determinedby measuring absorbance at 120582120582max (662 nm) using UV-Visspectrophotometer (Systronics 2201) When the absorbanceexceeded 10 the solution was suitably diluted with doubleddistilled water and concentration of diluted solution wasdetermined

Specic uptake of dye at any time ldquo119905119905rdquo was calculated usingthe following equation

119902119902119905119905 =100764910076491198621198620 minus 11986211986211990511990510076651007665119863119863

mgg (1)

where 119902119902119905119905 = specic uptake (amount of dye adsorbedamountof adsorbent used mgg) at time ldquotrdquo min 119863119863 = amount ofadsorbent used (gdm3) and 1198621198620 and 119862119862119905119905 are aqueous phaseconcentration of MB at time 119905119905 = 0 and 119905119905 = 119905119905min respectively(mgdm3)

24 AdsorptionKinetics Pseudo-second-order kineticmodel[27ndash29] was used to test the kinetics in this work Pseudo-second-order is expressed in linear form as follows

Pseudo-second-order kinetic model

119905119905119902119902119905119905=111989611989621199021199022119890119890+119905119905119902119902119890119890 (2)

where 119902119902119905119905 = dye uptake at time 119905119905 (mgg) 119902119902119890119890 = equilibriumdye uptake at time 119905119905 (mgg) 119905119905-time (min) 1198961198962-pseudo secondorder rate constant (gmgminus1minminus1)

Values of 1198961198962 and 119902119902119890119890 were estimated by linear regression

25 Equilibrium and ermodynamic Analysis Most fre-quently employed isotherm models namely Langmuir [30]and Freundlich [31] were used in this study for equilibriumanalysis

Langmuir isotherm is given by the following expression

119902119902119890119890 = 1199021199021198981198981198701198701198711198711198621198621198901198901 + 119870119870119871119871119862119862119890119890

(3)

where 119862119862119890119890 = equilibrium dye concentration in liquid phase(mgdm3) 119870119870119871119871 = Langmuir adsorption constant (dm3mgminus1)119902119902119898119898 = Langmuir isotherm parameter and maximum dyeadsorbedunit mass of adsorbent (mg gminus1) A dimensionlessseparation factor 119877119877119871119871 expressed as a function of 119870119870119871119871 is oenemployed as indicator of the feasibility of any adsorptionprocess It is dened as 119877119877119871119871 = 1(1 + 1198701198701198711198711198621198620) Adsorptionprocess is considered to be feasible if value of 119877119877119871119871 lies between0 and 1

Freundlich isotherm is given by the following expression

119902119902119890119890 = 1198701198701198651198651198621198621119899119899119890119890 (4)

119870119870119865119865 = Freundlich constant (mg gminus1) (dm3mg)1119899119899 1119899119899 =Freundlich isotherm parameter

Isotherm parameters were estimated by nonlinear regres-sion using chi-square as an error estimate

ermodynamic parameters namely free energyenthalpy and entropy changes of adsorption were estimatedusing Vant Hoff rsquos equation stated as follows [1]

ln119870119870119871119871 = minusΔ1198661198660

119877119877119877119877=Δ1198781198780

119877119877minusΔ1198671198670

119877119877119877119877 (5)

where Δ1198661198660 is free energy of adsorption (Jmolminus1) Δ1198671198670 ischange in enthalpy (Jmolminus1) and Δ1198781198780 is change in entropy(Jmolminus1Kminus1)

3 Results and Discussion

31 Effect of Initial Solution pH One of the variables thatmost inuence the adsorption process is pH us effect ofpH on adsorption of MB on PLC was studied by varying thepH Equilibrium uptakes of PLC at various initial solutionpH are shown in Figure 1 along with corresponding nalpH However earlier reports on adsorption on basic dyeson activated carbon suggest that equilibrium dye uptakeincrease with increasing initial solution pH In the case ofactivated carbon adsorption was due to the electrostaticattraction between the dye molecules and the adsorbent Asthe activated carbon is protonated at low pH adsorption ofcationic dyes is favored by increase in initial solution pHHowever in this paper uptake was low at both high (9)and low (2) pH is suggests that electrostatic forces may

4 Journal of Chemistry

not be solely responsible for the dye adsorption on PLCSince PLC used in this study had not been activated (doesnot contain active sites) this may be possible However thisobservation suggests that more detailed study is requiredEstimated pseudo-second-order kinetic parameters are listedin Table 1 High 1198771198772 value conrms the suitability of pseudo-second-order model to explain the kinetics ofMB adsorptiononto PLC However the remaining studies were conducted atpH 7 to avoid possible operational difficulties involved in theuse of low pH (like 4)

32 Effect of Dye Concentration Effect of concentrationon adsorption of MB onto PLC was studied by varyingconcentration from 50 to 200mgdm3 Second-order kineticparameters are shown in Table 2 It could be noticed thatadsorption rate constant 1198961198962 decreased with increase inconcentration of the dye Meanwhile maximum specicuptake increased with increase in initial concentrationeseobservations were consistent with earlier reports [3 32ndash37]In order to predict the kinetic parameters 1198961198962 in terms of initialdye concentration following models was proposed [38]

1198961198962 =1198861198861119862119862011988611988621198621198620 + 1198861198863

(6)

Regression coefficients (1198861198861 1198861198862 and 1198861198863) and coefficient ofdeterminations (1198771198772) were determined using nonlinear regres-sion Substituting the regression coefficients the followingempirical equation was obtained

1198961198962 =0018711986211986207491198621198620 minus 26983

1198771198772 = 9825 (7)

Comparison of predicted pseudo-second-order kinetics withthe experimental data is shown in Figure 2

33 Effect of Adsorbent Dosage Figure 3 illustrates the effectof adsorbent dosage on adsorption of MB Dye uptake wasfound to decrease with increase adsorbent dosage is wasdue to the fact that at smaller adsorbent dosages fraction ofactive sites saturated with dye increases is was consistentwith previous reports [29] It was evident from this gurethat initial rate of adsorption was much higher when theadsorbent dosage was higher e values of kinetic param-eters along with initial adsorption rate are given in Table 2Initial rate of adsorption is dened as the product of kineticrate constant and square of equilibrium uptake (ℎ = 1198961198962119902119902

2119890119890

mg gminus1minminus1) [29]

34 Effect of Temperature Effect of temperature is shown inFigure 4 Pseudo-second-order model ts the experimentaldata very well and the kinetic parameters are shown in Table2 along with the regression coefficients Uptake decreaseswith increase in temperature while kinetic constant increasewith increase in temperature Temperature dependency ofthe rate constant was exponential and follows Arrheniuslaw [38] A plot of ln 1198961198962 versus 1119879119879 was a straight line(plot not shown here) Activation energy of the process wasdetermined from the slope of the Arrhenius plot It was foundto be 3395 kJmol

0

10

20

30

40

50

60

70

0 50 100 150 200

Lang

Freundlich

F 5 Equilibrium curve for adsorption of MB onto PLC at303K (agitation speed = 200 RPM dosage= 2 gdm3 particle size =125 120583120583m)

T 3 Equilibrium parameters for adsorption of MB onto PLC

Langmuir Freundlich119870119870119871119871 dm

3mg 0205 119870119870119865119865 (mgg) (dm3mg)1119899119899 2036119902119902max mgg 6122 119873119873 4411205941205942 1124 1205941205942 12871198771198772 9433 1198771198772 9229

35 Equilibrium Best tting isotherm model was found byusing least squaremethod and byminimizing nonlinear errorfunction1205941205942 [39ndash41] It was found that Langmuirmodel t thedata well with high 1198771198772 and low chi2 values when comparedto that of Freundlich model e Langmuir and Freundlichisotherm parameters at 303K are given in Table 3 along with1198771198772 and 1205941205942 values [39ndash41] e comparison of experimentaldata with the predicted values at 303K is given in Figure 5Dimensionless parameter 119877119877119871119871 suggests that adsorption of MBonto PLC is a feasible process A comparison of adsorptionpotential of PLC with other adsorbents reported recentlyin the literature is given in Table 4 It could be seen thatadsorption of potential of PLC was low compared to thatof various activated carbons is is expected and logical asthe PLC reported in this study is not activated Howeverthe adsorption potential of PLC was better than that ofmany naturalunmodied alternate adsorbents reported inthe literature

36 ermodynamic Analysis e Langmuir parameter 119870119870119871119871was used to determine the thermodynamic parameter Gibbrsquosfree energy change which is an indicator of feasibility of theadsorption process Meanwhile a plot of ln 119870119870119871119871 versus 1119879119879(gure not shown here) gives other thermodynamic param-eters namely enthalpy and entropy changes of adsorptionprocess ese values are shown in Table 5 Negative values

Journal of Chemistry 5

T 4 Comparison of adsorption capacities of low cost adsorbents

Adsorbent Adsorption potential (mgg) ReferenceGrass waste (GW) 457640 [22]Jackfruit peel (JFP) 285713 [23]Rejected tea (RT) 147ndash156 [24]PLC 6122 Present studyWheat shell 1656ndash2150 [2]Posidonia oceanica (L) bres 556 [25]Pretreated dead Streptomyces rimosus 693ndash986 [26]

T 5 ermodynamics parameters for adsorption of MB ontoPLC

T (K) ΔG (JmoL) ΔH (JmoL) ΔS (Jmol K) 1198771198772

293 minus216500

231464 1531 09957303 minus233236313 minus247481323 minus262706

of Δ119866119866 indicate the feasibility of the process Positive value ofother Δ119867119867 indicates that the process is endothermic PositiveΔ119878119878 indicated increased disorder of the dye molecules on thesolid surface aer adsorption Low value of Δ119867119867 also suggeststhat the adsorptionmay be due to physical binding forceseearlier observation increasing dye uptake with increasingtemperature is also consistent with this nding

4 Conclusion

Adsorption of MB onto carbon derived from plant leaves(PLC) an agro-waste was studied Effects of variables likeinitial solution pH initial dye concentration amount ofadsorbent used and solution temperature were studied inbatch mode Adsorption kinetics was well described bypseudo-second-ordermodel UsingArrhenius equation acti-vation energy of MB adsorption on PLC was estimated to be3335 kJmol Langmuir monolayer adsorption capacity (119902119902119898119898)was determined to be 6122mgg From the thermodynamicparameters it can be concluded that the process was spon-taneous endothermic physisorption From the results of thestudy it could be concluded that PLC can be effectively usedfor the removal of methylene blue from aqueous solutions

References

[1] Y Bulut and H Aydin ldquoA kinetics and thermodynamics studyofmethylene blue adsorption onwheat shellsrdquoDesalination vol194 no 1ndash3 pp 259ndash267 2006

[2] RGong Y Jin J Chen YHu and J Sun ldquoRemoval of basic dyesfromaqueous solution by sorption on phosphoric acidmodiedrice strawrdquoDyes and Pigments vol 73 no 3 pp 332ndash337 2007

[3] V S Mane I D Mall and V C Srivastava ldquoUse of bagassey ash as an adsorbent for the removal of brilliant green dyefrom aqueous solutionrdquo Dyes and Pigments vol 73 no 3 pp269ndash278 2007

[4] N Yeddou and A Bensmaili ldquoKinetic models for the sorptionof dye from aqueous solution by clay-wood sawdust mixturerdquoDesalination vol 185 no 1ndash3 pp 499ndash508 2005

[5] P Nigam I M Banat D Singh and R Marchant ldquoMicrobialprocess for the decolorization of textile effluent containing azodiazo and reactive dyesrdquo Process Biochemistry vol 31 no 5 pp435ndash442 1996

[6] S Wang and H Li ldquoKinetic modelling and mechanism of dyeadsorption on unburned carbonrdquo Dyes and Pigments vol 72no 3 pp 308ndash314 2007

[7] H Aydin and G Baysal ldquoAdsorption of acid dyes in aqueoussolutions by shells of bittim (Pistacia khinjuk Stocks)rdquo Desali-nation vol 196 no 1ndash3 pp 248ndash259 2006

[8] M C Shih ldquoKinetics of the batch adsorption of methyleneblue from aqueous solutions onto rice husk effect of acid-modied process and dye concentrationrdquo Desalination andWater Treatment vol 37 no 1ndash3 pp 200ndash214 2012

