STUDY AND SIMULATION OF COMPETITIVE SORPTION OF 2,4-D AND PHENOL ON WASTE TYRE RUBBER GRANULES

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1 STUDY AND SIMULATION OF COMPETITIVE SORPTION OF 2,4-D AND PHENOL ON WASTE TYRE RUBBER GRANULES Md. Jahir Bin Alam, R. K. Chowdhuary, M. M. Hasan, A. Huda 2 and S. Sobhan Dpartmnt of Civil and Environmntal Enginring, Shahjalal Univrsity of Scinc and Tchnology, Sylht, Bangladsh 2 Graduat studnt, Grndich Univrsity, UK jahiralam@yahoo.com ABSTRACT Batch study for sorption of 2,4-D and phnol on wast tyr rubbr granuls (WTRG) wr carrid out for chcking fasibility of rubbr granuls as adsorbnt. Aftr minuts of raction tim, it was vidnt that th kintics profils gradually bcam horizontal indicating th final quilibrium. Th rmoval of 2,4-D and phnol byond 2 was vry low. Th rmoval was 83.2% and 87% in 2hr at.75mg/l and.4mg/l, rspctivly for 2,4-D. Th rmoval was 53.2% and 58.7% in 2hr at.75 mg/l and.4mg/l, rspctivly for phnol. It is clar from th analysis that Frundlich modl fittd wll with th xprimntal data and prdictd amount of wll in bi-solut. Kywords: sorption, phnol, rubbr, granuls, wast, adsorbnt. INTRODUCTION 2, 4-D and phnol ar found in th watr bodis. Rmoval of ths compounds is ssntial bcaus prsnc of phnolic compounds causs odor. Morovr thy ar toxic. Many rsarchrs trid to rmov ths pollutants from watr nvironmnt. Kannan and Karuppasamy (998) usd ta powdr and saw dust as adsorbnts for th rmoval of phnyl actic acid. Thy found it as an ffctiv adsorbnt with contact tim 8min. Singh and Mishra (99) rportd that imprgnatd saw dust was found fficint adsorbnt for rmoval of phnolic compound. Singh t al. (994) rportd that for imprngnatd flyash, th maximum rmoval of phnols was found at a ph 6.5 and a contact tim 2min. Th objctiv of this study was to xamin th us of rubbr granuls as an adsorbnt for rmoval of 2,4- D and phnol for singl and bio-solut aquous solutions. In this work quilibrium adsorption data, ffct of ph on th adsorption of phnol and 2,4-D individually and combind from aquous solutions on rubbr granuls. Furthr an attmpt is mad to valuat th paramtrs of isothrms from xprimntal data on singl solut adsorption and th paramtrs ar usd to prdict th adsorption from bio-solutions assuming idal conditions. MATERIALS AND METHODS Sorbnt Th wast tyr rubbr granuls wr providd by Rubbr Tchnology Cntr, IIT, Kharagpur, India and sivd to siz rang 5-3µm. Rubbr granuls wr washd out distilld watr for rmoval of forign matrials kping th mixtur in plastic bottl at 5rpm in a mchanical shakr for 3hrs. Aftr washing, it was drid for 2 days in sunlight. Thn it was ovn drid at 5-6 C for 5hrs to rmov th moistur prsnt in th pors. It was thn coold to room tmpratur, sivd to its original siz, and stord in airtight bottls. Charactristics of rubbr granuls sorbnt Tyrs ar gnrally composd of diffrnt typs of rubbr such as txtil cords, fabric blts, and vulcanizd rubbr. Styrn Butadin Rubbr is th widly usd polymr by th tyr industris. Carbon black, zinc oxid, natural rubbr, sulfur tc. ar also addd. Carbon black is usd to strngthn th rubbr (Kim t al., 997). Bulk spcific gravity and porosity of rubbr granuls wr masurd using standard mthods (APHA- AWWA-WPCF, 989). Th surfac ara was masurd by nitrogn adsorption mthod (BET 624, Micro-mritics, Grmany). Scanning Elctron Microscop studis of wast tyr rubbr granuls wr carrid out using SEM (LEO S-44, Grman). It showd th prsnc of iron compounds, zinc, silica tc. in th rubbr granuls sampls. Zn contnt was masurd by atomic absorption spctrophotomtr (AAS 67, Shimazu, Japan). For this Zn was brought to solution form by kping 2 g Rubbr granuls in : HNO 3 solution for 24hrs and aftr filtration, th filtrat was dilutd 25 tims for th masurmnt of Zn. It was found to b 2.3%. Th IR spctrum of rubbr granuls was carrid out using IR spctrophotomtr (Prkin-Elmr, UK). Th pak at 3438cm - in th IR spctrum indicatd th prsnc of - COOH or -OH group. Th pak at 232cm - indicatd th prsnc of C N, C C or C=C or isocyanats group. Th othr bonding prsnc in tyr rubbr granuls wr >C=O, C-H bonding and C-O. Thrmo Gravimtric Analysis (TGA) was conductd for chmical analysis of wast tyr rubbr granuls using TGA (DT-4, Shimazu, Japan). Th physical and chmical charactristics of wast tyr rubbr granuls as dtrmind by abov tsts ar dscribd in Tabl- blow: Tabl-. Physical and chmical charactristics of wast tyr rubbr granuls. Paramtrs Valus Bulk spcific gravity.284 g/cm 3 Porosity

