Biosorption of formic and acetic acids from aqueous solution using activated carbon from shea butter seed shells

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1 Appl Wter Sci (7) 7:77 73 DOI.7/s ORIGINAL ARTICLE Biosorption of formic nd cetic cids from queous solution using ctivted cron from she utter seed shells Folhn A. Adekol Ismil A. O Received: Decemer 5 / Accepted: Octoer / Pulished online: 8 Octoer Ó The Author(s). This rticle is pulished with open ccess t Springerlink.com Astrct The efficiency of prepred ctivted cron from she utter seed shells (SB-AC) for the dsorption of formic cid () nd cetic cid () from queous solution ws investigted. The effect of optimiztion prmeters including initil concentrtion, gittion time, dsorent dosge nd temperture of dsorte solution on the sorption cpcity were studied. The SB-AC ws chrcterized for the following prmeters: ulk density, moisture content, sh content, ph, Fourier trnsform infrred spectroscopy (FTIR) nd scnning electron microscopy (SEM). The optiml conditions for the dsorption were estlished nd the dsorption dt for fitted Duinin Rdushkevich (D R) isotherm well, wheres followed Lngmuir isotherm. The kinetic dt were exmined. It ws found tht pseudo-second-order kinetic model ws found to dequtely explin the sorption kinetic of nd from queous solution. It ws gin found tht intrprticle diffusion ws found to explin the dsorption mechnism. Adsorption thermodynmic prmeters were estimted nd the negtive vlues of DG showed tht the dsorption process ws fesile nd spontneous in nture, while the negtive vlues of DH indicte tht the dsorption process ws exothermic. It is therefore estlished tht SB-AC hs good potentil for the removl of nd from queous Electronic supplementry mteril The online version of this rticle (doi:.7/s3--9-3) contins supplementry mteril, which is ville to uthorized users. & Ismil A. O oismil@gmil.com Folhn A. Adekol fdekol@yhoo.fr Deprtment of Industril Chemistry, University of Ilorin, Ilorin P.M.B. 55, Kwr Stte, Nigeri solution. Hence, it should find ppliction in the regulr tretment of polluted wter in quculture nd fish reeding system. Keywords Adsorption Wstewter Formic cid Acetic cid Activted cron Introduction The progressive increse of industril technology results in reltive increse in environmentl pollution nd gret effort hs een mde to minimize hzrdous pollutnts nd, hence, voiding their dngerous effects on nimls, plnts nd humns (Nwnne nd Igokwe ). Wter pollution represents gret chllenge nd ctivted cron is common dsorent used to remove hzrdous contminnts from wstewter. The presence of formic cid nd cetic cid in industril effluents poses serious environmentl prolem. The mjor ill effects cused y these cids re formtion of kidney stones, vomiting nd generl ody wekness (Knnn nd Xvier ; Freits et l. 7). Thus, it is impertive tht they re removed from industril wstes efore dischrging them into the wter ody. Mny techniques hve een used in the pst for the tretment of wstewter contining these pollutnts, ut proved ineffective. Adsorption is n effective technique for the removl of the dissolved pollutnts (orgnic or inorgnic) from wter. Among mny types of dsorents, ctivted crons re the most widely used, ecuse of their lrge dsorptive cpcity nd low cost. Among the possile techniques for wter tretments, the dsorption process y solid dsorents shows potentil s one of the most efficient methods for the tretment nd removl of orgnic contminnts in wstewter tretment (Benkhedd et l. ). The dsorption cpcity 3

2 78 Appl Wter Sci (7) 7:77 73 of ctivted cron is linked to the lrge surfce re, high microporosity nd high degree of surfce rectivity (Khh nd Ansri 9). The min ojective of this study is to investigte the potentil use of ctivted cron from she utter seed shells, n griculturl wste mteril s lowcost io-dsorent for removl of nd from queous solution. Mterils nd methods Adsorent preprtion She utter seed shells were otined from she utter trees within the University of Ilorin cmpus, Nigeri. The deseeded she utter seed shells were wshed severl times, sun dried, chopped into smll pieces nd pyrolyzed t 5 C for 3 min. The cronized mterils were llowed to cool to room