[9] V Ponnusami V Krithika R Madhuram and S N SrivastavaldquoBiosorption of reactive dye using acid-treated rice huskfactorial design analysisrdquo Journal of Hazardous Materials vol142 no 1-2 pp 397ndash403 2007

[10] K S Low C K Lee and K K Tan ldquoBiosorption of basic dyesby water hyacinth rootsrdquo Bioresource Technology vol 52 no 1pp 79ndash83 1995

[11] V K Garg R Gupta A B Yadav and R Kumar ldquoDye removalfrom aqueous solution by adsorption on treated sawdustrdquoBioresource Technology vol 89 no 2 pp 121ndash124 2003

[12] M Bustard G McMullan and A P McHale ldquoBiosorption oftextile dyes by biomass derived fromKluyveromycesmarxianusIMB3rdquo Bioprocess Engineering vol 19 no 6 pp 427ndash430 1998

[13] T V N Padmesh K Vijayaraghavan G Sekaran andM VelanldquoBiosorption ofAcid Blue 15 using freshwatermacroalgaAzollaliculoides batch and column studiesrdquo Dyes and Pigments vol71 no 2 pp 77ndash82 2006

[14] R Prabakaran and S Arivoli ldquoermodynamic and isothermanalysis on the removal of malachite green dye using thespesiapopulnea barkrdquo E-Journal of Chemistry vol 9 no 4 pp2575ndash2588 2012

[15] R Parimalam V Raj and P Sivakumar ldquoRemoval of acidgreen 25 from aqueous solution by adsorptionrdquo E-Journal ofChemistry vol 9 no 4 pp 1683ndash1698 2012

[16] T Smitha S irumalisamy and S Manonmani ldquoEquilibriumand kinetics study of adsorption of crystal violet onto the peelof cucumis sativa fruit from aqueous solutionrdquo E-Journal ofChemistry vol 9 pp 1091ndash1101 2012

[17] Y Guo J Zhao H Zhang et al ldquoUse of rice husk-based porouscarbon for adsorption of RhodamineB fromaqueous solutionsrdquoDyes and Pigments vol 66 no 2 pp 123ndash128 2005

6 Journal of Chemistry

[18] A Jumasiah T G Chuah J Gimbon T S Y Choong andI Azni ldquoAdsorption of basic dye onto palm kernel shellactivated carbon sorption equilibrium and kinetics studiesrdquoDesalination vol 186 no 1ndash3 pp 57ndash64 2005

[19] N Kannan and M M Sundaram ldquoKinetics and mechanism ofremoval ofmethylene blue by adsorption on various carbonsmdashacomparative studyrdquoDyes and Pigments vol 51 no 1 pp 25ndash402001

[20] P K Malik ldquoUse of activated carbons prepared from sawdustand rice-husk for adsoprtion of acid dyes a case study of acidyellow 36rdquoDyes and Pigments vol 56 no 3 pp 239ndash249 2003

[21] P Janoš P Michaacutelek and L Turek ldquoSorption of ionic dyes ontountreated low-rank coalmdashoxihumolite a kinetic studyrdquo Dyesand Pigments vol 74 no 2 pp 363ndash370 2007

[22] B H Hameed ldquoGrass waste a novel sorbent for the removalof basic dye from aqueous solutionrdquo Journal of HazardousMaterials vol 166 no 1 pp 233ndash238 2009

[23] B H Hameed ldquoRemoval of cationic dye from aqueous solutionusing jackfruit peel as non-conventional low-cost adsorbentrdquoJournal of Hazardous Materials vol 162 no 1 pp 344ndash3502009

[24] N Nasuha B H Hameed and A T M Din ldquoRejected tea as apotential low-cost adsorbent for the removal ofmethylene bluerdquoJournal of Hazardous Materials vol 175 no 1ndash3 pp 126ndash1322010

[25] N Nasuha B H Hameed and A T M Din ldquoRejected tea as apotential low-cost adsorbent for the removal ofmethylene bluerdquoJournal of Hazardous Materials vol 175 no 1ndash3 pp 126ndash1322010

[26] M C Ncibi B Mahjoub and M Seffen ldquoKinetic and equi-librium studies of methylene blue biosorption by Posidoniaoceanica (L) bresrdquo Journal of Hazardous Materials vol 139no 2 pp 280ndash285 2007

[27] Y S Ho and G McKay ldquoPseudo-second order model forsorption processesrdquo Process Biochemistry vol 34 no 5 pp451ndash465 1999

[28] Y S Ho and G McKay ldquoe kinetics of sorption of divalentmetal ions onto sphagnum moss peatrdquoWater Research vol 34no 3 pp 735ndash742 2000

[29] Y S Ho and G McKay ldquoA kinetic study of dye sorption bybiosorbent waste product pithrdquo Resources Conservation andRecycling vol 25 no 3-4 pp 171ndash193 1999

[30] I Langmuir ldquoe constitution and fundamental properties ofsolids and liquids Part I Solidsrdquo e Journal of the AmericanChemical Society vol 38 no 2 pp 2221ndash2295 1916

[31] H M F Freundlich ldquoUber die adsorption in losungenrdquoZeitschri fuumlr Physikalische Chemie vol 57 pp 385ndash470 1906

[32] V Ponnusami S Vikram and S N Srivastava ldquoGuava (Psidiumguajava) leaf powder novel adsorbent for removal ofmethyleneblue from aqueous solutionsrdquo Journal of Hazardous Materialsvol 152 no 1 pp 276ndash286 2008

[33] V Ponnusami V Gunasekar and S N Srivastava ldquoKinetics ofmethylene blue removal from aqueous solution using gulmo-har (Delonix regia) plant leaf powder multivariate regressionanalysisrdquo Journal of Hazardous Materials vol 169 no 1ndash3 pp119ndash127 2009

[34] B HHameed ldquoEquilibrium and kinetic studies ofmethyl violetsorption by agricultural wasterdquo Journal of Hazardous Materialsvol 154 no 1ndash3 pp 204ndash212 2008

[35] B H Hameed A L Ahmad and K N A Latiff ldquoAdsorption ofbasic dye (methylene blue) onto activated carbon prepared from

rattan sawdustrdquo Dyes and Pigments vol 75 no 1 pp 143ndash1492007

[36] B H Hameed and F B M Daud ldquoAdsorption studies of basicdye on activated carbon derived from agricultural waste heveabrasiliensis seed coatrdquo Chemical Engineering Journal vol 139no 1 pp 48ndash55 2008

[37] M I El-Khaiary ldquoKinetics and mechanism of adsorption ofmethylene blue from aqueous solution by nitric-acid treatedwater-hyacinthrdquo Journal of Hazardous Materials vol 147 no1-2 pp 28ndash36 2007

[38] Y S Ho and G McKay ldquoSorption of dye from aqueous solutionby peatrdquo Chemical Engineering Journal vol 70 no 2 pp115ndash124 1998

[39] Y SHo ldquoSelection of optimum sorption isothermrdquoCarbon vol42 no 10 pp 2115ndash2116 2004

[40] G Crini H N Peindy F Gimbert and C Robert ldquoRemoval ofCI Basic Green 4 (Malachite Green) from aqueous solutionsby adsorption using cyclodextrin-based adsorbent kinetic andequilibrium studiesrdquo Searation and Purication Technologyvol 53 no 1 pp 97ndash110 2007

[41] Y SHoWTChiu andCCWang ldquoRegression analysis for thesorption isotherms of basic dyes on sugarcane dustrdquo BioresourceTechnology vol 96 no 11 pp 1285ndash1291 2005

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Journal of

Spectroscopy

2 Journal of Chemistry

0

5

10

15

20

25

30

35

40

45

0 1 2 3 4 5 6 7 8 9 10

0

1

2

3

4

5

6

7

8

9

F 1 Effect of pH on adsorption of MB onto PLC (agitationspeed = 200RPM 1198621198620 = 100mgdm3 dosage = 2 gdm3 119879119879 = 303Kparticle size = 125 120583120583m)

0

5

10

15

20

25

30

35

40

45

0 20 40 60 80 100 120 140 160 180 200

Time (min)

50

100

150

200

F 2 Effect of Concentration on adsorption of MB onto PLC(agitation speed = 200 RPM dosage = 2 gdm3 119879119879 = 303K particlesize = 125 120583120583m)

T 1 Effect of pH on MB adsorption onto PLC

pH 1198961198962 (gmgminus1 minminus1) 119902119902119898119898119898pre (mg gminus1) 1198771198772

20 00009 2042 093640 00030 4381 099860 00060 3140 099580 00030 3134 099090 00039 1620 0977

the carbon obtained was used as it was without furtheractivation e product was designated as PLC (plant leafcarbon)

22 Preparation of Dye Solution e dyes used in this studywere of commercial grade obtained from a nearby textile

0

5

10

15

20

25

30

35

40

45

50

0 20 40 60 80 100 120 140 160

Time (min)

05

1

15

2

Predicted

F 3 Effect of adsorbent dosage (agitation speed = 200 RPMdye concentration = 100mgdm3 119879119879 = 303K particle size =125 120583120583m)

0

5

10

15

20

25

0 50 100 150 200

Time (min)

Predicted

303 K

313 K

323 K

F 4 Effect of temperature (agitation speed = 200 RPMdosage = 2 gdm3 dye concentration = 100mgdm3 particle size =125 120583120583m)

unit and used without further purication ne gram ofMB was dissolved in double distilled water to prepare stocksolution (1000mgdm3) Stock solution was later diluted torequired concentrations Methylene blue is selected in thisstudy for it is (i) widely used by textile industries (ii) wellknown for its adsorption characteristics and (iii) toxic

23 Batch Adsorption Studies For each run 100mL ofdye solution of desired concentration was taken in 250mLconical asks pH of the solution was adusted by addition

Journal of Chemistry 3

T 2 Effect of concentration adsorbent dosage and solution temperature on adsorption of MB onto PLC

1198621198620 (mgdm3) D (gdm3) T (K) 1198961198962 (g mgminus1 minminus1) 119902119902119890119890pre (mgg) h (mg gminus1 minminus1) 1198771198772

50 20 303 00088 1673 01472 0999100 20 303 00043 2488 01070 0999150 20 303 00036 3297 01187 0999200 20 303 00023 4186 00963 0999100 05 303 00011 5107 00562 0998100 10 303 00015 4455 00668 0998100 15 303 00020 3818 00764 0999100 20 313 00063 2210 01392 0998100 20 323 00099 1799 01781 0999

of 01 HCl or 01 aOH as needed enite quantityof PLC was added to the solution and the mixture was keptin an incubated orbital shaker at 200 RPM Samples weredrawn from the mixture using a ne tip syringe at regulartime intervals for analysis Samples were centrifuged andconcentrations of supernatant solutions were determinedby measuring absorbance at 120582120582max (662 nm) using UV-Visspectrophotometer (Systronics 2201) When the absorbanceexceeded 10 the solution was suitably diluted with doubleddistilled water and concentration of diluted solution wasdetermined

Specic uptake of dye at any time ldquo119905119905rdquo was calculated usingthe following equation

119902119902119905119905 =100764910076491198621198620 minus 11986211986211990511990510076651007665119863119863

mgg (1)

where 119902119902119905119905 = specic uptake (amount of dye adsorbedamountof adsorbent used mgg) at time ldquotrdquo min 119863119863 = amount ofadsorbent used (gdm3) and 1198621198620 and 119862119862119905119905 are aqueous phaseconcentration of MB at time 119905119905 = 0 and 119905119905 = 119905119905min respectively(mgdm3)

24 AdsorptionKinetics Pseudo-second-order kineticmodel[27ndash29] was used to test the kinetics in this work Pseudo-second-order is expressed in linear form as follows

Pseudo-second-order kinetic model

119905119905119902119902119905119905=111989611989621199021199022119890119890+119905119905119902119902119890119890 (2)

where 119902119902119905119905 = dye uptake at time 119905119905 (mgg) 119902119902119890119890 = equilibriumdye uptake at time 119905119905 (mgg) 119905119905-time (min) 1198961198962-pseudo secondorder rate constant (gmgminus1minminus1)

Values of 1198961198962 and 119902119902119890119890 were estimated by linear regression

25 Equilibrium and ermodynamic Analysis Most fre-quently employed isotherm models namely Langmuir [30]and Freundlich [31] were used in this study for equilibriumanalysis

