Sorption mechanism of some heavy metal ions from aqueous waste solution by polyacrylamide ferric antimonite

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1 Trad Scinc Inc. ISSN : X Volum 6 Issu 2 ICAIJ, 6(2), 20 [82-90] Sorption mchanism of som havy mtal ions from aquous wast solution by polyacrylamid frric antimonit I.M.El-Naggar, E.A.Mowafy, Y.F.El-Aryan, M.G.Abd El-Wahd*,2 Atomic Enrgy Authority, Hot Labs. Cntr, P. No. 3759, Cairo, (EGYPT) 2 Chmistry Dpartmnt, Faculty of Scinc, Zagazig Univrsity, (EGYPT) mabdlamid@yahoo.com Rcivd: 25 th January, 20 ; Accptd: 5 th Fbruary, 20 ABSTRACT Incorporation of a polymr matrial into an inorganic ion xchangr provids a class of hybrid ion xchangrs with a good ion xchang capacity, high stability and high slctivity for havy mtals,w can s this probrtis in th prsnt study.th kintic of F (III), Pb (II), Cd (II), Cu (II), and Zn (II) ions on polyacrylamid frric antimonat has bn studid by applying th Nrnst-plank quation. Th rat of xchang is controlld by particl diffusion mchanism. Th physical thrmodynamic paramtrs such as activation nrgy and ntropy of activation hav bn valuatd and compard with othr inorganic and organic xchangrs. Th Langmuir and Frundlich modls hav bn applid to th adsorption isothrm and diffrnt constants wr gnratd. 20 Trad Scinc Inc. - INDIA KEYWORDS Synthsis; Polyacrylamid frric antimonit; Adsorption; Isothrm; Diffusion; Havy mtals. INTRODUCTION Th prsnc of havy mtal ions from th transition sris, viz, Cu, F, Ni, Pb, tc. in th nvironmnt is of major concrn du to thir toxicity to many lif forms. Unlik organic pollutants, th majority of which ar suscptibl to biological dgradation, mtal ions do not dgrad into harmlss nd products []. Havy mtals contamination xists in aquous wast stram from many industris such as mtal plating, mining, tannris, painting, car radiator manufacturing, as wll as agricultural sourcs whr frtilizrs and fungicidal spray intnsivly usd. Th rmoval of havy mtal in an ffctiv mannr from watr and wastwatr is, thus, cologically vry important. Thr ar many rportd and stablishd tchnologis for th rcovry of mtals from wastwatr, which includ chmical prcipitation [2], flotation [3], lctrolytic rcovry, mmbran sparation [4] and activatd carbon adsorption [5,6]. In rcnt yars, th sarch for Anw class of high prformanc and high functional organic-inorganic composit ion-xchangrs wr dvlopd by th incorporation of organic conducting polymrs into inorganic prcipitats [7-9]. Ths matrials wr found slctiv for havy toxic mtal ions and utilizd for analysis of watr pollution such matrials hav a grat dal of attntion bcaus of thir spcial mchanical and chmical stabilitis [0-2]. Th nwly dvlopd composit offrd a high capacity and fastr sorption kintics for th mtal ions such as F (III), Pb (II), Cd (II), Cu (II), and Zn (II) ions.