temperture, crushed into powder with the id of mortr nd pestle nd sieved with stndrd sieve of size Ø \ 9 lm. The cronized powdered smple otined ws wshed with de-ionized wter, filtered nd dried in the oven t 5 C. The purified ctivted cron otined ws chemiclly ctivted y. M HNO 3 solution (Adegoke nd Adekol ): g of cron smple ws contcted with ml of M solution of HNO 3 t C nd stirred for h. Therefter, it ws wshed severl times to otin neutrlity with deionized wter, filtered nd dried gin in the oven t 5 C. Chrcteriztion of ctivted cron The ctivted cron ws chrcterized for some physicochemicl properties such s sh content, moisture content, ulk density, iodine numer nd ph, which were determined in ccordnce with the stndrd methods of the Americn Society for Testing of Mterils (ASTM) (Verl et l. ). Its surfce morphology ws chrcterized y scnning electron microscopy (SEM) (SEM-3 ASPEX) nd Fourier trnsform infrred (FTIR) spectroscopy efore nd fter the uptke of nd using SHIMADZU 8S Spectrometer for functionl groups etween nd 5 cm -. Adsorption experiments The dsorption of nd from queous solution y ctivted cron ws crried out using the tch technique. This involved the preprtion of ech dsorte solution with different initil concentrtions rnging from. to. mol L -. A known mss of dsorent rnging from to mg ws dded to the different 5 ml conicl flsks tht contined ml solution of ech dsorte nd the mixture ws gitted t rpm on the mechnicl shker for vrying times of 5 3 min nd t vrying tempertures of 3 C. Therefter, the mixture ws filtered nd the filtrte ws nlyzed y the potentiometric titrtion method. The quntity of ech dsorte dsored, Q e (g g - ), ws clculted using the eqution elow: Q e ¼ ðc o C e ÞV ; W where C o nd C e re the initil nd finl concentrtions (mol L - ), respectively, W is the dsorent dosge (g) nd V is the volume of the solution (ml). The percentge (%) dsored ws lso clculted using the eqution elow (Itodo et l. 9): %dsored ¼ C o C e C o : Results nd discussion The summry of the proximte nlysis of SB-AC is shown in Tle. Physicochemicl chrcteristics of SB-AC The FT-IR technique is n importnt tool to identify the chrcteristic functionl groups on the dsorent surfce which in some cses re responsile for the inding of the dsorte molecules (Slmn et l. ). The FT-IR spectr of the chemiclly ctivted cron from she utter seed shells efore nd fter dsorption re shown in Fig. c. The rod nds in the region 3., 337. nd 33.7 cm - efore nd fter dsorption of nd, respectively, were due to the hydroxyl stretching virtion, nd the nd in the region of 9.8 cm - in the cse of cetic cid ws due to CH symmetric nd symmetric stretching virtion. The stretching virtion of the C=O is t 7.77 cm - for. The shrp pek t 3.88 cm - efore dsorption ws slightly chnged to 359. cm - fter dsorption of oth nd which ws n evidence of the cronyl group. The stretching Tle Proximte nlysis of SB-AC Prmeter Vlue ph. Ash content (%).7 Moisture content (%). Bulk density (g cm -3 ).977 Iodine numer (mg g - )

3 Appl Wter Sci (7) 7: Fig. The FTIR spectrum of SB-AC efore dsorption. The FTIR spectrum of SB-AC fter dsorption of formic cid. c The FTIR spectrum of SB-AC fter dsorption of cetic cid 3

4 73 Appl Wter Sci (7) 7:77 73 virtion of the COO- group lies etween 5 nd cm -. The peks t 5.55,. nd.77 cm - indicte the stretching virtion of C O. Scnning electron microscopy (SEM) Scnning electron microscopy produces imges of smple y scnning it with focused em of electrons. The SEM imges of the prepred ctivted cron for oth efore nd fter dsorption of nd re shown in Fig.. Figure. shows the morphology of SB-AC efore dsorption. The cron reveled tht the surfce of SB-AC ws highly porous in nture nd would enhnce the dsorption of nd. The cron exhiited irregulr net-like structure, which implied the formtion of complete three-dimensionl porous inner structures consisting of rough surfce re. The pore development in the chr during pyrolysis ws lso importnt, s this would enhnce the surfce re nd pore volume of the ctivted cron y promoting the diffusion of the ctivting gent (HNO 3 ) molecules into the pores nd therey incresing the HNO 3 cron interction tht crete more pores on the surfce of