Langmuir isotherm is given by the following expression

119902119902119890119890 = 1199021199021198981198981198701198701198711198711198621198621198901198901 + 119870119870119871119871119862119862119890119890

(3)

where 119862119862119890119890 = equilibrium dye concentration in liquid phase(mgdm3) 119870119870119871119871 = Langmuir adsorption constant (dm3mgminus1)119902119902119898119898 = Langmuir isotherm parameter and maximum dyeadsorbedunit mass of adsorbent (mg gminus1) A dimensionlessseparation factor 119877119877119871119871 expressed as a function of 119870119870119871119871 is oenemployed as indicator of the feasibility of any adsorptionprocess It is dened as 119877119877119871119871 = 1(1 + 1198701198701198711198711198621198620) Adsorptionprocess is considered to be feasible if value of 119877119877119871119871 lies between0 and 1

Freundlich isotherm is given by the following expression

119902119902119890119890 = 1198701198701198651198651198621198621119899119899119890119890 (4)

119870119870119865119865 = Freundlich constant (mg gminus1) (dm3mg)1119899119899 1119899119899 =Freundlich isotherm parameter

Isotherm parameters were estimated by nonlinear regres-sion using chi-square as an error estimate

ermodynamic parameters namely free energyenthalpy and entropy changes of adsorption were estimatedusing Vant Hoff rsquos equation stated as follows [1]

ln119870119870119871119871 = minusΔ1198661198660

119877119877119877119877=Δ1198781198780

119877119877minusΔ1198671198670

119877119877119877119877 (5)

where Δ1198661198660 is free energy of adsorption (Jmolminus1) Δ1198671198670 ischange in enthalpy (Jmolminus1) and Δ1198781198780 is change in entropy(Jmolminus1Kminus1)

3 Results and Discussion

31 Effect of Initial Solution pH One of the variables thatmost inuence the adsorption process is pH us effect ofpH on adsorption of MB on PLC was studied by varying thepH Equilibrium uptakes of PLC at various initial solutionpH are shown in Figure 1 along with corresponding nalpH However earlier reports on adsorption on basic dyeson activated carbon suggest that equilibrium dye uptakeincrease with increasing initial solution pH In the case ofactivated carbon adsorption was due to the electrostaticattraction between the dye molecules and the adsorbent Asthe activated carbon is protonated at low pH adsorption ofcationic dyes is favored by increase in initial solution pHHowever in this paper uptake was low at both high (9)and low (2) pH is suggests that electrostatic forces may

4 Journal of Chemistry

not be solely responsible for the dye adsorption on PLCSince PLC used in this study had not been activated (doesnot contain active sites) this may be possible However thisobservation suggests that more detailed study is requiredEstimated pseudo-second-order kinetic parameters are listedin Table 1 High 1198771198772 value conrms the suitability of pseudo-second-order model to explain the kinetics ofMB adsorptiononto PLC However the remaining studies were conducted atpH 7 to avoid possible operational difficulties involved in theuse of low pH (like 4)

32 Effect of Dye Concentration Effect of concentrationon adsorption of MB onto PLC was studied by varyingconcentration from 50 to 200mgdm3 Second-order kineticparameters are shown in Table 2 It could be noticed thatadsorption rate constant 1198961198962 decreased with increase inconcentration of the dye Meanwhile maximum specicuptake increased with increase in initial concentrationeseobservations were consistent with earlier reports [3 32ndash37]In order to predict the kinetic parameters 1198961198962 in terms of initialdye concentration following models was proposed [38]

1198961198962 =1198861198861119862119862011988611988621198621198620 + 1198861198863

(6)

Regression coefficients (1198861198861 1198861198862 and 1198861198863) and coefficient ofdeterminations (1198771198772) were determined using nonlinear regres-sion Substituting the regression coefficients the followingempirical equation was obtained

1198961198962 =0018711986211986207491198621198620 minus 26983

1198771198772 = 9825 (7)

Comparison of predicted pseudo-second-order kinetics withthe experimental data is shown in Figure 2

33 Effect of Adsorbent Dosage Figure 3 illustrates the effectof adsorbent dosage on adsorption of MB Dye uptake wasfound to decrease with increase adsorbent dosage is wasdue to the fact that at smaller adsorbent dosages fraction ofactive sites saturated with dye increases is was consistentwith previous reports [29] It was evident from this gurethat initial rate of adsorption was much higher when theadsorbent dosage was higher e values of kinetic param-eters along with initial adsorption rate are given in Table 2Initial rate of adsorption is dened as the product of kineticrate constant and square of equilibrium uptake (ℎ = 1198961198962119902119902

2119890119890

mg gminus1minminus1) [29]

34 Effect of Temperature Effect of temperature is shown inFigure 4 Pseudo-second-order model ts the experimentaldata very well and the kinetic parameters are shown in Table2 along with the regression coefficients Uptake decreaseswith increase in temperature while kinetic constant increasewith increase in temperature Temperature dependency ofthe rate constant was exponential and follows Arrheniuslaw [38] A plot of ln 1198961198962 versus 1119879119879 was a straight line(plot not shown here) Activation energy of the process wasdetermined from the slope of the Arrhenius plot It was foundto be 3395 kJmol

0

10

20

30

40

50

60

70

0 50 100 150 200

Lang

Freundlich

F 5 Equilibrium curve for adsorption of MB onto PLC at303K (agitation speed = 200 RPM dosage= 2 gdm3 particle size =125 120583120583m)

T 3 Equilibrium parameters for adsorption of MB onto PLC

Langmuir Freundlich119870119870119871119871 dm

3mg 0205 119870119870119865119865 (mgg) (dm3mg)1119899119899 2036119902119902max mgg 6122 119873119873 4411205941205942 1124 1205941205942 12871198771198772 9433 1198771198772 9229

35 Equilibrium Best tting isotherm model was found byusing least squaremethod and byminimizing nonlinear errorfunction1205941205942 [39ndash41] It was found that Langmuirmodel t thedata well with high 1198771198772 and low chi2 values when comparedto that of Freundlich model e Langmuir and Freundlichisotherm parameters at 303K are given in Table 3 along with1198771198772 and 1205941205942 values [39ndash41] e comparison of experimentaldata with the predicted values at 303K is given in Figure 5Dimensionless parameter 119877119877119871119871 suggests that adsorption of MBonto PLC is a feasible process A comparison of adsorptionpotential of PLC with other adsorbents reported recentlyin the literature is given in Table 4 It could be seen thatadsorption of potential of PLC was low compared to thatof various activated carbons is is expected and logical asthe PLC reported in this study is not activated Howeverthe adsorption potential of PLC was better than that ofmany naturalunmodied alternate adsorbents reported inthe literature

36 ermodynamic Analysis e Langmuir parameter 119870119870119871119871was used to determine the thermodynamic parameter Gibbrsquosfree energy change which is an indicator of feasibility of theadsorption process Meanwhile a plot of ln 119870119870119871119871 versus 1119879119879(gure not shown here) gives other thermodynamic param-eters namely enthalpy and entropy changes of adsorptionprocess ese values are shown in Table 5 Negative values

Journal of Chemistry 5

T 4 Comparison of adsorption capacities of low cost adsorbents

Adsorbent Adsorption potential (mgg) ReferenceGrass waste (GW) 457640 [22]Jackfruit peel (JFP) 285713 [23]Rejected tea (RT) 147ndash156 [24]PLC 6122 Present studyWheat shell 1656ndash2150 [2]Posidonia oceanica (L) bres 556 [25]Pretreated dead Streptomyces rimosus 693ndash986 [26]

T 5 ermodynamics parameters for adsorption of MB ontoPLC

T (K) ΔG (JmoL) ΔH (JmoL) ΔS (Jmol K) 1198771198772

293 minus216500

231464 1531 09957303 minus233236313 minus247481323 minus262706

of Δ119866119866 indicate the feasibility of the process Positive value ofother Δ119867119867 indicates that the process is endothermic PositiveΔ119878119878 indicated increased disorder of the dye molecules on thesolid surface aer adsorption Low value of Δ119867119867 also suggeststhat the adsorptionmay be due to physical binding forceseearlier observation increasing dye uptake with increasingtemperature is also consistent with this nding

4 Conclusion

Adsorption of MB onto carbon derived from plant leaves(PLC) an agro-waste was studied Effects of variables likeinitial solution pH initial dye concentration amount ofadsorbent used and solution temperature were studied inbatch mode Adsorption kinetics was well described bypseudo-second-ordermodel UsingArrhenius equation acti-vation energy of MB adsorption on PLC was estimated to be3335 kJmol Langmuir monolayer adsorption capacity (119902119902119898119898)was determined to be 6122mgg From the thermodynamicparameters it can be concluded that the process was spon-taneous endothermic physisorption From the results of thestudy it could be concluded that PLC can be effectively usedfor the removal of methylene blue from aqueous solutions

References

[1] Y Bulut and H Aydin ldquoA kinetics and thermodynamics studyofmethylene blue adsorption onwheat shellsrdquoDesalination vol194 no 1ndash3 pp 259ndash267 2006

[2] RGong Y Jin J Chen YHu and J Sun ldquoRemoval of basic dyesfromaqueous solution by sorption on phosphoric acidmodiedrice strawrdquoDyes and Pigments vol 73 no 3 pp 332ndash337 2007

[3] V S Mane I D Mall and V C Srivastava ldquoUse of bagassey ash as an adsorbent for the removal of brilliant green dyefrom aqueous solutionrdquo Dyes and Pigments vol 73 no 3 pp269ndash278 2007

[4] N Yeddou and A Bensmaili ldquoKinetic models for the sorptionof dye from aqueous solution by clay-wood sawdust mixturerdquoDesalination vol 185 no 1ndash3 pp 499ndash508 2005

[5] P Nigam I M Banat D Singh and R Marchant ldquoMicrobialprocess for the decolorization of textile effluent containing azodiazo and reactive dyesrdquo Process Biochemistry vol 31 no 5 pp435ndash442 1996

[6] S Wang and H Li ldquoKinetic modelling and mechanism of dyeadsorption on unburned carbonrdquo Dyes and Pigments vol 72no 3 pp 308ndash314 2007

[7] H Aydin and G Baysal ldquoAdsorption of acid dyes in aqueoussolutions by shells of bittim (Pistacia khinjuk Stocks)rdquo Desali-nation vol 196 no 1ndash3 pp 248ndash259 2006

[8] M C Shih ldquoKinetics of the batch adsorption of methyleneblue from aqueous solutions onto rice husk effect of acid-modied process and dye concentrationrdquo Desalination andWater Treatment vol 37 no 1ndash3 pp 200ndash214 2012

[9] V Ponnusami V Krithika R Madhuram and S N SrivastavaldquoBiosorption of reactive dye using acid-treated rice huskfactorial design analysisrdquo Journal of Hazardous Materials vol142 no 1-2 pp 397ndash403 2007

[10] K S Low C K Lee and K K Tan ldquoBiosorption of basic dyesby water hyacinth rootsrdquo Bioresource Technology vol 52 no 1pp 79ndash83 1995

[11] V K Garg R Gupta A B Yadav and R Kumar ldquoDye removalfrom aqueous solution by adsorption on treated sawdustrdquoBioresource Technology vol 89 no 2 pp 121ndash124 2003

[12] M Bustard G McMullan and A P McHale ldquoBiosorption oftextile dyes by biomass derived fromKluyveromycesmarxianusIMB3rdquo Bioprocess Engineering vol 19 no 6 pp 427ndash430 1998

[13] T V N Padmesh K Vijayaraghavan G Sekaran andM VelanldquoBiosorption ofAcid Blue 15 using freshwatermacroalgaAzollaliculoides batch and column studiesrdquo Dyes and Pigments vol71 no 2 pp 77ndash82 2006

[14] R Prabakaran and S Arivoli ldquoermodynamic and isothermanalysis on the removal of malachite green dye using thespesiapopulnea barkrdquo E-Journal of Chemistry vol 9 no 4 pp2575ndash2588 2012

[15] R Parimalam V Raj and P Sivakumar ldquoRemoval of acidgreen 25 from aqueous solution by adsorptionrdquo E-Journal ofChemistry vol 9 no 4 pp 1683ndash1698 2012