2 ICAIJ, 6(2) 20 Matrials MATERIALS AND METHODS All chmicals usd in this work wr of analytical grad and usd without furthr purification. Distilld watr was mployd for all glasswar and in prparing aquous solution. Apparatus Inductiv Coupld plasma spctromtr (ICPS- 7500) shimadzu corporation, Kyoto, japan and atomic absorption flam mission spctrophotomtr (AA- 670F) shimadzu corporation, Kyoto, japan. th ph masurmnts wr prformd by ph mtr and th total xprimntal rror was about 3%. Procdurs Watr washing of ion xchingr Th polyacrylamid frric antimonat composit wr washd with doubl distlld watr to rmov all fin particls. th drid matrial at 50 o C was sivd to obtain diffrnt msh sizs of mm. Th sivd matral was usd for furthr xprimntal work. PREPARATION OF POLYACRYLAMIDE FERRIC ANTIMONATE M.G.Abd El-Wahd t al. 83 a prcipitat of frric antimonat to polyacrylamid with stirrr by using magntic stirrr to obtain homognous prcipitat. Th prcipitats wr lft to ag in th mothr liquor ovrnight, th prcipitat washd by distilld watr svral tims. Th suprnatant liquid was dcantd and th gl was filtrd using a cntrifug (about 0 4 rpm) and drid at 50± o C. Th product was crashd and sivd to obtain diffrnt msh sizs of mm. Th wight loss of polyacrylamid frric antimonat in th diffrnt forms such as H(I), Pb (II), F (III), Cd (II), Cu (II) and Zn (II) ions wr dtrmind by using thrmal analysis tchniqu (TG and DTA). Th wight loss of polyacrylamid frric antimonat in H(I), Pb (II), F (III), Cd (II), Cu (II) and Zn (II) ions at 000 o C ar 34.9%, 7.33%, 9.8%, 2.55%, 2.22% and 2.33% w/w, rspctivly. CHEMICAL STABILITY Chmical stability of polyacrylamid frric antimonat ion xchangrs wr studid in watr, nitric and hydrochloric acid [,2,3,4,5 and 6M], as wll as in potassium and sodium hydroxid (0., M) by mixing 50mg of ion xchangr sampls and 50 ml of th dsird solution with intrmittnt shaking for thr wks at 25 ± o C. Prparation of polyacrylamid Polyacrylamid was prpard by mixing qual volum of 20% acrylamid prpard in distilld watr with 0. M potassium prsulfat (K 2 S 2 O 8 ) prpard in M HCl, a viscous solution was obtaind by hating th mixtur gntly at 70±5 0 C with continuous stirring. Prparation of frric antimonat Frric antimonat prpard from 0.5 M of frric chlorid dissolvd in distilld watr and adding th sam volum of 0.5 M antimony mtal dissolvd in aqua rgia slowly with constant stirring using a magntic stirrr at a tmpratur of 70±5 0 C. Th rsulting solution was prcipitat by using ammonia solution drop by drop until th ph about 0.3. Rd brown prcipitat has bn formd. Prparation of polyacrylamid frric antimonat Polyacrylamid frric antimonat formd by adding CAPACITIES OF POLYACRYLAMIDE FERRIC ANTIMONATE FOR pb 2+, F 3+, Cd 2+, Zn 2+ AND Cu 2+ IONS Capacitis wr dtrmind by rpatd batch quilibration of 0.M mtal chlorid solution solutions (pb 2+, F 3+, Cd 2+, Zn 2+ and Cu 2+ ) with th solid matrial in V/m ratio 50ml/g was carrid out for th capacity valuation. Th mixtur was shakd in a shakr thrmostat at 25± o C. Aftr ovr night standing th solid was sparatd and th concntration of th mtal ions was masurd by using Inductiv Coupld plasma spctromtr (ICPS-7500) and atomic absorption flam mission spctrophotomtr (AA- 670F). Th procdur was rpatd until no furthr absorption of cations occurrd. Th capacitis wr calculatd from th following quation: %uptak Capacity inmg / g C V 0 Z 00 m ()

