Biosorption of Cadmium (II) from Aqueous Solutions by Prunus Avium Leaves

Transcription

1 Amrican Journal of Environmntal Enginring 0, (5: 3-7 DOI: 0.593/j.aj Biosorption of Cadmium (II from Aquous Solutions by Prunus Avium Lavs Nidá M. Salm, Ahlam M. Farhan, Akl M. Awwad 3,* Faculty of Agricultur, Jordan Univrsity, Amman, Jordan Dpartmnt of Chmistry, Collg of Scinc for womn, Univrsity of Baghdad, Baghdad, Iraq 3 Royal Scintific Socity, Princss Sumaya Univrsity for Tchnology, El Hassan Scinc City, Amman, Jordan Abstract A nw biosorbnt from Prunus avium (swt chrry lavs was usd to rmov cadmium(ii from aquous solutions. Th biosorption of cadmium(ii was found to b dpndnt on solution ph, initial mtal ion concntrations, biosorbnt dos, and contact tim. Th xprimntal quilibrium biosorption data wr analyzd by two widly usd two-paramtrs, Langmuir and Frundlich isothrm modls. Th Langmuir modl gav a bttr fit than th Frundlich modl. Th kintic studis indicatd that th biosorption procss of th cadmium ions followd wll psudo-scond-ordr modl. It was concludd that Prunus avium lavs powdr can b usd as an ffctiv, low cost, and nvironmntally frindly biosorbnt for th rmoval of Cd(II ions from aquous solution. Kywords Biosorption, Prunus avium Lavs, Cad miu m(ii Ions, BiosorptionIsothrms, Kintic. Introduction Th major sourcs of Cd(II rlas into th nvironmnt by wast strams ar lctroplating, smlting, alloy manufacturing, pigmnts, plastic, battry, mining and rfining procsss. Cadmium is on of th toxic havy mtals, which is rgardd as an lmnt of high toxicity. Diffrnt mthods hav bn usd on cadmium contnt rduction from watr and industrial wast such as chmicalprcip itati on, ion xchang, mmbran filtration, lctrolytic mthods, rvrs osmosis, solvnt xtraction, and activatd carbon adsorption[]. Ths convntional tchniqus can rduc cadmium ions, but thy do not appar to b highly ffctiv du to th limitations in th ph rang as wll as th high matrial and oprational costs. Diffrnt biosorbntmatrial s hav bn invstigatd for rmoval of cadmium ions from aquous solutions such as plant matrials lik what straw[], agricultural wast biomass [3], ric husk[4], orang pl[5], nut husk[6], sugar bt pulp[7], orang wast[8], coconut shll[9], junipr bark and wood[0] and what stm[].in rcnt yars, considrabl attntion has bn focusd on th rmoval of cadmium ions from aquous solution using adsorbnts drivd from low-cost tr lavs such as loquat lavs [], sidiumguajava avs[3], maiz laf[4], ulmus lavs[5], Scolymus * Corrsponding author: amawwad000@yahoo.com (Akl M. Awwad Publishd onlin at Copyright 0 Scintific & Acadmic Publishing. All Rights Rsrvd hispanicus.[6], Ulmus carpinifolia and Fraxinus xclsior tr lavs[7], In th prsnt work, W hav studid th potntial of cadmium(ii ions biosorption on Prunus avium (swt chrry co ming fro m P. avium tr lavs. Rsults from this study can b usd to assss th utility of P. avium lavs powdr for cadmium(ii ions rmoval from watr and industrial wastwatrs.. Matrials and Mthods.. Ads or bnt Th raw Prunus avium (swt chrry lavs wr collct d from a local plantation. Th lavs wr thoroughly rinsd with watr to rmov dust and solubl matrials. Thn it was allowd to dry at room tmpratur. Th drid lavs was groundd to a fin powdr in a grinding mill (Rtsch RM 00 and sivd to gt siz fraction < 44 µm, and thn drid in an ovn at 60 o C for 4 h... Matrials All th chmicals usd wr of analytical ragnt (AR grad. Stock solutions of 000 mg/l of cad miu m(ii ionswr prpard from nitrats of cadmium which was purchasd from Fluka AG using doubl distilld watr. Dsird tst solutions of cadmium ions wr prpard using appropriat subsqunt dilutions of th stock solution. Th rang of concntrations of cadmium ions prpard from standard solution varis btwn 0 and 00 mg/l. Bfo r mixing th adsorbnt, th ph of ach tst solution was