[16] T Smitha S irumalisamy and S Manonmani ldquoEquilibriumand kinetics study of adsorption of crystal violet onto the peelof cucumis sativa fruit from aqueous solutionrdquo E-Journal ofChemistry vol 9 pp 1091ndash1101 2012

[17] Y Guo J Zhao H Zhang et al ldquoUse of rice husk-based porouscarbon for adsorption of RhodamineB fromaqueous solutionsrdquoDyes and Pigments vol 66 no 2 pp 123ndash128 2005

6 Journal of Chemistry

[18] A Jumasiah T G Chuah J Gimbon T S Y Choong andI Azni ldquoAdsorption of basic dye onto palm kernel shellactivated carbon sorption equilibrium and kinetics studiesrdquoDesalination vol 186 no 1ndash3 pp 57ndash64 2005

[19] N Kannan and M M Sundaram ldquoKinetics and mechanism ofremoval ofmethylene blue by adsorption on various carbonsmdashacomparative studyrdquoDyes and Pigments vol 51 no 1 pp 25ndash402001

[20] P K Malik ldquoUse of activated carbons prepared from sawdustand rice-husk for adsoprtion of acid dyes a case study of acidyellow 36rdquoDyes and Pigments vol 56 no 3 pp 239ndash249 2003

[21] P Janoš P Michaacutelek and L Turek ldquoSorption of ionic dyes ontountreated low-rank coalmdashoxihumolite a kinetic studyrdquo Dyesand Pigments vol 74 no 2 pp 363ndash370 2007

[22] B H Hameed ldquoGrass waste a novel sorbent for the removalof basic dye from aqueous solutionrdquo Journal of HazardousMaterials vol 166 no 1 pp 233ndash238 2009

[23] B H Hameed ldquoRemoval of cationic dye from aqueous solutionusing jackfruit peel as non-conventional low-cost adsorbentrdquoJournal of Hazardous Materials vol 162 no 1 pp 344ndash3502009

[24] N Nasuha B H Hameed and A T M Din ldquoRejected tea as apotential low-cost adsorbent for the removal ofmethylene bluerdquoJournal of Hazardous Materials vol 175 no 1ndash3 pp 126ndash1322010

[25] N Nasuha B H Hameed and A T M Din ldquoRejected tea as apotential low-cost adsorbent for the removal ofmethylene bluerdquoJournal of Hazardous Materials vol 175 no 1ndash3 pp 126ndash1322010

[26] M C Ncibi B Mahjoub and M Seffen ldquoKinetic and equi-librium studies of methylene blue biosorption by Posidoniaoceanica (L) bresrdquo Journal of Hazardous Materials vol 139no 2 pp 280ndash285 2007

[27] Y S Ho and G McKay ldquoPseudo-second order model forsorption processesrdquo Process Biochemistry vol 34 no 5 pp451ndash465 1999

[28] Y S Ho and G McKay ldquoe kinetics of sorption of divalentmetal ions onto sphagnum moss peatrdquoWater Research vol 34no 3 pp 735ndash742 2000

[29] Y S Ho and G McKay ldquoA kinetic study of dye sorption bybiosorbent waste product pithrdquo Resources Conservation andRecycling vol 25 no 3-4 pp 171ndash193 1999

[30] I Langmuir ldquoe constitution and fundamental properties ofsolids and liquids Part I Solidsrdquo e Journal of the AmericanChemical Society vol 38 no 2 pp 2221ndash2295 1916

[31] H M F Freundlich ldquoUber die adsorption in losungenrdquoZeitschri fuumlr Physikalische Chemie vol 57 pp 385ndash470 1906

[32] V Ponnusami S Vikram and S N Srivastava ldquoGuava (Psidiumguajava) leaf powder novel adsorbent for removal ofmethyleneblue from aqueous solutionsrdquo Journal of Hazardous Materialsvol 152 no 1 pp 276ndash286 2008

[33] V Ponnusami V Gunasekar and S N Srivastava ldquoKinetics ofmethylene blue removal from aqueous solution using gulmo-har (Delonix regia) plant leaf powder multivariate regressionanalysisrdquo Journal of Hazardous Materials vol 169 no 1ndash3 pp119ndash127 2009

[34] B HHameed ldquoEquilibrium and kinetic studies ofmethyl violetsorption by agricultural wasterdquo Journal of Hazardous Materialsvol 154 no 1ndash3 pp 204ndash212 2008

[35] B H Hameed A L Ahmad and K N A Latiff ldquoAdsorption ofbasic dye (methylene blue) onto activated carbon prepared from

rattan sawdustrdquo Dyes and Pigments vol 75 no 1 pp 143ndash1492007

[36] B H Hameed and F B M Daud ldquoAdsorption studies of basicdye on activated carbon derived from agricultural waste heveabrasiliensis seed coatrdquo Chemical Engineering Journal vol 139no 1 pp 48ndash55 2008

[37] M I El-Khaiary ldquoKinetics and mechanism of adsorption ofmethylene blue from aqueous solution by nitric-acid treatedwater-hyacinthrdquo Journal of Hazardous Materials vol 147 no1-2 pp 28ndash36 2007

[38] Y S Ho and G McKay ldquoSorption of dye from aqueous solutionby peatrdquo Chemical Engineering Journal vol 70 no 2 pp115ndash124 1998

[39] Y SHo ldquoSelection of optimum sorption isothermrdquoCarbon vol42 no 10 pp 2115ndash2116 2004

[40] G Crini H N Peindy F Gimbert and C Robert ldquoRemoval ofCI Basic Green 4 (Malachite Green) from aqueous solutionsby adsorption using cyclodextrin-based adsorbent kinetic andequilibrium studiesrdquo Searation and Purication Technologyvol 53 no 1 pp 97ndash110 2007

[41] Y SHoWTChiu andCCWang ldquoRegression analysis for thesorption isotherms of basic dyes on sugarcane dustrdquo BioresourceTechnology vol 96 no 11 pp 1285ndash1291 2005

Submit your manuscripts athttpwwwhindawicom

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Carbohydrate Chemistry

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom

International Journal of

Analytical ChemistryVolume 2013

ISRN Chromatography

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawi Publishing Corporation httpwwwhindawicom Volume 2013

The Scientific World Journal

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

CatalystsJournal of

ISRN Analytical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Advances in

Physical Chemistry

ISRN Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

ISRN Inorganic Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Journal of

Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2013

ISRN Organic Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Journal of

Spectroscopy

Journal of Chemistry 3

T 2 Effect of concentration adsorbent dosage and solution temperature on adsorption of MB onto PLC

1198621198620 (mgdm3) D (gdm3) T (K) 1198961198962 (g mgminus1 minminus1) 119902119902119890119890pre (mgg) h (mg gminus1 minminus1) 1198771198772

50 20 303 00088 1673 01472 0999100 20 303 00043 2488 01070 0999150 20 303 00036 3297 01187 0999200 20 303 00023 4186 00963 0999100 05 303 00011 5107 00562 0998100 10 303 00015 4455 00668 0998100 15 303 00020 3818 00764 0999100 20 313 00063 2210 01392 0998100 20 323 00099 1799 01781 0999

of 01 HCl or 01 aOH as needed enite quantityof PLC was added to the solution and the mixture was keptin an incubated orbital shaker at 200 RPM Samples weredrawn from the mixture using a ne tip syringe at regulartime intervals for analysis Samples were centrifuged andconcentrations of supernatant solutions were determinedby measuring absorbance at 120582120582max (662 nm) using UV-Visspectrophotometer (Systronics 2201) When the absorbanceexceeded 10 the solution was suitably diluted with doubleddistilled water and concentration of diluted solution wasdetermined

Specic uptake of dye at any time ldquo119905119905rdquo was calculated usingthe following equation

119902119902119905119905 =100764910076491198621198620 minus 11986211986211990511990510076651007665119863119863

mgg (1)

where 119902119902119905119905 = specic uptake (amount of dye adsorbedamountof adsorbent used mgg) at time ldquotrdquo min 119863119863 = amount ofadsorbent used (gdm3) and 1198621198620 and 119862119862119905119905 are aqueous phaseconcentration of MB at time 119905119905 = 0 and 119905119905 = 119905119905min respectively(mgdm3)

24 AdsorptionKinetics Pseudo-second-order kineticmodel[27ndash29] was used to test the kinetics in this work Pseudo-second-order is expressed in linear form as follows

Pseudo-second-order kinetic model

119905119905119902119902119905119905=111989611989621199021199022119890119890+119905119905119902119902119890119890 (2)

where 119902119902119905119905 = dye uptake at time 119905119905 (mgg) 119902119902119890119890 = equilibriumdye uptake at time 119905119905 (mgg) 119905119905-time (min) 1198961198962-pseudo secondorder rate constant (gmgminus1minminus1)

Values of 1198961198962 and 119902119902119890119890 were estimated by linear regression

25 Equilibrium and ermodynamic Analysis Most fre-quently employed isotherm models namely Langmuir [30]and Freundlich [31] were used in this study for equilibriumanalysis

Langmuir isotherm is given by the following expression

119902119902119890119890 = 1199021199021198981198981198701198701198711198711198621198621198901198901 + 119870119870119871119871119862119862119890119890

(3)

where 119862119862119890119890 = equilibrium dye concentration in liquid phase(mgdm3) 119870119870119871119871 = Langmuir adsorption constant (dm3mgminus1)119902119902119898119898 = Langmuir isotherm parameter and maximum dyeadsorbedunit mass of adsorbent (mg gminus1) A dimensionlessseparation factor 119877119877119871119871 expressed as a function of 119870119870119871119871 is oenemployed as indicator of the feasibility of any adsorptionprocess It is dened as 119877119877119871119871 = 1(1 + 1198701198701198711198711198621198620) Adsorptionprocess is considered to be feasible if value of 119877119877119871119871 lies between0 and 1

Freundlich isotherm is given by the following expression

119902119902119890119890 = 1198701198701198651198651198621198621119899119899119890119890 (4)

119870119870119865119865 = Freundlich constant (mg gminus1) (dm3mg)1119899119899 1119899119899 =Freundlich isotherm parameter

Isotherm parameters were estimated by nonlinear regres-sion using chi-square as an error estimate

ermodynamic parameters namely free energyenthalpy and entropy changes of adsorption were estimatedusing Vant Hoff rsquos equation stated as follows [1]

ln119870119870119871119871 = minusΔ1198661198660

119877119877119877119877=Δ1198781198780

119877119877minusΔ1198671198670

119877119877119877119877 (5)

where Δ1198661198660 is free energy of adsorption (Jmolminus1) Δ1198671198670 ischange in enthalpy (Jmolminus1) and Δ1198781198780 is change in entropy(Jmolminus1Kminus1)

3 Results and Discussion

31 Effect of Initial Solution pH One of the variables thatmost inuence the adsorption process is pH us effect ofpH on adsorption of MB on PLC was studied by varying thepH Equilibrium uptakes of PLC at various initial solutionpH are shown in Figure 1 along with corresponding nalpH However earlier reports on adsorption on basic dyeson activated carbon suggest that equilibrium dye uptakeincrease with increasing initial solution pH In the case ofactivated carbon adsorption was due to the electrostaticattraction between the dye molecules and the adsorbent Asthe activated carbon is protonated at low pH adsorption ofcationic dyes is favored by increase in initial solution pHHowever in this paper uptake was low at both high (9)and low (2) pH is suggests that electrostatic forces may

4 Journal of Chemistry

not be solely responsible for the dye adsorption on PLCSince PLC used in this study had not been activated (doesnot contain active sites) this may be possible However thisobservation suggests that more detailed study is requiredEstimated pseudo-second-order kinetic parameters are listedin Table 1 High 1198771198772 value conrms the suitability of pseudo-second-order model to explain the kinetics ofMB adsorptiononto PLC However the remaining studies were conducted atpH 7 to avoid possible operational difficulties involved in theuse of low pH (like 4)

32 Effect of Dye Concentration Effect of concentrationon adsorption of MB onto PLC was studied by varyingconcentration from 50 to 200mgdm3 Second-order kineticparameters are shown in Table 2 It could be noticed thatadsorption rate constant 1198961198962 decreased with increase inconcentration of the dye Meanwhile maximum specicuptake increased with increase in initial concentrationeseobservations were consistent with earlier reports [3 32ndash37]In order to predict the kinetic parameters 1198961198962 in terms of initialdye concentration following models was proposed [38]