3 84 Sorption mchanism of. som havy mtal ions whr C o is th initial concntration of th ion in solution, V is th solution volum, m is th wight of th xchangr, Z is th valnc of th xchangd ions. KINETIC STUDIES Th kintic analysis of th adsorption procss for Pb (II), F (III), Cd (II), Cu (II) and Zn (II) ions on polyacrylamid frric antimonat was carrid out by mixing of th xchangr with mtal ions solution (ph qual to 4.55, 4.06, 4.32, 4. and 4.3 for Pb (II), F (III), Cd (II), Cu (II) and Zn (II) ions, rspctivly) with a V/m ratio of 00 ml/g in a shakr thrmostat at 25± o C. th solution was sparatd at diffrnt tim intrvals and analyzd to dtrmin th mtal ion concntration in solution by using ICPS-7500 for Pb (II), F (III), Cd (II), Cu (II) and Zn (II) ions. th xtnt of sorption was dtrmind. All th xprimnts wr carrid out at 25, 45 and 65± o C and th rsults agrd to ±3% for all raction tims. Sorption % = [(A i -A f )/A i ] x 00 (2) Whr A i and A f ar th initial and final concntration of th mtal ions in solution. ADSORPTION ISOTHERM Th quilibrium adsorption isothrms ar on of th promising data to undrstand th mchanism of th adsorption. Various isothrm quations ar wll known and two diffrnt isothrms ar slctd in this study, which ar th Langmuir and Frundlich isothrms. Th sorption isothrm is don by th gradual incras of th concntration of th sorbat in solution and masuring th amount sorbd at ach quilibrium concntration. Th dgr of sorption should b a function of th concntration of th sorbat only. Th sorption isothrms for Pb (II), F (III), Cd (II), Cu (II) and Zn (II) ions wr dtrmind at th concntration rang (5x M) at ph = 4 and at a V/m ratio of 00 ml/g.th xprimnts wr carrid out at 25, 45 and 65± o C in a shakr thrmostat. Analysis Pb (II), F (III), Cd (II), Cu (II) and Zn (II) ions wr masurd using ICPS-7500 and atomic absorption flam mission spctrophotomtr (AA- 670F). RESULTS AND DISCUSSION ICAIJ, 6(2) 20 In this work w attmpt to synthsiz a high chmical stabl composit matrial with high slctivity for som havy mtals. Th ion xchang capacity of polyacrylamid frric antimonat for Pb (II), F (III), Cd (II), Cu (II) and Zn (II) ions wr invstigatd and th data ar rprsntd in TABLE. TABLE indicatd that th affinity squnc for all cations is pb 2+ >F 3+ > Cu 2+ >Cd 2+ >Zn 2+ This trnd may b du to th strongr lctrostatic intraction rducing its mobility in th xchangr. Th lctrongativity of pb 2+ >F 3+, Cu 2+, Cd 2+ and Zn 2+ and may b du to th ionic radii of F 3+ < Cu 2+ < Cd 2+ < Zn 2+. Also, may b owing to th hydratd radius according to th fact that on incrasing atomic numbr dcrasing th hydratd ionic radii [3]. TABLE : Capacitis of polyacrylamid frric antimonit for pb 2+, Cd 2+, F 3+, Cu 2+ and Zn 2+ ions on Mtals Pb 2+ F 3+ Cu 2+ Cd 2+ Zn 2+ Capacity of mq/g Th rat of ion xchang raction is govrnd by th slowst stp which may b diffusion in th liquid surrounding th particl of th xchangr (film diffusion control) or diffusion insid th xchangr particls (particl diffusion mchanism) and or th ion xchang procss whn th xchanging ions form strong complxs with th functional groups of th xchangr (chmical