2 4 Nidá M. Salm t al.: Biosorption of Cadmium (II from Aquous Solutions by Prunus avium Lavs adjustd to th rquird valu with 0. M NaOH or 0. M HCl..3. Anal ysis Th concntrations of Cd(II ions in th solutions bfor and aftr quilibrium wr dtrmind by AAS6300 Atomic absorption spctromtr (Shimadzu, Japan. Th ph of th solution was masurd with a WTW ph mtr using a combind glass lctrod. Fourir Transform Infrard Spctroscopy, FTIR (IR Prstig-, Shimadzu, Japan was usd to idntify th diffrnt chmical functional groups prsnt in th P. avium lavs powdr. FTIR analyss also usd to dtrmin th functional groups which ar rsponsibl for th cadmium binding with P. avium lavs powdr. Th analysis was carrid out uing KBr and th spctral rang varying from 4000 to 400 cm..4. Biosorpti onexprimnts Batch biosorption xprimnts wr conductd by mixing biosorbnt with cadmium ion solutions with dsirdconcnt ration in 50 ml glass flask. Th glass flasks wr stopprd during th quilibration priod and placd on a tmpratur controlld shakr at a spd 0 r/min. Th ffct of ph on th quilibrium biosorption of Cd(II was invstigatd by mixing, Th amount of biosorption was calculatd basd on th diffrnc btwn th initial (C o, mg/l and final concntration (C, mg/l in vry flask, as follows: Co C = xv ( M whr q is th mtal uptak capacity (mg/g, V th volum of th mtal solution in th flask (L and M is th dry mass of biosorbnt (g. Prcnt rmoval (% R of cadmium ions was calculatd from th following quation: Co C % R = x00 ( C o with P. avium lavs powdr. Th pak at 635cm indicats th fingrprint rgion of CO, C O and O H groups, which xist as functional groups of P. Avium and shifting of this pak to 63cm, indicatd involvmnt of ths groups in cadmium binding. Th band at 377 cm - corrsponding of C-O strtching was shiftd to 404 cm -. Th rgion btwn 84 and 000 cm - is th fingrprint rgion, OH, and C-H bnding vibration and C-O strtching vibration absorption bands. Th intns band at 09 cm - can b assignd to th C-O of alcohols and carboxylic acids. Th shift of th pak from 09 to 00 cm also suggsts th involvmnt of C O group in binding Cd(II. Th shifts in th absorption paks gnrally obsrvd indicat th xistnc of a cadmium binding procss taking plac on th surfac of th P. avium lavs powdr. Fi gur. FTIR of P. avium lavs powdr 3. Rsults and Discussion 3.. FT-IR Analysis To invstigat th functional groups of P. avium and cadmium loadd on P. avium, a FT-IR study was carrid out and th spctra ar shown in Figurs.. and. Th P. avium lavs display a numbr of absorption paks, rflcting thir complx natur. A strong and broad pak at 3356cm rsults du to th strtching of th N H bond of amino groups and indicativ of bondd hydroxyl group of alcohols and phnols. A chang in pak position to 3375 cm - in th spctrum of th cadmium loadd P. avium, Fig., indicats th binding of cadmium with amino and/or hydroxyl groups. Th absorption paks at 939 cm and 893cm could b assignd to CH strtching vibrations of CH 3 and CH functional groups. Th shouldr pak