ctivted cron. The development of these pores on the surfce of SB-AC could e the min fctor tht led to the high uptke of nd from queous solution. It is ovious in Fig., c tht the lrge pores on the surfce of ctivted cron efore dsorption were reduced fter dsorption of dsorte on the surfce of cron. This implied tht formic cid nd cetic cid were dsored onto the surfce of the prepred ctivted cron. Effect of initil concentrtion The initil concentrtion provides n importnt driving force to overcome ll mss trnsfer resistnce of nd etween the queous nd solid phse. In the present study, the effect of initil concentrtion of cids on the dsorption y SB-AC ws studied t temperture of 3 ± C,. g dsorent dose nd min contct time s clerly shown in Fig. 3,. The initil concentrtion of nd incresed from. to. mol L -. Figure 3 shows tht the uptke of dsorption incresed from. to.83 g g - with decrese in percentge from 5.3 to 7.87%. Figure. 3 shows tht the uptke of incresed from 55 to.53 g g - with n increse in the initil concentrtion up to mol L -. Then, the uptke decresed s the initil concentrtion further incresed. The mximum percentge dsorption Fig. SEM imge of SB-AC efore dsorption. SEM imge of SB-AC fter dsorption of. c SEM imge of SB-AC fter dsorption of lso incresed from to %. The reson my e tht there exists reduction in immedite solute dsorption owing to lck of ctive sites required for high initil concentrtion of cid. 3

5 Appl Wter Sci (7) 7: %dsored Ini l conc. (mol/l) 5 5 %dsored Qt(g/g) Qe (g/g). % Adsored. 3 Time (min).9 8 % dsored 5 3 %dsored 5 5 %dsored %dsored 8 %dsored.. Effect of contct time Ini l concentr on (mol/l) Fig. 3 Effect of the initil concentrtion of. Effect of initil concentrtion of Contct time is n importnt prmeter to determine the equilirium time of the dsorption process. The nd uptkes y SB-AC re shown in Fig., s function of vrying contct time from 5 to 3 min, t fixed initil concentrtion of. nd mol L - nd, respectively, 3 ± C temperture nd. g dsorent dose. It is ovious from Fig., tht the dsorption cpcity of incresed from to.738 g g - with incresing contct time. Lrge mounts of were removed in the first 3 min nd equilirium ws reched t min. After the equilirium, dsorption uptke did not increse significntly. Further increse in contct time did not increse the uptke due to deposition of on the ville dsorption site on the dsorent mteril. At this point, the mount of the desoring from the dsorent is in stte of dynmic equilirium with the mount of the eing dsored onto the dsorent. The time required to TTIME (min) Fig. Effect of contct time on the dsorption of. Effect of contct time on the dsorption of ttin this stte of equilirium is min, which is termed the optimum equilirium time, nd the mount of dsored t the equilirium time reflects the mximum dsorption cpcity of the dsorent under those operting conditions. Similrly, Fig. shows tht in the first min, the percentge removl of from queous solution incresed rpidly from to 5% nd decresed therefter which then incresed slowly until optimum time ws reched t min for the dsorte nd susequently ecme constnt. The result indictes tht the rte of dsorption of ecme higher during the initil time of dsorption nd then lowers in the ltter hlf of the process. This ws due to the nture of the dsorent nd the ville dsorption sites, which ffect the rte of dsorption of the dsorte. This difference in the rte of dsorption my e due to the fct tht initilly, ll dsorent sites were vcnt so the dsorption ws high. Lter, due to the decrese in the numer of dsorption sites on the dsorent, s well s concentrtion of dsortes in the 3