control) [4]. Th xprimntal conditions of th prsnt work wr st to study th particl diffusion mchanism only as a limitd batch tchniqu. Bsid, stirring and mchanical shaking did not nhanc th rat of xchang. Th quation usd for valuating th kintic paramtrs is dvlopd by Boyd [5] as follows: 6 F (3) 2 2 / r 2 n Di 2 2 n n Whr F: is th fractional attainmnt of quilibrium, n: is an intgr numbr, D i : is th ffctiv diffusion cofficint of th xchanging insid th particls, r: is th particl radius. This quation was improvd by Richnbrg [6] and can b usd if th rat dtrmining stp is diffusion through th xchangr particls. Thus, quation (3) may b writtn in th following form:

4 ICAIJ, 6(2) 20 6 n 2 Bt F xp (4) 2 2 n n B = ð 2 Di/r 2 Whr Bt is a mathmatical function of F. Richnbrg has tabulatd th valus of Bt. Corrsponding to ach valu of fractional attain of quilibrium from quation (4). For a particl diffusion mchanism, th rlation btwn Bt vs. t should b giving a straight lin. Whn F (t) is lss than 0.4, quation (4) is approximatd to th simpl form [5]. F(t) = 6/r (D i /ð) /2 (5) Which hold to a good approximation. Thrfor, a plot of F (t) against th squar root of th contact tim must giv a straight lin passing through th origin in th rang in which F (t) is lss than 0.4. Th ffct of concntration on th rat of xchang of th mtal ion on polyacrylamid frric antimonat at 25± o C dmonstrats that th initial rat of xchang is indpndnt of concntration. From th rlation btwn th fractional attainmnt of quilibrium (F) and tim for Pb (II), F (III), Cd (II), Cu (II) and Zn (II) ions, it is vidnt that th rat of xchang is indpndnt on th mtal ion concntration. Ths rsults agrd with that rportd for tin antimonat and hydrous titanium dioxid [7]. Th ffct of particl sizs on th rat of xchang of Pb (II), F (III), Cd (II), Cu (II) and Zn (II) ions on polyacrylamid frric animonat was studid at 25± o C. Straight lins passing through th origin ar obtaind, which had takn as indication of a particl diffusion mchanism as shown in (Figur, w took th rsults and figurs of lad as xampl for th sak of brvity), a rlation btwn F and Bt against tim. Similar trnd was obsrvd by (El-Naggar t al., 2007; Abou- Msalam and El-Naggar, 2003) [8,3]. This figur shows that th xchang rat of Pb (II), F (III), Cd (II), Cu (II) and Zn (II) ions incrass with dcrasing th particl sizs which is agrmnt with th conditions of particl diffusion mchanism. Dtaild rsults and figurs of th othr mtal ions ar not givn hr for th sak of brvity. A plot of B against /r 2 Figur 2 for all mtal Pb (II), F (III), Cd (II), Cu (II) and Zn (II) ions studid ar a straight lin, indicating that th rat of xchang is invrsly proportional to th squar of th particl M.G.Abd El-Wahd t al. 85 radius, which is anothr proof of particl diffusion control [9]. Data in TABLE 2 shown that, D i valus ar gnrally slightly incrasd with incrasing th particl sizs. Th small incras of D i with incras of par- Figur : Plots of F and Bt against tim for xchang of Pb(II) on polyacrylamid frric antimonat at diffrnt partical diamtrs. Figur 2 : Plots of B against /r 2 for adsorption of F(III), Pb(II), Cd(II), Cu(II), and Zn(II) ions on polyacrylamid frric antimonat. TABLE 2 : Valus of diffusion cofficint of F 3+, Pb 2+, Cd 2+, Cu 2+, and Zn 2+ on polyacrylamid frric antimonat, at diffrnt particl diamtrs at 25± o C. Particl Di, cm 2 s - x0 8 diamtr (±0.02 mm) Pb(II) F(III) Cd(II) Cu(II) Zn(II)