in pur P. avium lavs powdr at 70 cm - is shiftd to low frquncy 696 cm - du to th involvmnt of carbonyl CO group from carboxylic acids in th biosorption procss of cadmium ions Fi gur. FT IR of P. avium lavs powdr loadd with cadmium 3.. Effct of PH Th ph has bn idntifid as on of th most important paramtr that is ffctiv on mtal sorption. It is dirctly rlatd with comptition ability of hydrogn ions with mtal ions to activ sits on th biosorbnt surfac. Th ffct of ph on th biosorption of Cd(II ions onto P.avium lavs powdr was studid at ph Th maximu m biosorpti on was obsrvd at ph 6.5 for Cd(II. Thrfor, th rmaining all biosorption xprimnts wr carrid out at this ph valus. Th biosorption mchanisms on th P.avium lavs powdr surfac rflct th natur of th physicochmical intraction of th solution. At highly acidic ph (ph <.0, th ovrall surfac charg on th

3 Amrican Journal of Environmntal Enginring 0, (5: activ sits bcam positiv and mtal cations and protons complt for binding sits on cll wall, which rsults in lowr uptak of mtal. Th biosorbnt surfac was mor ngativly chargd as th ph solution incrasd from.0 to 6.0. Th functional groups of th P. avium lavs powdr wr mor dprotonatd and thus availabl for th mtal ions. Dcras in biosorption yild at highr ph (ph > 6 is not only rlatd th formation of solubl hydroxylatd complxs of th mtal ions (cadmium ions in th form of Cd(OH but also to th ionizd natur of th cll wall surfac of th bark powdr undr th studid ph Effct of Contact Ti m Th rat of biosorption is important for dsigning batch biosorption xprimnts. Thrfor, th ffct of contact tim on th biosorption of d Cd(II was invstigatd. Th biosorption yild of Cd(II incrasd considrably until th contact tim rachd 0 min. Furthr incras in contact tim did not nhanc th biosorption, so, th optimum conta ct tim was slctd as 0 min for furthr xprimnts 3.4. Effct of Adsorbnt Dos on Biosorption Th biosorbnt dosag is an important paramtr bcaus this dtrmins th capacity of a biosorbnt for a givn initial concntration. Th biosorption fficincy for Cd(II ions as a function of biosorbnt dosag was invstigatd. Th prcntag of th mtal biosorption stply incrass with th biosorbnt loading up to 0.5 g/0. L. This rsult can b xplaind by th fact that th biosorption sits rmain unsaturatd during th biosorption raction whras th numbr of sits availabl for biosorption sit incrass by incrasing th biosorbnt dos. Th maximum biosorptio n 94.44% for Cd(II was attaind at biosorbnt dosag, 0.5 g/0. L. Thrfor, th optimum biosorbnt dosag was takn as 0.5 g/0. L for furthr xprimnts Biosorpti on Isothrms An adsorption isothrm dscris th fraction of sorbat molculs that ar partitiond btwn liquid and solid phass at quilibrium. Two isothrm modls wr tstd: Frundlich isothrm Th Frundlich isothrm modl is th wll known arlist rlationship dscribing th adsorption procss. This modl applis to adsorption on htrognous surfacs with th intraction btwn adsorbd molculs and th application of th Frundlich quation also suggsts that sorption nrgy xponntially dcrass on compltion of th sorption cntrs of an adsorbnt. This isothrm is an mpirical quation and can b mployd to dscrib htrognous systms and is xprssd as follows in linar form[8]: log = log K F + logc (3 n whr K F is th Frundlich constant rlatd to th bonding nrgy. /n is th htrognity factor and n (g/l is a masur of th dviation from linarity of adsorption.frundlich quilibrium