6 73 Appl Wter Sci (7) 7: %dsored 8 8 %dsored Qe (g/g) % dsored 8 %dsored Dose(g) 8 Temperture (⁰C) %dsored 8 %dsored %dsored %dsored.5..5 dose (g) 3 8 Temperture (C) Fig. 5 Effect of dsorent dose on the dsorption of. Effect of dsorent dose on the dsorption of solution, the dsorption ecme slow. Similr results hve een reported for the removl of croxylic cids on fly sh nd ctivted crons. Furthermore, the remining vcnt surfce sites were difficult to e occupied due to the repulsive forces, s well s the competition etween dsorte molecules on the dsorent surfce (Srivstv et l. ). Effect of dosge The effect of the dsorent dose determines the cpcity of the dsorent for given nd concentrtion. In this study, the effect of dsorent dose on the extent of solutes dsorption ws investigted y vrying the dosge from. to. g for SB-AC, t. nd mol L - fixed initil concentrtion of nd, respectively, min contct time nd 3 ± C temperture. Figure 5, shows the plots of the nd uptke ginst the quntity of the dsorent, respectively. nd uptke per unit mss decresed from.597 to.593 g g - nd Fig. Effect of temperture on the dsorption of. Effect of temperture on the dsorption of 3.73 to 9 g g -, respectively, with the increse in the dsorent dosge from. to. g. The reson for this trend my e ttriuted to the fct tht t high dsorent dosges, the ville nd molecules re not le to cover ll the ville sites on the dsorents, resulting in low uptke. Effect of temperture Temperture hs n importnt effect on the process of dsorption. The effect of temperture on the removl of nd from queous solution ws investigted y vrying the temperture rnging from 3 to C under optimized conditions of. g dsorent dose nd min contct time t fixed initil concentrtion of. mol L - for nd mol L - for. These re depicted in Fig.,. The dsorption of nd decresed from.553 to g g - nd from.538 to.785 g g -, respectively, s temperture incresed. This cn e explined y the exothermic spontneity of the dsorption process. The 3

7 Appl Wter Sci (7) 7: ttrctive forces etween the dsorent nd dsorte ions my hve een wekened to decresing the dsorption. At high temperture, the thickness of the oundry lyer is expected to decrese due to the incresed tendency of the ions to escpe from the surfce of the dsorent to the solution phse nd hence this is ound to weken the dsorption interctions etween the dsorent nd the dsortes. Adsorption isotherms The dsorption dt were nlyzed with some isotherms t the following experimentl conditions: C o = mol L - for nd. mol L - for, W =. g, temperture = 3 C nd min t rpm. The dsorption isotherm is fundmentl concept in dsorption science. It is the equilirium reltionship etween the mount of the sustnce dsored nd its concentrtion in the ulk fluid phse t constnt temperture. The primry experimentl informtion is usully mde up of these isotherms, commonly used s tool to distinguish mong different dsorents nd y this mens selecting the fitting ones for prticulr ppliction (Srivstv et l. ). Severl models re ville in literture to descrie the experimentl dt of the dsorption isotherm. In the current study, prmeter isotherms proposed y Freundlich, Lngmuir nd Temkin nd 3 prmeter isotherms proposed y Duinin Rdushkevitch (D R) were exmined with the equilirium dt otined from the experiments. The fitted prmeters for nd 3 prmeter models, s well s the correltion coefficient (R ), re summrized in Tle. Tle Prmeters of Freundlich, Lngmuir, Duinin Rdushkevich (D R) nd Temkin isotherm model for dsorption of nd onto SB-AC Isotherms Prmeters Vlues Freundlich n K f (mol g - ) R Lngmuir Q o (g g - ) K L (L mol - ) R.3 Temkin B (J mol - ).5. A T 5.77 R.3.93 D R B D (mol kj - ) q s (g g - ) E (kj mol - ).9.3 R.985 The high vlue of R (close or equl ) indictes the conformity mong experimentl dt with the model isotherm. The dsorption constnts of given isotherm llow, not only to evlute the dsorent properties of smple, ut lso to determine if dsorption is fvorle or not. The vlues of the constnts for Lngmuir, Freundlich, D R nd Temkin isotherm models t 35 K for the removl of nd onto SB-AC re presented in Tle ove. For the dsorption of onto SB-AC, the R vlue otined from the D R model ws the highest when compred with those of the Lngmuir, Freundlich nd Temkin models. Therefore, the D R model is the most suitle nd the order of fitting of the isotherms cn e rnked: D R [ Freundlich [ Temkin [ Lngmuir dsorption models. This is sign of strong interction etween nd SB-AC. Lngmuir isotherm model ppers to e firly good model for the dsorption of onto SB-AC due to its high regression coefficient (R = ). The constnt of Lngmuir (K L ) mesures the intensity of dsorption. In fct, the higher the K L vlue, the stronger is the ffinity etween the dsorte nd dsorent. The D R model gives informtion