5 86 Sorption mchanism of. som havy mtal ions D o = 2.72 (KTd 2 /h) xp (ÄS*/R) (7) Whr, K is th Boltzmann constant, T is th absolut tmpratur; d is th avrag distanc btwn two succssiv positions in th procss of diffusion and it takn as qual to 5Å, h is Plank constant and R is th gas constant. It is intrsting to compar th valus of activation nrgis for all mtal ions studid rportd hrin TABLE 3 with othr valus of activation nrgis which hav bn obsrvd for th xchang of othr mtal ions on polypyrrol/polyantimonic acid and acrylamid crium(iv) phosphat, whr as th activation nrgy valus for Mg(II), Ca(II), Sr(II), Ba(II), Cu(II), Ni(II), Zn(II)and Mn(II) to b 4., 5.4, 5.6, 5.2, 9.23, 8.47, 8.72 and 6.44 KJmol - rspctivly, th activation nrgy for Mg(II), Ca(II), Sr(II) and Ba(II) on acrylamid crium(iv) phosphat to b 9.95, 9.5, 8.89 and 6.03 KJmol - rspctivly [7], th valus of activation nrgy obsrvd on acrylonitril basd crium(iv) phosphat for Mg(II), Ca(II), Sr(II), Ba(II), Mn(II), Co(II), Cu(II) and Zn(II) wr found to b 4.88,.76, 0.32, 8.62, 3.85, 9.93, 9.53 and.36 kj mol - rspctivly, th valus of activation nrgy for Zn(II), Cd(II), Hg(II), La(III) and Th(IIII) on frric antimonat wr found to b 7.2, 2., 23.0, 5.3 and 3.5 kj mol - rspctivly [2] and th valus of activation nrgy for th cobalt on tin antimonat to b 9.5 kjmol - rspctivly [22]. Th activation nrgy for Pb (II), F (III), Cd (II), Cu (II) and Zn (II) ions studticl siz may b attributd to th larg particls ar lss compact [8]. Th plots of Bt and F against t for th xchang of Pb (II), F (III), Cd (II), Cu (II) and Zn (II) ions at diffrnt raction tmpraturs (25, 45 and 65 ± o C) on polyacrylamid frric antimonat ar prsntd in (Figur 3, w took th rsults and figurs of lad as xampl for th sak of brvity). It was found that straight lins passing through th origin. This confirms that th phnomnon is particl diffusion controlld, and th rat of xchang incrass by incrasing th raction tmpraturs from 25 to 65 ± o C. Figur 4 shows that, th valu of D i incrass with incrasing th hat- Figur 3 : Plots of F and Bt against tim for xchang of Pb(II) on polyacrylamid frric antimonat at diffrnt raction tmpraturs. Figur 4 : Arrhnius Plots (log D i ) against /T for th xchang F(III), Pb(II), Cd(II), Cu(II), and Zn(II) ions on poly acrylamid frric antimonat at diffrnt raction tmpraturs. ICAIJ, 6(2) 20 ing tmpraturs from 25 to 65 o C for all mtal ions studid, as illustratd in TABLE 3. Th valus of ffctiv diffusion cofficint (Di) hav bn calculatd and summariz in TABLE 3. TABLE 3 shows that th apprciabl incras of diffusion cofficint of F 3+, Pb 2+, Cd 2+, Cu 2+, and Zn 2+ ions with an incras in raction tmpratur. Whn log D i is plottd against /T for xchang of Pb (II), F (III), Cd (II), Cu (II) and Zn (II) ions Figur 4, straight lins ar obtaind for th abov fiv havy mtals ions, nabling th calculation of nrgy of activation (E a ) and th slf diffusion cofficint (D o ) from Arrhnius quation as follows. D i = D o xp (-Ea/RT) (6) Howvr, th ntropy of activation (ÄS*) can b calculatd from D o by substituting in th quation proposd by Barrr [20].