constants wr dtrmind from th plot of log q vrsus log C, Figur 3 on th basis of th linar of Frundlich quation (3.Th n valu indicats th dgr of non-linarity btwn solution concntration and adsorption as follows: if n=, thn adsorption is linar; if n<, thn adsorption is a chmical procss; if n>, thn adsorption is a physical procss. Th n valu in Frundlich quation was found to b.5 for P. avium, Tabl. Sinc n li btwn and 0, this indicat th physical biosorption of cadmium (II onto P. avium. Th valus of rgrssion cofficints R ar rgardd as a masur of goodnss of fit of th xprimntal data to th isothrm modls. log Fi gur 3. Frundlich isothrm for Cd (II biosorption onto P. avium lavs powdr at 303 K Lang mu ir isothrm Th Langmuir isothrm assums monolayr adsorption on a uniform surfac with a finit numbr of adsorption sits[9]. Onc a sit is filld, no furthr sorption can tak plac at that sit. As such th surfac will vntually rach a saturation point whr th maximum adsorption of th surfac will b achivd. Th linar form of th Langmuir isothrm modl is dscribd as: C = + C (4 K Lqmax qmax whr K L is th Langmuir constant rlatd to th nrgy of adsorption and qmax is th maximum adsorption capacity (mg/g. Valus of Langmuir paramtrs qmax and K L wr calculatd from th slop and intrcpt of th linar plot of C / vrsus C as shown in Figur 4. Valus of qmax, K L and rgrssion cofficint R ar listd in Tabl. Ths valus for P. avium biosorbnt indicatd that Langmuir modl dscribs th biosorption phnomna favaroubl. Th ssntial charactristics of th Langmuir isothrm paramtrs can b usd to prdict th affinity btwn th sorbat and sorbnt using sparation factor or dimnsionlss quilibriu m paramtr, R L xprssd as in th following quation: R L log C ( + K C = (5 whr K L is th Langmuir constant and C o is th initial concntration of cadmium (II ions. Th valu of sparation paramtr R L provids important information about th natur of adsorption. Th valu of R L indicatd th typ of L o

4 6 Nidá M. Salm t al.: Biosorption of Cadmium (II from Aquous Solutions by Prunus avium Lavs Langmuir isothrm to b irrvrsibl (R L =0, favorabl (0<R L <, linar (R L = or unfavorabl (R L >. Th R L was found to b for concntration of 0 40 mg/l of Cd(II. Thy ar in th rang of 0- which indicats th favourabl biosorption. c//(g/l Fi gur 4. Langmuir isothrm for Cd (II biosorption onto P. avium lavs powdr at 303 K Tabl. Frundlich and Langmuir constants `for Cd(II ions biosorpt ion by P. avium at 303 K Frundlich isothrm K F n R Langmuir isothrm K L q ma x R Biosorpti on Ki ntics C (mg/l Paramtrs from two kintic modls, psudo first-ordr and psudo scond-ordr wr fit to xprimntal data to xamin th biosorption kintics of cadmium (II uptak by P. avium lavs powdr Psudo First-Ordr Kintics Th psudo-first ordr quation of Lagrgrn[0] is gnrally xprssd as follows: dqt = k( (6 dt Whr and qt ar th sorption capacitis at quilibrium and at tim t, rspctivly (mg/g and K is th rat constant of psudo-first ordr sorption, (/min. Aftr intgration and applying boundary conditions, q t = 0 to q t = q t at t = 0 to t = t ; th intgratd form of quation (6 bcoms: k log( = log t (7.303 Th quation applicabl to xprimntal rsults gnrally diffrs fro m a tru first ordr quation in two ways: th paramtr k ( - q t dos not rprsnt th numbr of availabl sits; and th paramtr log q is an adjustabl paramtr which is oftn not found qual to th intrcpt of a plot of log (q q t