1198961198962 =1198861198861119862119862011988611988621198621198620 + 1198861198863

(6)

Regression coefficients (1198861198861 1198861198862 and 1198861198863) and coefficient ofdeterminations (1198771198772) were determined using nonlinear regres-sion Substituting the regression coefficients the followingempirical equation was obtained

1198961198962 =0018711986211986207491198621198620 minus 26983

1198771198772 = 9825 (7)

Comparison of predicted pseudo-second-order kinetics withthe experimental data is shown in Figure 2

33 Effect of Adsorbent Dosage Figure 3 illustrates the effectof adsorbent dosage on adsorption of MB Dye uptake wasfound to decrease with increase adsorbent dosage is wasdue to the fact that at smaller adsorbent dosages fraction ofactive sites saturated with dye increases is was consistentwith previous reports [29] It was evident from this gurethat initial rate of adsorption was much higher when theadsorbent dosage was higher e values of kinetic param-eters along with initial adsorption rate are given in Table 2Initial rate of adsorption is dened as the product of kineticrate constant and square of equilibrium uptake (ℎ = 1198961198962119902119902

2119890119890

mg gminus1minminus1) [29]

34 Effect of Temperature Effect of temperature is shown inFigure 4 Pseudo-second-order model ts the experimentaldata very well and the kinetic parameters are shown in Table2 along with the regression coefficients Uptake decreaseswith increase in temperature while kinetic constant increasewith increase in temperature Temperature dependency ofthe rate constant was exponential and follows Arrheniuslaw [38] A plot of ln 1198961198962 versus 1119879119879 was a straight line(plot not shown here) Activation energy of the process wasdetermined from the slope of the Arrhenius plot It was foundto be 3395 kJmol

0

10

20

30

40

50

60

70

0 50 100 150 200

Lang

Freundlich

F 5 Equilibrium curve for adsorption of MB onto PLC at303K (agitation speed = 200 RPM dosage= 2 gdm3 particle size =125 120583120583m)

T 3 Equilibrium parameters for adsorption of MB onto PLC

Langmuir Freundlich119870119870119871119871 dm

3mg 0205 119870119870119865119865 (mgg) (dm3mg)1119899119899 2036119902119902max mgg 6122 119873119873 4411205941205942 1124 1205941205942 12871198771198772 9433 1198771198772 9229

35 Equilibrium Best tting isotherm model was found byusing least squaremethod and byminimizing nonlinear errorfunction1205941205942 [39ndash41] It was found that Langmuirmodel t thedata well with high 1198771198772 and low chi2 values when comparedto that of Freundlich model e Langmuir and Freundlichisotherm parameters at 303K are given in Table 3 along with1198771198772 and 1205941205942 values [39ndash41] e comparison of experimentaldata with the predicted values at 303K is given in Figure 5Dimensionless parameter 119877119877119871119871 suggests that adsorption of MBonto PLC is a feasible process A comparison of adsorptionpotential of PLC with other adsorbents reported recentlyin the literature is given in Table 4 It could be seen thatadsorption of potential of PLC was low compared to thatof various activated carbons is is expected and logical asthe PLC reported in this study is not activated Howeverthe adsorption potential of PLC was better than that ofmany naturalunmodied alternate adsorbents reported inthe literature

36 ermodynamic Analysis e Langmuir parameter 119870119870119871119871was used to determine the thermodynamic parameter Gibbrsquosfree energy change which is an indicator of feasibility of theadsorption process Meanwhile a plot of ln 119870119870119871119871 versus 1119879119879(gure not shown here) gives other thermodynamic param-eters namely enthalpy and entropy changes of adsorptionprocess ese values are shown in Table 5 Negative values

Journal of Chemistry 5

T 4 Comparison of adsorption capacities of low cost adsorbents

Adsorbent Adsorption potential (mgg) ReferenceGrass waste (GW) 457640 [22]Jackfruit peel (JFP) 285713 [23]Rejected tea (RT) 147ndash156 [24]PLC 6122 Present studyWheat shell 1656ndash2150 [2]Posidonia oceanica (L) bres 556 [25]Pretreated dead Streptomyces rimosus 693ndash986 [26]

T 5 ermodynamics parameters for adsorption of MB ontoPLC

T (K) ΔG (JmoL) ΔH (JmoL) ΔS (Jmol K) 1198771198772

293 minus216500

231464 1531 09957303 minus233236313 minus247481323 minus262706

of Δ119866119866 indicate the feasibility of the process Positive value ofother Δ119867119867 indicates that the process is endothermic PositiveΔ119878119878 indicated increased disorder of the dye molecules on thesolid surface aer adsorption Low value of Δ119867119867 also suggeststhat the adsorptionmay be due to physical binding forceseearlier observation increasing dye uptake with increasingtemperature is also consistent with this nding

4 Conclusion

Adsorption of MB onto carbon derived from plant leaves(PLC) an agro-waste was studied Effects of variables likeinitial solution pH initial dye concentration amount ofadsorbent used and solution temperature were studied inbatch mode Adsorption kinetics was well described bypseudo-second-ordermodel UsingArrhenius equation acti-vation energy of MB adsorption on PLC was estimated to be3335 kJmol Langmuir monolayer adsorption capacity (119902119902119898119898)was determined to be 6122mgg From the thermodynamicparameters it can be concluded that the process was spon-taneous endothermic physisorption From the results of thestudy it could be concluded that PLC can be effectively usedfor the removal of methylene blue from aqueous solutions

References

[1] Y Bulut and H Aydin ldquoA kinetics and thermodynamics studyofmethylene blue adsorption onwheat shellsrdquoDesalination vol194 no 1ndash3 pp 259ndash267 2006

[2] RGong Y Jin J Chen YHu and J Sun ldquoRemoval of basic dyesfromaqueous solution by sorption on phosphoric acidmodiedrice strawrdquoDyes and Pigments vol 73 no 3 pp 332ndash337 2007

[3] V S Mane I D Mall and V C Srivastava ldquoUse of bagassey ash as an adsorbent for the removal of brilliant green dyefrom aqueous solutionrdquo Dyes and Pigments vol 73 no 3 pp269ndash278 2007

[4] N Yeddou and A Bensmaili ldquoKinetic models for the sorptionof dye from aqueous solution by clay-wood sawdust mixturerdquoDesalination vol 185 no 1ndash3 pp 499ndash508 2005

[5] P Nigam I M Banat D Singh and R Marchant ldquoMicrobialprocess for the decolorization of textile effluent containing azodiazo and reactive dyesrdquo Process Biochemistry vol 31 no 5 pp435ndash442 1996

[6] S Wang and H Li ldquoKinetic modelling and mechanism of dyeadsorption on unburned carbonrdquo Dyes and Pigments vol 72no 3 pp 308ndash314 2007

[7] H Aydin and G Baysal ldquoAdsorption of acid dyes in aqueoussolutions by shells of bittim (Pistacia khinjuk Stocks)rdquo Desali-nation vol 196 no 1ndash3 pp 248ndash259 2006

[8] M C Shih ldquoKinetics of the batch adsorption of methyleneblue from aqueous solutions onto rice husk effect of acid-modied process and dye concentrationrdquo Desalination andWater Treatment vol 37 no 1ndash3 pp 200ndash214 2012

[9] V Ponnusami V Krithika R Madhuram and S N SrivastavaldquoBiosorption of reactive dye using acid-treated rice huskfactorial design analysisrdquo Journal of Hazardous Materials vol142 no 1-2 pp 397ndash403 2007

[10] K S Low C K Lee and K K Tan ldquoBiosorption of basic dyesby water hyacinth rootsrdquo Bioresource Technology vol 52 no 1pp 79ndash83 1995

[11] V K Garg R Gupta A B Yadav and R Kumar ldquoDye removalfrom aqueous solution by adsorption on treated sawdustrdquoBioresource Technology vol 89 no 2 pp 121ndash124 2003

[12] M Bustard G McMullan and A P McHale ldquoBiosorption oftextile dyes by biomass derived fromKluyveromycesmarxianusIMB3rdquo Bioprocess Engineering vol 19 no 6 pp 427ndash430 1998

[13] T V N Padmesh K Vijayaraghavan G Sekaran andM VelanldquoBiosorption ofAcid Blue 15 using freshwatermacroalgaAzollaliculoides batch and column studiesrdquo Dyes and Pigments vol71 no 2 pp 77ndash82 2006

[14] R Prabakaran and S Arivoli ldquoermodynamic and isothermanalysis on the removal of malachite green dye using thespesiapopulnea barkrdquo E-Journal of Chemistry vol 9 no 4 pp2575ndash2588 2012

[15] R Parimalam V Raj and P Sivakumar ldquoRemoval of acidgreen 25 from aqueous solution by adsorptionrdquo E-Journal ofChemistry vol 9 no 4 pp 1683ndash1698 2012

[16] T Smitha S irumalisamy and S Manonmani ldquoEquilibriumand kinetics study of adsorption of crystal violet onto the peelof cucumis sativa fruit from aqueous solutionrdquo E-Journal ofChemistry vol 9 pp 1091ndash1101 2012

[17] Y Guo J Zhao H Zhang et al ldquoUse of rice husk-based porouscarbon for adsorption of RhodamineB fromaqueous solutionsrdquoDyes and Pigments vol 66 no 2 pp 123ndash128 2005

6 Journal of Chemistry

[18] A Jumasiah T G Chuah J Gimbon T S Y Choong andI Azni ldquoAdsorption of basic dye onto palm kernel shellactivated carbon sorption equilibrium and kinetics studiesrdquoDesalination vol 186 no 1ndash3 pp 57ndash64 2005

[19] N Kannan and M M Sundaram ldquoKinetics and mechanism ofremoval ofmethylene blue by adsorption on various carbonsmdashacomparative studyrdquoDyes and Pigments vol 51 no 1 pp 25ndash402001

[20] P K Malik ldquoUse of activated carbons prepared from sawdustand rice-husk for adsoprtion of acid dyes a case study of acidyellow 36rdquoDyes and Pigments vol 56 no 3 pp 239ndash249 2003

[21] P Janoš P Michaacutelek and L Turek ldquoSorption of ionic dyes ontountreated low-rank coalmdashoxihumolite a kinetic studyrdquo Dyesand Pigments vol 74 no 2 pp 363ndash370 2007

[22] B H Hameed ldquoGrass waste a novel sorbent for the removalof basic dye from aqueous solutionrdquo Journal of HazardousMaterials vol 166 no 1 pp 233ndash238 2009

[23] B H Hameed ldquoRemoval of cationic dye from aqueous solutionusing jackfruit peel as non-conventional low-cost adsorbentrdquoJournal of Hazardous Materials vol 162 no 1 pp 344ndash3502009

[24] N Nasuha B H Hameed and A T M Din ldquoRejected tea as apotential low-cost adsorbent for the removal ofmethylene bluerdquoJournal of Hazardous Materials vol 175 no 1ndash3 pp 126ndash1322010

[25] N Nasuha B H Hameed and A T M Din ldquoRejected tea as apotential low-cost adsorbent for the removal ofmethylene bluerdquoJournal of Hazardous Materials vol 175 no 1ndash3 pp 126ndash1322010

[26] M C Ncibi B Mahjoub and M Seffen ldquoKinetic and equi-librium studies of methylene blue biosorption by Posidoniaoceanica (L) bresrdquo Journal of Hazardous Materials vol 139no 2 pp 280ndash285 2007

[27] Y S Ho and G McKay ldquoPseudo-second order model forsorption processesrdquo Process Biochemistry vol 34 no 5 pp451ndash465 1999

[28] Y S Ho and G McKay ldquoe kinetics of sorption of divalentmetal ions onto sphagnum moss peatrdquoWater Research vol 34no 3 pp 735ndash742 2000

[29] Y S Ho and G McKay ldquoA kinetic study of dye sorption bybiosorbent waste product pithrdquo Resources Conservation andRecycling vol 25 no 3-4 pp 171ndash193 1999

[30] I Langmuir ldquoe constitution and fundamental properties ofsolids and liquids Part I Solidsrdquo e Journal of the AmericanChemical Society vol 38 no 2 pp 2221ndash2295 1916

[31] H M F Freundlich ldquoUber die adsorption in losungenrdquoZeitschri fuumlr Physikalische Chemie vol 57 pp 385ndash470 1906