on the inding energies. The verge free energy, E, of molecule of dsorent expresses the energy relesed when molecule of dsorte psses from the solution into the dsorent (Kilic et l. ). It cn e oserved from Tle tht the sorption of onto SB-AC is governed y physicl dsorption mechnisms, since E \8 kj mol - (Ansri nd Mosyezdeh ), while tht of onto SB-AC is governed y chemicl dsorption mechnisms since E [ 8 kj mol - (Ansri nd Mosyezdeh ). Adsorption kinetics nd mechnism To study the kinetic models for the dsorption of nd on SB-AC, pseudo-first-order, pseudo-second-order nd Elovich models were used, while the dsorption mechnism ws evluted y the intrprticle diffusion model. The plots of ll the kinetic models used in this work re depicted in Fig. 7 nd their kinetic prmeters clculted from the slope nd intercept of ech plot nd summrized in Tle 3 under the following experimentl conditions: initil conc. of nd re. nd mol L - respectively, dsorent dose (W) =. g, temperture = 3 ± C nd contct time = min t rpm. It is evident from Tle 3 tht the pseudo-second-order kinetic model hs the highest regression correltion coefficient (R =.99) for nd R =.95 for when compred with those otined from the pseudo-first-order nd Elovich model. This implied tht the pseudo-secondorder model dequtely gve the est description of the 3

8 73 Appl Wter Sci (7) 7:77 73 log (Qe-Qt) Time (min) y = -.3x R² = y = -.x R² = -8 Tle 3 Pseudo-first-order, pseudo-second-order nd Elovich kinetic dt Kinetic model Prmeters Vlues Pseudo-first order K (min - ) Q e, cl. (g g - ).. R -8 Pseudo-second order K (g g - min - ) Q e, cl. (g g - ) R Elovich A.53 B R y =.3x R² =.99 dsorption kinetics of the two dsortes from the queous solution. It is lso pertinent to note the concordnce etween the experimentl nd theoreticl vlues for (.93 nd 33 g g - ) nd (.739 nd.738 g g - ), respectively. t/qt (min/g) c Qt(g/g) y =.x R² =.95 3 me (min) y =.53x R² = 8 y = x R² = Fig. 7 Pseudo-first-order (), Pseudo-second-order () nd Elovich (c) kinetic plots lnt Adsorption mechnism The Weer Morris intrprticle diffusion model ws used to determine whether the overll rte of dsorption ws controlled y intrprticle diffusion, i.e., the movement of the dsorte molecules into the interior of the dsorent prticles. A plot of q t versus t / gives liner reltionship s shown in Fig. 8. The vlue of intercept (C) nd the clculted vlue of intrprticle diffusion rte constnts (Kid) from the slope re summrized in Tle. The lrger intercept vlues suggest tht intrprticle diffusion hs lesser role to ply compred with surfce diffusion. The figure reveled tht two steps occur in the dsorption process. The shrply rising prt is the externl surfce dsorption stge, while the second liner prt is the grdul dsorption stge where intrprticle or pore diffusion is rte limiting. The high R vlues of the shrply rising prt suggest tht the externl surfce dsorption is the rte-limiting step. The devition of the lines from the origin nd the low R vlues of the grdul dsorption stge suggest tht intrprticle diffusion is not the sole rte-limiting step, s similr result ws erlier reported. This implied tht the externl surfce dsorption or instntneous dsorption stge occurred nd could e used to descrie the mechnism of the dsorption process (Theivrsu et l. ). 3

9 Appl Wter Sci (7) 7: qt (g/g) first step.9 y =.9x -. second step R² = y =.73 R² = #N/A First step Second step Adsorption thermodynmics y =.x -8 R² = 73 y = R² = 5E- 5 5 t/ Fig. 8 Intrprticle diffusion plot for () nd intrprticle diffusion plot for () The vlues of these prmeters (DH8, DS8, DG8) for the dsorption of dsortes ( nd ) onto dsorent re listed in Tle 5. The chnges in enthlpy (DH) nd entropy (DS) re negtive. This implies tht the rection ws exothermic, eing unfvorle t higher tempertures. This is cler from the effect of temperture results s shown in Fig. 9. Decrese in dsorption with increse in temperture hs een ttriuted to the wekening of lnk.5.5 dsorptive forces etween the ctive sites of the dsorent nd dsorte species nd lso etween djcent molecules on the dsored phse. The vlues of the dsorption entropy chnge (DS8) re negtive, which indicte tht the moility of dsortes on the surfce