against t, whras in a tru first ordr sorption raction log should b qual to th intrcpt of log(q q t against t. In ordr to fit quation (7 to xprim ntal data, th quilibrium sorption capacity, q must b known. In many cass is unknown and as chmisorption tnds to bcom un masurably slow, th amount sorbd is still significantly smallr than th quilibrium amount. In most cass in th litratur, th psudo-first ordr quation of Lagrgrn dos not fit wll for th whol rang of contact tim and is gnrally applicabl ovr th initial 0 to 60 minuts of th sorption procss. Furthrmor, on has to find som mans of xtrapolating th xprimntal data to t =, on trating as an adjustabl paramtr to b dtrmind by trial and rror. For this rason, it is thrfor ncssary to us trial and rror to obtain th quilibrium sorption capacity, in ordr to analyz th psudo-first ordr modl kintics. Th psudo first ordr rat constant can b obtaind from th slop of plot btwn log (q q t against tim, t. Figur 5 shows th Lagrgrn psudo-first ordr kintic plot for th adsorption of cadmium ions onto P. avium lavs powdr. Th calculatd valus and thir corrsponding linar rgrss ion corrlation cofficint valus ar shown in Tabl. Th linar rgrssion corrlation cofficint valu found ,which shows that this modl cannot b applid to prdict th adsorption kintic modl. log(-qt t (min Fi gur 5. Psudo-first ordr kintic modl for Cd (II biosorption onto P. avium lavs powdr at 303 K Psudo-Scond Ordr Kintics Th psudo scond-ordr rat xprssion, which has bn applid for analyzing chmisorption kintics rat[0] is xprssd as: dqt = K ( (8 dt Whr q and q t ar th sorption capacity at quilibrium and at tim t, rspctivly (mg/g and k is th rat constant of psudo-scond ordr sorption, (g/mg min. For th boundary conditions to q t = 0 to q t = q t at t = 0 to t = t; ; th intgratd form of quation (8 bcoms: t q = + t (9 k q q Whr t is th contact tim (min, q (mg/g and q t (mg/g ar th amount of th solut adsorbd at quilibrium and at any tim, t. If psudo-scond ordr kintics is applicabl, th plot of t/q t vrsus t of quation (9 should giv a linar rlationship, from which q and K can b dtrmind fro m th slop and intrcpt of th plot, Fig. 6. Th psudo-scond o rdr rat constant K, th calculatd q valu and th corr sponding linar rgrssion corrlation cofficint valu ar givn in Tabl. At all initial mtal concntrations, th linar rgrssion corrlation cofficint R valus wr highr. Th highr valus confirm that th adsorption data ar wll rprsntd by psudo-scond ordr kintics.

5 Amrican Journal of Environmntal Enginring 0, (5: t/qt(min/mg/g Fi gur 6. Psudo-scond ordr kintic modl for Cd (II biosorption onto P. avium lavs powdr at 303 K Tabl. Biosorption kintic paramtrs for Cadmium (II ions by P. avium lavs at 303 K Psudo-first ordr K q (mg/g R Psudo-scond ordr K q (mg/g R 8.8E Conclusions Th potntial of P. avium lavs powdr for th rmoval of Cd(II ions fro m aquous solutions and wastwatr was dpndnt on biosorption procss such as ph, initial mtal ions concntration, biosorbnt dos, and contact tim,. Th Langmuir and Frundlich biosorption isothrms wr dmo nstratd to provid bst corrlation for th biosorption of Cd(II ions onto P. avium lavs powdr. Th kintic rsults providd th bst corrlation of th xprimntal data of biosorption of cadmium ions onto P. avium lavs powdr by psudo scond-ordr quation. it can b concludd that sinc th P. avium lavs ar an asily, locally availab l, lo w-cost adsorbnt