[32] V Ponnusami S Vikram and S N Srivastava ldquoGuava (Psidiumguajava) leaf powder novel adsorbent for removal ofmethyleneblue from aqueous solutionsrdquo Journal of Hazardous Materialsvol 152 no 1 pp 276ndash286 2008

[33] V Ponnusami V Gunasekar and S N Srivastava ldquoKinetics ofmethylene blue removal from aqueous solution using gulmo-har (Delonix regia) plant leaf powder multivariate regressionanalysisrdquo Journal of Hazardous Materials vol 169 no 1ndash3 pp119ndash127 2009

[34] B HHameed ldquoEquilibrium and kinetic studies ofmethyl violetsorption by agricultural wasterdquo Journal of Hazardous Materialsvol 154 no 1ndash3 pp 204ndash212 2008

[35] B H Hameed A L Ahmad and K N A Latiff ldquoAdsorption ofbasic dye (methylene blue) onto activated carbon prepared from

rattan sawdustrdquo Dyes and Pigments vol 75 no 1 pp 143ndash1492007

[36] B H Hameed and F B M Daud ldquoAdsorption studies of basicdye on activated carbon derived from agricultural waste heveabrasiliensis seed coatrdquo Chemical Engineering Journal vol 139no 1 pp 48ndash55 2008

[37] M I El-Khaiary ldquoKinetics and mechanism of adsorption ofmethylene blue from aqueous solution by nitric-acid treatedwater-hyacinthrdquo Journal of Hazardous Materials vol 147 no1-2 pp 28ndash36 2007

[38] Y S Ho and G McKay ldquoSorption of dye from aqueous solutionby peatrdquo Chemical Engineering Journal vol 70 no 2 pp115ndash124 1998

[39] Y SHo ldquoSelection of optimum sorption isothermrdquoCarbon vol42 no 10 pp 2115ndash2116 2004

[40] G Crini H N Peindy F Gimbert and C Robert ldquoRemoval ofCI Basic Green 4 (Malachite Green) from aqueous solutionsby adsorption using cyclodextrin-based adsorbent kinetic andequilibrium studiesrdquo Searation and Purication Technologyvol 53 no 1 pp 97ndash110 2007

[41] Y SHoWTChiu andCCWang ldquoRegression analysis for thesorption isotherms of basic dyes on sugarcane dustrdquo BioresourceTechnology vol 96 no 11 pp 1285ndash1291 2005

Submit your manuscripts athttpwwwhindawicom

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Carbohydrate Chemistry

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom

International Journal of

Analytical ChemistryVolume 2013

ISRN Chromatography

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawi Publishing Corporation httpwwwhindawicom Volume 2013

The Scientific World Journal

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

CatalystsJournal of

ISRN Analytical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Advances in

Physical Chemistry

ISRN Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

ISRN Inorganic Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Journal of

Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2013

ISRN Organic Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Journal of

Spectroscopy

4 Journal of Chemistry

not be solely responsible for the dye adsorption on PLCSince PLC used in this study had not been activated (doesnot contain active sites) this may be possible However thisobservation suggests that more detailed study is requiredEstimated pseudo-second-order kinetic parameters are listedin Table 1 High 1198771198772 value conrms the suitability of pseudo-second-order model to explain the kinetics ofMB adsorptiononto PLC However the remaining studies were conducted atpH 7 to avoid possible operational difficulties involved in theuse of low pH (like 4)

32 Effect of Dye Concentration Effect of concentrationon adsorption of MB onto PLC was studied by varyingconcentration from 50 to 200mgdm3 Second-order kineticparameters are shown in Table 2 It could be noticed thatadsorption rate constant 1198961198962 decreased with increase inconcentration of the dye Meanwhile maximum specicuptake increased with increase in initial concentrationeseobservations were consistent with earlier reports [3 32ndash37]In order to predict the kinetic parameters 1198961198962 in terms of initialdye concentration following models was proposed [38]

1198961198962 =1198861198861119862119862011988611988621198621198620 + 1198861198863

(6)

Regression coefficients (1198861198861 1198861198862 and 1198861198863) and coefficient ofdeterminations (1198771198772) were determined using nonlinear regres-sion Substituting the regression coefficients the followingempirical equation was obtained

1198961198962 =0018711986211986207491198621198620 minus 26983

1198771198772 = 9825 (7)

Comparison of predicted pseudo-second-order kinetics withthe experimental data is shown in Figure 2

33 Effect of Adsorbent Dosage Figure 3 illustrates the effectof adsorbent dosage on adsorption of MB Dye uptake wasfound to decrease with increase adsorbent dosage is wasdue to the fact that at smaller adsorbent dosages fraction ofactive sites saturated with dye increases is was consistentwith previous reports [29] It was evident from this gurethat initial rate of adsorption was much higher when theadsorbent dosage was higher e values of kinetic param-eters along with initial adsorption rate are given in Table 2Initial rate of adsorption is dened as the product of kineticrate constant and square of equilibrium uptake (ℎ = 1198961198962119902119902

2119890119890

mg gminus1minminus1) [29]

34 Effect of Temperature Effect of temperature is shown inFigure 4 Pseudo-second-order model ts the experimentaldata very well and the kinetic parameters are shown in Table2 along with the regression coefficients Uptake decreaseswith increase in temperature while kinetic constant increasewith increase in temperature Temperature dependency ofthe rate constant was exponential and follows Arrheniuslaw [38] A plot of ln 1198961198962 versus 1119879119879 was a straight line(plot not shown here) Activation energy of the process wasdetermined from the slope of the Arrhenius plot It was foundto be 3395 kJmol

0

10

20

30

40

50

60

70

0 50 100 150 200

Lang

Freundlich

F 5 Equilibrium curve for adsorption of MB onto PLC at303K (agitation speed = 200 RPM dosage= 2 gdm3 particle size =125 120583120583m)

T 3 Equilibrium parameters for adsorption of MB onto PLC

Langmuir Freundlich119870119870119871119871 dm

3mg 0205 119870119870119865119865 (mgg) (dm3mg)1119899119899 2036119902119902max mgg 6122 119873119873 4411205941205942 1124 1205941205942 12871198771198772 9433 1198771198772 9229

35 Equilibrium Best tting isotherm model was found byusing least squaremethod and byminimizing nonlinear errorfunction1205941205942 [39ndash41] It was found that Langmuirmodel t thedata well with high 1198771198772 and low chi2 values when comparedto that of Freundlich model e Langmuir and Freundlichisotherm parameters at 303K are given in Table 3 along with1198771198772 and 1205941205942 values [39ndash41] e comparison of experimentaldata with the predicted values at 303K is given in Figure 5Dimensionless parameter 119877119877119871119871 suggests that adsorption of MBonto PLC is a feasible process A comparison of adsorptionpotential of PLC with other adsorbents reported recentlyin the literature is given in Table 4 It could be seen thatadsorption of potential of PLC was low compared to thatof various activated carbons is is expected and logical asthe PLC reported in this study is not activated Howeverthe adsorption potential of PLC was better than that ofmany naturalunmodied alternate adsorbents reported inthe literature

36 ermodynamic Analysis e Langmuir parameter 119870119870119871119871was used to determine the thermodynamic parameter Gibbrsquosfree energy change which is an indicator of feasibility of theadsorption process Meanwhile a plot of ln 119870119870119871119871 versus 1119879119879(gure not shown here) gives other thermodynamic param-eters namely enthalpy and entropy changes of adsorptionprocess ese values are shown in Table 5 Negative values

Journal of Chemistry 5

T 4 Comparison of adsorption capacities of low cost adsorbents

Adsorbent Adsorption potential (mgg) ReferenceGrass waste (GW) 457640 [22]Jackfruit peel (JFP) 285713 [23]Rejected tea (RT) 147ndash156 [24]PLC 6122 Present studyWheat shell 1656ndash2150 [2]Posidonia oceanica (L) bres 556 [25]Pretreated dead Streptomyces rimosus 693ndash986 [26]

T 5 ermodynamics parameters for adsorption of MB ontoPLC

T (K) ΔG (JmoL) ΔH (JmoL) ΔS (Jmol K) 1198771198772

293 minus216500

231464 1531 09957303 minus233236313 minus247481323 minus262706

of Δ119866119866 indicate the feasibility of the process Positive value ofother Δ119867119867 indicates that the process is endothermic PositiveΔ119878119878 indicated increased disorder of the dye molecules on thesolid surface aer adsorption Low value of Δ119867119867 also suggeststhat the adsorptionmay be due to physical binding forceseearlier observation increasing dye uptake with increasingtemperature is also consistent with this nding

4 Conclusion

Adsorption of MB onto carbon derived from plant leaves(PLC) an agro-waste was studied Effects of variables likeinitial solution pH initial dye concentration amount ofadsorbent used and solution temperature were studied inbatch mode Adsorption kinetics was well described bypseudo-second-ordermodel UsingArrhenius equation acti-vation energy of MB adsorption on PLC was estimated to be3335 kJmol Langmuir monolayer adsorption capacity (119902119902119898119898)was determined to be 6122mgg From the thermodynamicparameters it can be concluded that the process was spon-taneous endothermic physisorption From the results of thestudy it could be concluded that PLC can be effectively usedfor the removal of methylene blue from aqueous solutions

References

[1] Y Bulut and H Aydin ldquoA kinetics and thermodynamics studyofmethylene blue adsorption onwheat shellsrdquoDesalination vol194 no 1ndash3 pp 259ndash267 2006

[2] RGong Y Jin J Chen YHu and J Sun ldquoRemoval of basic dyesfromaqueous solution by sorption on phosphoric acidmodiedrice strawrdquoDyes and Pigments vol 73 no 3 pp 332ndash337 2007

[3] V S Mane I D Mall and V C Srivastava ldquoUse of bagassey ash as an adsorbent for the removal of brilliant green dyefrom aqueous solutionrdquo Dyes and Pigments vol 73 no 3 pp269ndash278 2007

[4] N Yeddou and A Bensmaili ldquoKinetic models for the sorptionof dye from aqueous solution by clay-wood sawdust mixturerdquoDesalination vol 185 no 1ndash3 pp 499ndash508 2005

[5] P Nigam I M Banat D Singh and R Marchant ldquoMicrobialprocess for the decolorization of textile effluent containing azodiazo and reactive dyesrdquo Process Biochemistry vol 31 no 5 pp435ndash442 1996

[6] S Wang and H Li ldquoKinetic modelling and mechanism of dyeadsorption on unburned carbonrdquo Dyes and Pigments vol 72no 3 pp 308ndash314 2007

[7] H Aydin and G Baysal ldquoAdsorption of acid dyes in aqueoussolutions by shells of bittim (Pistacia khinjuk Stocks)rdquo Desali-nation vol 196 no 1ndash3 pp 248ndash259 2006

[8] M C Shih ldquoKinetics of the batch adsorption of methyleneblue from aqueous solutions onto rice husk effect of acid-modied process and dye concentrationrdquo Desalination andWater Treatment vol 37 no 1ndash3 pp 200ndash214 2012

[9] V Ponnusami V Krithika R Madhuram and S N SrivastavaldquoBiosorption of reactive dye using acid-treated rice huskfactorial design analysisrdquo Journal of Hazardous Materials vol142 no 1-2 pp 397ndash403 2007

[10] K S Low C K Lee and K K Tan ldquoBiosorption of basic dyesby water hyacinth rootsrdquo Bioresource Technology vol 52 no 1pp 79ndash83 1995

[11] V K Garg R Gupta A B Yadav and R Kumar ldquoDye removalfrom aqueous solution by adsorption on treated sawdustrdquoBioresource Technology vol 89 no 2 pp 121ndash124 2003

[12] M Bustard G McMullan and A P McHale ldquoBiosorption oftextile dyes by biomass derived fromKluyveromycesmarxianusIMB3rdquo Bioprocess Engineering vol 19 no 6 pp 427ndash430 1998

[13] T V N Padmesh K Vijayaraghavan G Sekaran andM VelanldquoBiosorption ofAcid Blue 15 using freshwatermacroalgaAzollaliculoides batch and column studiesrdquo Dyes and Pigments vol71 no 2 pp 77ndash82 2006