6 ICAIJ, 6(2) 20 id on polyacrylamid frric antimonat taks th ordr: F(III) (9.4) > Cu(II) (5.77) > Zn(II) (4.56) > Cd(II) (4.37)> Pb(II) (2.86) Th rlativly small activation nrgy valus (E a ) obtaind in TABLE 3, for Pb (II), F (III), Cd (II), Cu (II) and Zn (II) ions, indicatd that th rat of xchang is particl diffusion mchanism [23]. On othr word, ths valus of activation nrgy ar rlativly small compard to that rportd for othr composit, organic and inorganic xchangrs which confirm th particl diffusion mchanism. TABLE 3 : Thrmodynamic paramtrs for th xchang of F 3+, Pb 2+, Cd 2+, Cu 2+, and Zn 2+ on polyacrylamid frric antimonat, at diffrnt raction tmpraturs. Mtal ion Raction tmpratur D i x0 8 D o x0 5 cm 2 s - cm 2 s - E a KJ mol - M.G.Abd El-Wahd t al. 87 ÄS* J mol - k Pb(II) Cd(II) ntropy chang incrass in ordr. Pb(II)< Cd(II)< Zn(II)<Cu(II)< F(III) thus showing a maximum ntropy chang bing for F(III) xchang. Th ngativ valus of th ntropy of activation indicat th prsnc of mor activ sits in its structur and suggst that no significant structural chang occurrd in polyacrylamid frric antimonat Zn(II) Figur 5 : Th corrlation btwn S* and Ea for F(III), Pb(II), Cd(II), Cu(II), and Zn(II) ions on polyacrylamid frric antimonat at 25 C Cu(II) F(III) Th valus of diffusion cofficint for all mtals tak th ordr. Cu(II) > Zn(II) > Cd(II)> F(III) >Pb(II), this may b attributd to th dcras in th lctrostatic intraction of th countr ions with th xchang sits, hydratd ionic radius and lctrongativity of th mtals ion studid. Th rlativly small activation nrgy valus which ar givn in TABLE 3, for Pb (II), F (III), Cd (II), Cu (II) and Zn (II) ions suggst that th rat of xchang is particl diffusion mchanism. Th valus of D o, Ea and ÄS* thus obtaind ar summarizd in TABLE 3. Ths rsults show that thr is a linar rlation btwn th Ea and ÄS* valu Figur 5, but th incras in ionic radii of th mtal ion lads to dcrass th nrgy of activation [7] Figur 6, ths rsults also indicat that th Figur 6 : Th corrlation btwn ionic radii and Ea for F(III), Pb(II), Cd(II), Cu(II), and Zn(II) ions on polyacrylamid frric antimonat at 25 C ADSORPTION ISOTHERM Th Langmuir adsorption isothrm assums that adsorption taks plac at spcific homognous sits within th adsorbnt and has found succssful applications in

7 88 Sorption mchanism of. som havy mtal ions many adsorption procsss of monolayr adsorption. For th cas of adsorption in solution, th quation is rprsntd by th following [24]. C q C qmaxk L q (8) max Whr q (mol g - )is th adsorption capacity for Pb (II), F (III), Cd (II), Cu (II) and Zn (II) ions on th adsorbnt at th quilibrium, C (mol dm -3 )is th quilibrium ions concntration in th solution, q max is th monolayr adsorption capacity of th adsorbnt, and K L is th Langmuir adsorption constant. Th plots of C /q vs. C for th adsorption of pb(ii) ion onto composit Figur 7 giv a straight lin of th slop, and intrcpt, q k max L. q max log q ICAIJ, 6(2) 20 log k F log C (9) n Whr K F (dm 3 g - ) and n (dimnsionlss) ar Frundlich adsorption isothrm constants, bing indicativ of th xtnt of th adsorption and th dgr of nonlinarity btwn solution concntration and adsorption, rspctivly. Figur 7 : Plots of C /q against C for th xchang of pb(ii) on polyacrylamid frric antimonat at diffrnt raction tmpraturs. W took th rsults and figurs of lad as xampl for th sak of brvity. Th Frundlich isothrm is an mpirical quation mployd to dscrib htrognous systms Th plot of ln K L vs. /T for Pb (II), F (III), Cd (II), Cu (II) and Zn (II) ions is givn in Figur 8. Accordingly th valus of ÄH at saturation ar calculatd for Pb (II), F (III), Cd (II), Cu (II) and Zn (II) ions on polyacrylamid frric antimonat and rprsntd in th TABLE 4. Ths valus indicat th xothrmic bhavior of polyacrylamid frric antimonat. Th linarizd form of th Frundlich isothrm quation is [25]. Figur 8 : Langmuir adsorption isothrm for th sorption of F(III), Pb(II), Cd(II), Cu(II), and Zn(II) ions on polyacrylamid frric