and has a considrabl high biosorption capacity, it may b tratd as an altrnativ adsorbnt for tratmnt of wastwatr containing cadmium (II ions. ACKNOWLEDGMENTS Authors ar thankful for Royal Scintific Socity, Jordan Univrsity and Baghdad Univrsity for providing th ncssary facilitis to carry out this work. REFERENCES Tim (t [] Tobin, J.M Roux, J.C., 998.Mucorbiosorbnt for chromium rmoval from tanning fflunts, Watr Rs. 3: [] Dang, V.B.H., Doan, H.D., Dang-Vu, T., Lohi, A., 009. Equilibrium and kintics of biosorption of cadmium(ii and coppr(ii ions by what straw. Biors. Tchnol. 00: 9. [3] Garg, U., Kaur, M.P., Jawa, G.K., Sud, D., Garg, V.K., Rmoval of cadmium (II from aquous solutions by adsorption on 59 agricultural wast biomass. J. Hazard. Matr. 54: [4] Kumar, U., Bandyopadhyay, M., 006. Sorption of cadmium from 537 aquous solution using prtratd ric husk. Biorsour. Tchnol : [5] Li, X., Tang, Y., Xuan, Z., Liu, Y., Fang Luo, F., 007. Study on th prparation of orang pl cllulos adsorbnts and biosorption of Cd+ from aquous solution. Sp. Purif. Tchnol. 55: [6] Okiimn, F.E., Okuundla, E.V., Ogbifun, D.E., 99. Sorption of cadmium and lad ions on modifid ground nut husks. J. Chm. Tchnol. Biotchnol. 5: [7] Phlivan, E., Yanik, B.H., Ahmtli, G., Phlivan, M., 008. Equilibrium isothrm studis for th uptak of cadmium and lad ions onto sugar bt pulp. Biorsour. Tchnol. 99: [8] Prz-Marin, A.B., Zapata, V.M., Ortuno, J.F., Aguilar, M., Saz, J., Llorns, M., 007. Rmoval of cadmium from aquous solutions by adsorption onto orang wast. J. Hazard. Matr. 39: 3. [9] Pino, G.H., Souza d Msquita, L.M., Torm, M.L., Pinto, G.A.S., 006. Biosorption of cadmium by grn coconut shll powdr. Minr. Eng [0] Shin, E.W., Karthikyan, K.G., Mandla, A., Tshabalala, M.A., 007. Adsorption mchanism of cadmium on junipr bark and wood. Biorsour. Tchnol. 98: [] Tan, G.Q., Xiao, D., 009. Adsorption of cadmium ion from aquous solution by ground what stms. J. Hazard. Matr. 64: [] Awwad, A.M., Salm, N. M., 0. Biosorption of Coppr (II and lad (II ions from aquous solutions by Modifid Loquat (Eriobotrya japonica lavs (MLL, J. of Chm. Eng. and Matr. Sci., 3: 7-7. [3] Varma, D.S.N.R., Srinivas, Ch., Nagamani, Ch., Prmsagar, T., Rajskhar, M., 00. Studis on biosorption of cadmium on Psidiumguajava lavs powdr using statistical xprimntal dsign. J. Chm. Pharm. Rs. : [4] Babarind, N.A.A., ibabalola, J.O., Sanni, S.O., 007. Isothrm and thrmodynamic studis of th biosorption of Cd(II from solution by maiz laf. Intrnational Journal of Physical Scincs Vol. : [5] Mahvi, A.H., Gholami, F., Nazmara, S., 008. Cadmium biosorption from wastwatr by ulmus lavs and thir ash. Eur. J. Scint. Rs. 3: [6] Barka, N., Abdnnouri, M., Boussaoud, A., EL Makhfouk, M., 00.Biosorption charactristics of Cadmium(II onto Scolymushispanicus L. as low-costnatural biosorbnt. Dsalination 58: [7] Sangi, M.R., Shahmoradi, A., JavadZolgharnin, J., Azimi, G.H., zaghorbandoost, M., 008. Rmoval and rcovry of havy mtals from aquous solution using Ulmus carpinifolia and Fraxinus xclsior tr lavs. Journal of Hazardous Matrials 55: [8] Frundlich, H., 906. Ubbr di adsorption in liosungn, Z. Phys. Chm. 57: [9] Langmuir, I., 98. Th adsorption of gass on plan surfacs of glass, mica and platinium, J. Amr. Chm. Soc. 40: [0] Lagrgrn, S., 998. Zurthori dr sognanntn adsorption glostrstoff. KungligaSvnskaVtnskapasakadmins, Handlingar 4: 39.