[14] R Prabakaran and S Arivoli ldquoermodynamic and isothermanalysis on the removal of malachite green dye using thespesiapopulnea barkrdquo E-Journal of Chemistry vol 9 no 4 pp2575ndash2588 2012

[15] R Parimalam V Raj and P Sivakumar ldquoRemoval of acidgreen 25 from aqueous solution by adsorptionrdquo E-Journal ofChemistry vol 9 no 4 pp 1683ndash1698 2012

[16] T Smitha S irumalisamy and S Manonmani ldquoEquilibriumand kinetics study of adsorption of crystal violet onto the peelof cucumis sativa fruit from aqueous solutionrdquo E-Journal ofChemistry vol 9 pp 1091ndash1101 2012

[17] Y Guo J Zhao H Zhang et al ldquoUse of rice husk-based porouscarbon for adsorption of RhodamineB fromaqueous solutionsrdquoDyes and Pigments vol 66 no 2 pp 123ndash128 2005

6 Journal of Chemistry

[18] A Jumasiah T G Chuah J Gimbon T S Y Choong andI Azni ldquoAdsorption of basic dye onto palm kernel shellactivated carbon sorption equilibrium and kinetics studiesrdquoDesalination vol 186 no 1ndash3 pp 57ndash64 2005

[19] N Kannan and M M Sundaram ldquoKinetics and mechanism ofremoval ofmethylene blue by adsorption on various carbonsmdashacomparative studyrdquoDyes and Pigments vol 51 no 1 pp 25ndash402001

[20] P K Malik ldquoUse of activated carbons prepared from sawdustand rice-husk for adsoprtion of acid dyes a case study of acidyellow 36rdquoDyes and Pigments vol 56 no 3 pp 239ndash249 2003

[21] P Janoš P Michaacutelek and L Turek ldquoSorption of ionic dyes ontountreated low-rank coalmdashoxihumolite a kinetic studyrdquo Dyesand Pigments vol 74 no 2 pp 363ndash370 2007

[22] B H Hameed ldquoGrass waste a novel sorbent for the removalof basic dye from aqueous solutionrdquo Journal of HazardousMaterials vol 166 no 1 pp 233ndash238 2009

[23] B H Hameed ldquoRemoval of cationic dye from aqueous solutionusing jackfruit peel as non-conventional low-cost adsorbentrdquoJournal of Hazardous Materials vol 162 no 1 pp 344ndash3502009

[24] N Nasuha B H Hameed and A T M Din ldquoRejected tea as apotential low-cost adsorbent for the removal ofmethylene bluerdquoJournal of Hazardous Materials vol 175 no 1ndash3 pp 126ndash1322010

[25] N Nasuha B H Hameed and A T M Din ldquoRejected tea as apotential low-cost adsorbent for the removal ofmethylene bluerdquoJournal of Hazardous Materials vol 175 no 1ndash3 pp 126ndash1322010

[26] M C Ncibi B Mahjoub and M Seffen ldquoKinetic and equi-librium studies of methylene blue biosorption by Posidoniaoceanica (L) bresrdquo Journal of Hazardous Materials vol 139no 2 pp 280ndash285 2007

[27] Y S Ho and G McKay ldquoPseudo-second order model forsorption processesrdquo Process Biochemistry vol 34 no 5 pp451ndash465 1999

[28] Y S Ho and G McKay ldquoe kinetics of sorption of divalentmetal ions onto sphagnum moss peatrdquoWater Research vol 34no 3 pp 735ndash742 2000

[29] Y S Ho and G McKay ldquoA kinetic study of dye sorption bybiosorbent waste product pithrdquo Resources Conservation andRecycling vol 25 no 3-4 pp 171ndash193 1999

[30] I Langmuir ldquoe constitution and fundamental properties ofsolids and liquids Part I Solidsrdquo e Journal of the AmericanChemical Society vol 38 no 2 pp 2221ndash2295 1916

[31] H M F Freundlich ldquoUber die adsorption in losungenrdquoZeitschri fuumlr Physikalische Chemie vol 57 pp 385ndash470 1906

[32] V Ponnusami S Vikram and S N Srivastava ldquoGuava (Psidiumguajava) leaf powder novel adsorbent for removal ofmethyleneblue from aqueous solutionsrdquo Journal of Hazardous Materialsvol 152 no 1 pp 276ndash286 2008

[33] V Ponnusami V Gunasekar and S N Srivastava ldquoKinetics ofmethylene blue removal from aqueous solution using gulmo-har (Delonix regia) plant leaf powder multivariate regressionanalysisrdquo Journal of Hazardous Materials vol 169 no 1ndash3 pp119ndash127 2009

[34] B HHameed ldquoEquilibrium and kinetic studies ofmethyl violetsorption by agricultural wasterdquo Journal of Hazardous Materialsvol 154 no 1ndash3 pp 204ndash212 2008

[35] B H Hameed A L Ahmad and K N A Latiff ldquoAdsorption ofbasic dye (methylene blue) onto activated carbon prepared from

rattan sawdustrdquo Dyes and Pigments vol 75 no 1 pp 143ndash1492007

[36] B H Hameed and F B M Daud ldquoAdsorption studies of basicdye on activated carbon derived from agricultural waste heveabrasiliensis seed coatrdquo Chemical Engineering Journal vol 139no 1 pp 48ndash55 2008

[37] M I El-Khaiary ldquoKinetics and mechanism of adsorption ofmethylene blue from aqueous solution by nitric-acid treatedwater-hyacinthrdquo Journal of Hazardous Materials vol 147 no1-2 pp 28ndash36 2007

[38] Y S Ho and G McKay ldquoSorption of dye from aqueous solutionby peatrdquo Chemical Engineering Journal vol 70 no 2 pp115ndash124 1998

[39] Y SHo ldquoSelection of optimum sorption isothermrdquoCarbon vol42 no 10 pp 2115ndash2116 2004

[40] G Crini H N Peindy F Gimbert and C Robert ldquoRemoval ofCI Basic Green 4 (Malachite Green) from aqueous solutionsby adsorption using cyclodextrin-based adsorbent kinetic andequilibrium studiesrdquo Searation and Purication Technologyvol 53 no 1 pp 97ndash110 2007

[41] Y SHoWTChiu andCCWang ldquoRegression analysis for thesorption isotherms of basic dyes on sugarcane dustrdquo BioresourceTechnology vol 96 no 11 pp 1285ndash1291 2005

Submit your manuscripts athttpwwwhindawicom

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Carbohydrate Chemistry

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom

International Journal of

Analytical ChemistryVolume 2013

ISRN Chromatography

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawi Publishing Corporation httpwwwhindawicom Volume 2013

The Scientific World Journal

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

CatalystsJournal of

ISRN Analytical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Advances in

Physical Chemistry

ISRN Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

ISRN Inorganic Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Journal of

Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2013

ISRN Organic Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Journal of

Spectroscopy

Journal of Chemistry 5

T 4 Comparison of adsorption capacities of low cost adsorbents

Adsorbent Adsorption potential (mgg) ReferenceGrass waste (GW) 457640 [22]Jackfruit peel (JFP) 285713 [23]Rejected tea (RT) 147ndash156 [24]PLC 6122 Present studyWheat shell 1656ndash2150 [2]Posidonia oceanica (L) bres 556 [25]Pretreated dead Streptomyces rimosus 693ndash986 [26]

T 5 ermodynamics parameters for adsorption of MB ontoPLC

T (K) ΔG (JmoL) ΔH (JmoL) ΔS (Jmol K) 1198771198772

293 minus216500

231464 1531 09957303 minus233236313 minus247481323 minus262706

of Δ119866119866 indicate the feasibility of the process Positive value ofother Δ119867119867 indicates that the process is endothermic PositiveΔ119878119878 indicated increased disorder of the dye molecules on thesolid surface aer adsorption Low value of Δ119867119867 also suggeststhat the adsorptionmay be due to physical binding forceseearlier observation increasing dye uptake with increasingtemperature is also consistent with this nding

4 Conclusion

Adsorption of MB onto carbon derived from plant leaves(PLC) an agro-waste was studied Effects of variables likeinitial solution pH initial dye concentration amount ofadsorbent used and solution temperature were studied inbatch mode Adsorption kinetics was well described bypseudo-second-ordermodel UsingArrhenius equation acti-vation energy of MB adsorption on PLC was estimated to be3335 kJmol Langmuir monolayer adsorption capacity (119902119902119898119898)was determined to be 6122mgg From the thermodynamicparameters it can be concluded that the process was spon-taneous endothermic physisorption From the results of thestudy it could be concluded that PLC can be effectively usedfor the removal of methylene blue from aqueous solutions

References

[1] Y Bulut and H Aydin ldquoA kinetics and thermodynamics studyofmethylene blue adsorption onwheat shellsrdquoDesalination vol194 no 1ndash3 pp 259ndash267 2006

[2] RGong Y Jin J Chen YHu and J Sun ldquoRemoval of basic dyesfromaqueous solution by sorption on phosphoric acidmodiedrice strawrdquoDyes and Pigments vol 73 no 3 pp 332ndash337 2007

[3] V S Mane I D Mall and V C Srivastava ldquoUse of bagassey ash as an adsorbent for the removal of brilliant green dyefrom aqueous solutionrdquo Dyes and Pigments vol 73 no 3 pp269ndash278 2007

[4] N Yeddou and A Bensmaili ldquoKinetic models for the sorptionof dye from aqueous solution by clay-wood sawdust mixturerdquoDesalination vol 185 no 1ndash3 pp 499ndash508 2005

[5] P Nigam I M Banat D Singh and R Marchant ldquoMicrobialprocess for the decolorization of textile effluent containing azodiazo and reactive dyesrdquo Process Biochemistry vol 31 no 5 pp435ndash442 1996

[6] S Wang and H Li ldquoKinetic modelling and mechanism of dyeadsorption on unburned carbonrdquo Dyes and Pigments vol 72no 3 pp 308ndash314 2007

[7] H Aydin and G Baysal ldquoAdsorption of acid dyes in aqueoussolutions by shells of bittim (Pistacia khinjuk Stocks)rdquo Desali-nation vol 196 no 1ndash3 pp 248ndash259 2006

[8] M C Shih ldquoKinetics of the batch adsorption of methyleneblue from aqueous solutions onto rice husk effect of acid-modied process and dye concentrationrdquo Desalination andWater Treatment vol 37 no 1ndash3 pp 200ndash214 2012

[9] V Ponnusami V Krithika R Madhuram and S N SrivastavaldquoBiosorption of reactive dye using acid-treated rice huskfactorial design analysisrdquo Journal of Hazardous Materials vol142 no 1-2 pp 397ndash403 2007

[10] K S Low C K Lee and K K Tan ldquoBiosorption of basic dyesby water hyacinth rootsrdquo Bioresource Technology vol 52 no 1pp 79ndash83 1995

[11] V K Garg R Gupta A B Yadav and R Kumar ldquoDye removalfrom aqueous solution by adsorption on treated sawdustrdquoBioresource Technology vol 89 no 2 pp 121ndash124 2003

[12] M Bustard G McMullan and A P McHale ldquoBiosorption oftextile dyes by biomass derived fromKluyveromycesmarxianusIMB3rdquo Bioprocess Engineering vol 19 no 6 pp 427ndash430 1998

[13] T V N Padmesh K Vijayaraghavan G Sekaran andM VelanldquoBiosorption ofAcid Blue 15 using freshwatermacroalgaAzollaliculoides batch and column studiesrdquo Dyes and Pigments vol71 no 2 pp 77ndash82 2006

[14] R Prabakaran and S Arivoli ldquoermodynamic and isothermanalysis on the removal of malachite green dye using thespesiapopulnea barkrdquo E-Journal of Chemistry vol 9 no 4 pp2575ndash2588 2012

[15] R Parimalam V Raj and P Sivakumar ldquoRemoval of acidgreen 25 from aqueous solution by adsorptionrdquo E-Journal ofChemistry vol 9 no 4 pp 1683ndash1698 2012

[16] T Smitha S irumalisamy and S Manonmani ldquoEquilibriumand kinetics study of adsorption of crystal violet onto the peelof cucumis sativa fruit from aqueous solutionrdquo E-Journal ofChemistry vol 9 pp 1091ndash1101 2012

[17] Y Guo J Zhao H Zhang et al ldquoUse of rice husk-based porouscarbon for adsorption of RhodamineB fromaqueous solutionsrdquoDyes and Pigments vol 66 no 2 pp 123ndash128 2005