antimonat at diffrnt raction tmpraturs. TABLE 4 : Isothrm paramtrs for adsorption of Pb (II), F (III), Cd (II), Cu (II) and Zn (II) ions on polyacrylamid frric antimonat. Elmnts Th fr nrgy G o associatd to th adsorption procss and thy wr dtrmind by using following quation. (0) o G RTlnK L Langmuir Frundlich H KJ/mol G o KJ/mol K F n Pb F Cu Cd Zn Th rsults ar givn in TABLE 4 show that th chang of fr nrgy for physisorption is gnrally btwn - 20 and 0 kj mol -, th physisorption togthr with chmisorption is at th rang of -20 to -80 kj mol - and chmisorptions is at a rang of -80 to -400 kj mol -[26]. As can b sn from TABLE 4, th ovrall standard fr nrgy changs during th adsorption procss wr ngativ for th xprimntal rang of tmpraturs,

8 ICAIJ, 6(2) 20 corrsponding to a spontanous and a boundary of physisorption procss of Pb (II), F (III), Cd (II), Cu (II) and Zn (II) ions on poly acrylamid frric antimonat. Th ngativ valu of th nthalpy chang of Pb(II) ion indicats that xothrmic bhavior, and th positiv valu of th nthalpy chang indicats that th adsorption procss is ndothrmic and this valu also indicats that th adsorption follows a physisorption mchanism in natur involving wak forcs of attraction btwn th adsorbd of (Pb (II), F (III), Cd (II), Cu (II) and Zn (II) ions) and composit, thrby dmonstrating that th adsorption procss is stabl nrgtically [27]. Th Frundlich constant n is a masur of th dviation from linarity of th adsorption. If a valu for n is blow to unity, this implis that adsorption procss is govrn by a chmical mchanism, but a valu for n is abov to unity, adsorption is favorabl a physical procss. Th K F and n wr calculatd from th slops of th Frundlich plots as shown in (Figur 9, w took th rsults and figurs of lad as xampl for th sak of brvity) and wr found to b ( ) and ( ) rspctivly. Th magnituds of K F and n show asy sparation of havy mtal ion from wastwatr and high adsorption capacity [28]. Th valu of n, which is rlatd to th distribution of bondd ions on th sorbnt surfac, rprsnt bnficial adsorption if is btwn and 0 [29,30]. Th valus of n at quilibrium ar rprsnting favorabl adsorption at studid tmpraturs and thrfor this would sm to suggst that a physical mchanism, which is rfrrd th adsorption bond bcoms wak [3] and conductd with van dr Figur 9 : Frundlich adsorption isothrm for th sorption of F(III), Pb(II), Cd(II), Cu(II), and Zn(II) ions on polyacrylamid frric antimonat at diffrnt raction tmpraturs M.G.Abd El-Wahd t al. 89 Waals forcs. TABLE 4 givs th isothrm paramtrs for both Langmuir and Frundlich isothrms. From ths paramtrs of th adsorption isothrm, it was notd that th Frundlich isothrm modl xhibits bttr data than th Langmuir isothrm modl. CONCLUSION Th prsnt study shows that polyacrylamid frric antimonat is an ffctiv adsorbnt for th rmoval of Pb (II), F (III), Cd (II), Cu (II) and Zn (II) ions from aquous solutions. Th following rsults hav bn obtaind: - polyacrylamid frric antimonat has a good ion xchang capacity, high stability and high slctivity for Pb (II) and F (III) than Cd (II), Cu (II) and Zn (II) ions. 2- th adsorption follows a physisorption mchanism in natur involving wak forcs of attraction btwn th adsorbd of Pb (II), F (III), Cd (II), Cu (II) and Zn (II) ions and polyacrylamid frric antimonit.. 3- it was notd that th Frundlich isothrm modl xhibits bttr data than th Langmuir isothrm modl. REFERENCES [] K.V.Gupta, M.Gupta, S.Sharma; Watr Rs., 35, (200). [2] O.J.Esalah, M.E.Wbr, J.H.Vra; Can.J.Chm. Eng., 78, (2000). [3] A.I.Zouboulis, K.A.Matis, B.G.Lanara, C.L.Nskovic; Sp.Sci.Tchnol., 32, (997). [4] L.Cant, M.Ilpid, P.Sat; Sp.Sci.Tchnol., 37, (2002). [5] V.Ravindran, M.R.Stvns, B.N.Badriyha, M.Pirbazari; AICHE J., 45, (999). [6] C.A.Tols, W.E.Marshall; Sp.Sci.Tchnol., 37, (2002). [7] A.A.Khan, M.M.Alam, Inamuddin, F.Mohammad; Elctroanal.Chm., 572, (2004). [8] A.A.Khan, M.M.Alam, F.Mohammad; Elctrochim. Acta, 48, (2003). [9] A.A.Khan, M.M.Alam, Inamuddin; Matr.Rs. Bull., 40, (2004).