of the dsorent is more restricted s compred to those in solution. The negtive vlues of the dsorption free energy (DG8) in Tle 5 demonstrted tht the dsorption ws spontneous. The thermodynmic results otined in this study were in greement with those oserved y other reserchers (Mne et l. 7; Pn et l. 3). Conclusion y = 3.9x R² =.85.5 y = 9.x R² = Fig. 9 Vn t Hoff plots \T (K - ) The she utter seed shells ctivted cron (SB-AC) ws found to e n effective dsorent for the removl of formic cid nd cetic cid from queous solution. The study showed tht the initil concentrtion, contct time, the dsorent dose nd temperture of the solution influenced the dsorption process. Thermodynmic studies showed tht the dsorption process ws fesile, spontneous nd exothermic in nture. Lngmuir isotherm est fitted the dt for which confirmed the monolyer dsorption, Tle Intrprticle diffusion model Step Kid (mg g - min -/ ) C R Kid (mg g - min -/ ) C R Tle 5 The thermodynmic prmeters (DH, DS nd DG) evluted from the Vn t Hoff plot Adsorte DG (kj mol - ) DH (kj mol - ) DS (kj mol - K - ) 35 (K) 33 (K) 33 (K) 333 (K)

10 73 Appl Wter Sci (7) 7:77 73 while sorption of followed Duinin Rdushkevich (D R) model which gve informtion on inding energy. The dsorption of oth dsortes followed pseudo-secondorder rte kinetics. Therefore, the use of SB-AC s lowcost io-sorent is recommended for the dsorption of other croxylic cids from queous solution. Open Access This rticle is distriuted under the terms of the Cretive Commons Attriution. Interntionl License ( cretivecommons.org/licenses/y/./), which permits unrestricted use, distriution, nd reproduction in ny medium, provided you give pproprite credit to the originl uthor(s) nd the source, provide link to the Cretive Commons license, nd indicte if chnges were mde. References Adegoke HI, Adekol () Removl of phenol from queous solution y ctivted cron prepred from some griculturl mterils. Adv Nt Appl Sci (3):93 98 (ISSN ) Ansri R, Mosyezdeh Z () Removl of sic dye methylene lue from queous solutions using swdust nd swdust coted with polypyrrole. J Irn Chem Soc 7: Benkhedd J, Juert JN, Brth D, Perrin L, Bily M () Adsorption isotherms of m-xylene on ctivted cron: mesurements nd correltion with different models. J Chem Thermodyn 3: Freits AF, Mendes MF, Coelho GLV (7) Thermodynmic study of ftty cids dsorption on different dsorents. J Chem Thermodyn 39:7 37 Itodo AU, Adulrhmn FW, Hssn LG, Migndi SA, Itodo HU (9) Gs chromtogrphic prediction of equilirium phse Atrzine fter sorption onto derived ctivted cron. Int J Poult Sci 8():7 8 Knnn N, Xvier A () New comprtive mixed dsorents for the removl of cetic cid y dsorption form queous solutions. A Comp Study Toxicl Env Chem 79():95 Khh M, Ansri R (9) Activted chrcol: preprtion, chrcteriztion nd pplictions: review rticle. Int J Chem Tech Res ():859 8 Kilic M, Apydin-Vrol E, Putin AE () Adsorptive removl of phenol from queous solutions on ctivted cron prepred from tocco residues, equilirium, kinetics nd thermodynmics. J Hzrd Mter 89:397 3 Mne VS, Deo Mll I, Srivstv VC (7) Kinetic nd equilirium isotherm studies for the dsorptive removl of Brillint Green dye from queous solution y rice husk sh. J Env Mng 8():39 Nwnne JT, Igokwe PK () Mechnism of copper (II) removl from queous solution using ctivted cron prepred from different griculturl mterils. Int J Multidiscip Sci Eng 3(7): 5 [ISSN:5-757, Pn SC, Lin CC, Tseng DH (3) Reusing sewge sludge sh s dsorent for copper removl from wstewter. Resour Conserv Recy 39:79 9 Slmn JM, Njoku VO, Hmeed BH () Btch nd fixed-ed dsorption of,-dichloro phenoxycetic cid onto oil plm frond ctivted cron. Chem Eng J 7:33 Srivstv VC, Swmy MM, Mll ID, Prsd B, Mishr IM () Adsorptive removl of phenol y gsse fly sh nd ctivted cron equilirium, kinetics nd thermodynmics. Colloids Surf A 7:89 Theivrsu C, Mylsmy S, Sivkumr N () Coco shell s dsorent for the removl of methylene lue from queous solution, kinetic nd equilirium study. Univers J Environ Res Technol :7 78 Verl AW, Horsfll M, Verl EN, Spiff AI, Ekpete OA () Preprtion nd chrcteriztion of ctivted cron from fluted pumpkin (Telfiri occidentlis Hook.F) seed shell. Asin J Nt Appl Sci (3):39 5 3