6 Journal of Chemistry

[18] A Jumasiah T G Chuah J Gimbon T S Y Choong andI Azni ldquoAdsorption of basic dye onto palm kernel shellactivated carbon sorption equilibrium and kinetics studiesrdquoDesalination vol 186 no 1ndash3 pp 57ndash64 2005

[19] N Kannan and M M Sundaram ldquoKinetics and mechanism ofremoval ofmethylene blue by adsorption on various carbonsmdashacomparative studyrdquoDyes and Pigments vol 51 no 1 pp 25ndash402001

[20] P K Malik ldquoUse of activated carbons prepared from sawdustand rice-husk for adsoprtion of acid dyes a case study of acidyellow 36rdquoDyes and Pigments vol 56 no 3 pp 239ndash249 2003

[21] P Janoš P Michaacutelek and L Turek ldquoSorption of ionic dyes ontountreated low-rank coalmdashoxihumolite a kinetic studyrdquo Dyesand Pigments vol 74 no 2 pp 363ndash370 2007

[22] B H Hameed ldquoGrass waste a novel sorbent for the removalof basic dye from aqueous solutionrdquo Journal of HazardousMaterials vol 166 no 1 pp 233ndash238 2009

[23] B H Hameed ldquoRemoval of cationic dye from aqueous solutionusing jackfruit peel as non-conventional low-cost adsorbentrdquoJournal of Hazardous Materials vol 162 no 1 pp 344ndash3502009

[24] N Nasuha B H Hameed and A T M Din ldquoRejected tea as apotential low-cost adsorbent for the removal ofmethylene bluerdquoJournal of Hazardous Materials vol 175 no 1ndash3 pp 126ndash1322010

[25] N Nasuha B H Hameed and A T M Din ldquoRejected tea as apotential low-cost adsorbent for the removal ofmethylene bluerdquoJournal of Hazardous Materials vol 175 no 1ndash3 pp 126ndash1322010

[26] M C Ncibi B Mahjoub and M Seffen ldquoKinetic and equi-librium studies of methylene blue biosorption by Posidoniaoceanica (L) bresrdquo Journal of Hazardous Materials vol 139no 2 pp 280ndash285 2007

[27] Y S Ho and G McKay ldquoPseudo-second order model forsorption processesrdquo Process Biochemistry vol 34 no 5 pp451ndash465 1999

[28] Y S Ho and G McKay ldquoe kinetics of sorption of divalentmetal ions onto sphagnum moss peatrdquoWater Research vol 34no 3 pp 735ndash742 2000

[29] Y S Ho and G McKay ldquoA kinetic study of dye sorption bybiosorbent waste product pithrdquo Resources Conservation andRecycling vol 25 no 3-4 pp 171ndash193 1999

[30] I Langmuir ldquoe constitution and fundamental properties ofsolids and liquids Part I Solidsrdquo e Journal of the AmericanChemical Society vol 38 no 2 pp 2221ndash2295 1916

[31] H M F Freundlich ldquoUber die adsorption in losungenrdquoZeitschri fuumlr Physikalische Chemie vol 57 pp 385ndash470 1906

[32] V Ponnusami S Vikram and S N Srivastava ldquoGuava (Psidiumguajava) leaf powder novel adsorbent for removal ofmethyleneblue from aqueous solutionsrdquo Journal of Hazardous Materialsvol 152 no 1 pp 276ndash286 2008

[33] V Ponnusami V Gunasekar and S N Srivastava ldquoKinetics ofmethylene blue removal from aqueous solution using gulmo-har (Delonix regia) plant leaf powder multivariate regressionanalysisrdquo Journal of Hazardous Materials vol 169 no 1ndash3 pp119ndash127 2009

[34] B HHameed ldquoEquilibrium and kinetic studies ofmethyl violetsorption by agricultural wasterdquo Journal of Hazardous Materialsvol 154 no 1ndash3 pp 204ndash212 2008

[35] B H Hameed A L Ahmad and K N A Latiff ldquoAdsorption ofbasic dye (methylene blue) onto activated carbon prepared from

rattan sawdustrdquo Dyes and Pigments vol 75 no 1 pp 143ndash1492007

[36] B H Hameed and F B M Daud ldquoAdsorption studies of basicdye on activated carbon derived from agricultural waste heveabrasiliensis seed coatrdquo Chemical Engineering Journal vol 139no 1 pp 48ndash55 2008

[37] M I El-Khaiary ldquoKinetics and mechanism of adsorption ofmethylene blue from aqueous solution by nitric-acid treatedwater-hyacinthrdquo Journal of Hazardous Materials vol 147 no1-2 pp 28ndash36 2007

[38] Y S Ho and G McKay ldquoSorption of dye from aqueous solutionby peatrdquo Chemical Engineering Journal vol 70 no 2 pp115ndash124 1998

[39] Y SHo ldquoSelection of optimum sorption isothermrdquoCarbon vol42 no 10 pp 2115ndash2116 2004

[40] G Crini H N Peindy F Gimbert and C Robert ldquoRemoval ofCI Basic Green 4 (Malachite Green) from aqueous solutionsby adsorption using cyclodextrin-based adsorbent kinetic andequilibrium studiesrdquo Searation and Purication Technologyvol 53 no 1 pp 97ndash110 2007

[41] Y SHoWTChiu andCCWang ldquoRegression analysis for thesorption isotherms of basic dyes on sugarcane dustrdquo BioresourceTechnology vol 96 no 11 pp 1285ndash1291 2005

Submit your manuscripts athttpwwwhindawicom

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Carbohydrate Chemistry

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom

International Journal of

Analytical ChemistryVolume 2013

ISRN Chromatography

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawi Publishing Corporation httpwwwhindawicom Volume 2013

The Scientific World Journal

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

CatalystsJournal of

ISRN Analytical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Advances in

Physical Chemistry

ISRN Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

ISRN Inorganic Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Journal of

Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2013

ISRN Organic Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Journal of

Spectroscopy

6 Journal of Chemistry

[18] A Jumasiah T G Chuah J Gimbon T S Y Choong andI Azni ldquoAdsorption of basic dye onto palm kernel shellactivated carbon sorption equilibrium and kinetics studiesrdquoDesalination vol 186 no 1ndash3 pp 57ndash64 2005

[19] N Kannan and M M Sundaram ldquoKinetics and mechanism ofremoval ofmethylene blue by adsorption on various carbonsmdashacomparative studyrdquoDyes and Pigments vol 51 no 1 pp 25ndash402001

[20] P K Malik ldquoUse of activated carbons prepared from sawdustand rice-husk for adsoprtion of acid dyes a case study of acidyellow 36rdquoDyes and Pigments vol 56 no 3 pp 239ndash249 2003

[21] P Janoš P Michaacutelek and L Turek ldquoSorption of ionic dyes ontountreated low-rank coalmdashoxihumolite a kinetic studyrdquo Dyesand Pigments vol 74 no 2 pp 363ndash370 2007

[22] B H Hameed ldquoGrass waste a novel sorbent for the removalof basic dye from aqueous solutionrdquo Journal of HazardousMaterials vol 166 no 1 pp 233ndash238 2009

[23] B H Hameed ldquoRemoval of cationic dye from aqueous solutionusing jackfruit peel as non-conventional low-cost adsorbentrdquoJournal of Hazardous Materials vol 162 no 1 pp 344ndash3502009

[24] N Nasuha B H Hameed and A T M Din ldquoRejected tea as apotential low-cost adsorbent for the removal ofmethylene bluerdquoJournal of Hazardous Materials vol 175 no 1ndash3 pp 126ndash1322010

[25] N Nasuha B H Hameed and A T M Din ldquoRejected tea as apotential low-cost adsorbent for the removal ofmethylene bluerdquoJournal of Hazardous Materials vol 175 no 1ndash3 pp 126ndash1322010

[26] M C Ncibi B Mahjoub and M Seffen ldquoKinetic and equi-librium studies of methylene blue biosorption by Posidoniaoceanica (L) bresrdquo Journal of Hazardous Materials vol 139no 2 pp 280ndash285 2007

[27] Y S Ho and G McKay ldquoPseudo-second order model forsorption processesrdquo Process Biochemistry vol 34 no 5 pp451ndash465 1999

[28] Y S Ho and G McKay ldquoe kinetics of sorption of divalentmetal ions onto sphagnum moss peatrdquoWater Research vol 34no 3 pp 735ndash742 2000

[29] Y S Ho and G McKay ldquoA kinetic study of dye sorption bybiosorbent waste product pithrdquo Resources Conservation andRecycling vol 25 no 3-4 pp 171ndash193 1999

[30] I Langmuir ldquoe constitution and fundamental properties ofsolids and liquids Part I Solidsrdquo e Journal of the AmericanChemical Society vol 38 no 2 pp 2221ndash2295 1916

[31] H M F Freundlich ldquoUber die adsorption in losungenrdquoZeitschri fuumlr Physikalische Chemie vol 57 pp 385ndash470 1906

[32] V Ponnusami S Vikram and S N Srivastava ldquoGuava (Psidiumguajava) leaf powder novel adsorbent for removal ofmethyleneblue from aqueous solutionsrdquo Journal of Hazardous Materialsvol 152 no 1 pp 276ndash286 2008

[33] V Ponnusami V Gunasekar and S N Srivastava ldquoKinetics ofmethylene blue removal from aqueous solution using gulmo-har (Delonix regia) plant leaf powder multivariate regressionanalysisrdquo Journal of Hazardous Materials vol 169 no 1ndash3 pp119ndash127 2009

[34] B HHameed ldquoEquilibrium and kinetic studies ofmethyl violetsorption by agricultural wasterdquo Journal of Hazardous Materialsvol 154 no 1ndash3 pp 204ndash212 2008

[35] B H Hameed A L Ahmad and K N A Latiff ldquoAdsorption ofbasic dye (methylene blue) onto activated carbon prepared from

rattan sawdustrdquo Dyes and Pigments vol 75 no 1 pp 143ndash1492007

[36] B H Hameed and F B M Daud ldquoAdsorption studies of basicdye on activated carbon derived from agricultural waste heveabrasiliensis seed coatrdquo Chemical Engineering Journal vol 139no 1 pp 48ndash55 2008

[37] M I El-Khaiary ldquoKinetics and mechanism of adsorption ofmethylene blue from aqueous solution by nitric-acid treatedwater-hyacinthrdquo Journal of Hazardous Materials vol 147 no1-2 pp 28ndash36 2007

[38] Y S Ho and G McKay ldquoSorption of dye from aqueous solutionby peatrdquo Chemical Engineering Journal vol 70 no 2 pp115ndash124 1998

[39] Y SHo ldquoSelection of optimum sorption isothermrdquoCarbon vol42 no 10 pp 2115ndash2116 2004

[40] G Crini H N Peindy F Gimbert and C Robert ldquoRemoval ofCI Basic Green 4 (Malachite Green) from aqueous solutionsby adsorption using cyclodextrin-based adsorbent kinetic andequilibrium studiesrdquo Searation and Purication Technologyvol 53 no 1 pp 97ndash110 2007

[41] Y SHoWTChiu andCCWang ldquoRegression analysis for thesorption isotherms of basic dyes on sugarcane dustrdquo BioresourceTechnology vol 96 no 11 pp 1285ndash1291 2005

Submit your manuscripts athttpwwwhindawicom

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Carbohydrate Chemistry

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom

International Journal of

Analytical ChemistryVolume 2013

ISRN Chromatography

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawi Publishing Corporation httpwwwhindawicom Volume 2013

The Scientific World Journal

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

CatalystsJournal of

ISRN Analytical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Advances in

Physical Chemistry

ISRN Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

ISRN Inorganic Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Journal of

Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2013

ISRN Organic Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Journal of

Spectroscopy

Submit your manuscripts athttpwwwhindawicom

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Carbohydrate Chemistry

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom

International Journal of

Analytical ChemistryVolume 2013

ISRN Chromatography

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawi Publishing Corporation httpwwwhindawicom Volume 2013

The Scientific World Journal

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

CatalystsJournal of

ISRN Analytical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Advances in

Physical Chemistry

ISRN Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

ISRN Inorganic Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Journal of

Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2013

ISRN Organic Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Journal of

Spectroscopy