9 90 Sorption mchanism of. som havy mtal ions [0] U.Schubrt, N.Husing, A.Lornz; Chm.Matr., 7, (995). [] N.K.Raman, M.T.Andrson, C.J.Brinkr; Chm. Matr., 8, (996). [2] J.Wn, G.L.Wilkns; Chm.Matr., 8, (996). [3] M.M.Abou-Msalam, I.M.El-Naggar; Colloids & Surfacs A: Physicochm.Eng.Aspcts, 25, (2003). [4] I.M.El-Naggar, E.A.Mowafy, Y.F.El-Aryan, M.G.Abd El-Wahd; Solid Stat Ionics, 78, (2007). [5] G.E.Boyd, A.W.Admson, L.S.Myrs; J.Am.Chm. Soc., 69, (947). [6] D.J.Richnbrg; Am.Chm.Soc., 75, (953). [7] I.M.El-Naggar, M.A.El-Absy; J.Radioanal.Nucl. Chm., 57, (992). [8] I.M.El-Naggar, E.A.Mowafy, E.A.Abdl-Galil; Colloids & Surfacs A: Physicochm.Eng.Aspcts, 307, (2007). [9] I.M.El-Naggar, E.S.Zakaria, S.A.Shady, H.F.Aly; Solid Stat Ionics, 22, (999). ICAIJ, 6(2) 20 [20] R.M.Barrr, R.F.Bartholomw, L.V.C.Rss; Phys. Chm.Solids, 2, 2-24 (96). [2] K.G.Varshny, N.Tayal, U.Gupta; Colloids and Surfacs B: Biointrfacs, 28, -6 (2003). [22] K.G.Varshny, N.Tayal; Colloids and Surfacs A: Physicochmical and Enginring Aspcts, 62, (2000). [23] J.P.Rawat, J.P.Singh; J.Inorg.Nucl.Chm., 40, (978). [24] I.Langmuir; J.Am Chm.Soc., 40, (96). [25] H.M.F.Frundlich; Z.Phys.Chm., 57, (906). [26] M.J.Jaycock, G.D.Parfitt; Chmistry of Intrfacs, Ellis Horwood Ltd., Onichstr, (98). [27] Y.Yu, Y.Y.Zhuang, Z.H.Wang; J.Colloid Intrf.Sci., 242, (200). [28] N.Saifuddin, A.Z.Raziah; Journal of Applid Scincs Rsarch, 3, (2007). [29] K.Kadirvlu, C.Namasivayam; Environmntal Tchnology, 2, (2000). [30] M.Solnr, S.Tunali, A.Safa Ozcan, A.Ozcan, T.Gdikby; Dsalination, 223, (2008). [3] J.-Q.Jiang, C.Coopr, S.Ouki; Chmosphr, 47, 7-76 (2002).