2 Surfac ara gm/m 2 Carbon black 48-52%* Polymr matrix 3-33%* Othr matrials Silica, Zinc oxid, Iron tc.** Ash contnt 2-3% As dtrmind by * TGA tst, ** SEM tst. Sourc: Alam, 22. Kintic study A known of singl and bio-solut aquous mixtur of phnol and 2,4-D was prpard by dissolving rquird amount of soluts. Equilibrium adsorption data wr obtaind by contacting a known wight of rubbr granuls (5g/l) with ml of solution of rquird initial in stopprd Erlnmyr flasks. Th flasks wr shakn for 3-4hr in a shakr in a thrmostatic bath at 25 C. Th sampls wr filtrd through a Whatman No. 5 filtr papr to liminat any fin particls. Thn th s wr dtrmind by masuring absorbanc. RESULTS AND DISCUSSION Rmoval kintics of hrbicids on rubbr granuls Th rmoval kintics of 2,4-D and phnol by th rubbr granuls for diffrnt s ar shown in Figur-. It may b sn that mor than 6% of th pollutants wr sorbd within 6 minuts of raction tim and this was du to th availability of th numbr of fr sits within rubbr granuls and a high gradint btwn th solution and th solid phas. Th attainmnt of th quilibrium tim for sorption of hrbicids or organic psticids in compltly mixd batch ractor (CMBR) was found in th rang of fw minuts to svral hours by many rsarchrs (Aly and Faust, 965; Tszos and Wang, 99). Aftr minuts of raction tim, it was vidnt that th kintics profils gradually bcam horizontal indicating th final quilibrium. Th rmoval of 2, 4-D and phnol byond 2 was vry low. Th rmoval was 83.2% and 87% in 2hr at.75mg/l and.4mg/l, rspctivly for 2,4-D For 2,4-D For 2,4-D For Phnol For Phnol Concntration (mg/l) Tim(min) Figur-. Chang of with tim for 2,4-D and phnol sorption on rubbr granuls with initial of.75mg/l and.4mg/l. Th rmoval was 53.2% and 58.7% in 2hr at.75mg/l and.4mg/l, rspctivly for phnol. Isothrm study Th quilibrium sorption data of phnol and 2,4- D on rubbr granuls at 25 C wr obtaind and graphically prsntd in Figur-. An obsrvation of th rsults indicats that th amount of solut adsorbd incras with incras in th initial of th solut. Furthr th xtnt of adsorption of 2,4-D is mor than that of phnol. Th bio-solut quilibrium adsorption is prsntd in Figur-2. From th plot it can b obsrvd that th xtnt of adsorption of on solut dcrass with incras in starting of othr solut. But th dcras in th cas of phnol adsorption in th prsnc 2,4-D rubbr granuls systm Tmpratur: 27 C Siz:.5-.3 mm Dos: 23 gm/l of 2,4-D than 2,4-D adsorption in th prsnc of phnol. Furthr th amount of phnol and 2,4-D adsorbd from bio-solut systm is lss than th sum of componnts adsorbd individually at th sam. This may b du to comptition btwn th soluts for activ sit. 46

3 .8 Concntration (mg/l) For 2,4-D in prsnc of phnol.5mg/ l For 2,4-D in prsnc of phnol.25mg/l For Phnol in prsnc of 2,4-D.5mg/ l For Phnol in prsnc of 2,4-D.25mg/l Tim (min) Figur- 2. Comptitiv sorption of 2,4-D and Phnol in prsnc of Phnol and 2,4-D, rspctivly. For matrial to b assssd as adsorbnt, quilibrium studis hav to b conductd. In adsorption procss, particular volum or wight of solids is addd to th solution containing a crtain of pollutant. Whn th adsorbnt coms in contact with th solution, th adsorbat gts accumulatd on th surfac of th adsorbnt. In this procss, a dynamic quilibrium would b stablishd which mans th migration of adsorbat from solution to th solids gt countr balancd by th adsorbat migration from solid to solution. At this position no significant rmoval of adsorbat is xpctd furthr. Equilibrium.-stag at which all potntial sits of th adsorbnt rach th quilibrium, q, th adsorbnt is said to b xhaustd and th capacity at this point is calld maximum adsorptiv capacity, Q max. To assss th capacity of any adsorbnts saturation adsorptiv capacity is th appropriat paramtr to b considrd. Exprimntal isothrms ar usful for dscribing sorption capacity to valuat of th fficacy of an adsorbnt. Morovr th isothrm is ssntial in prdictiv modling procdur for analysis and dsign of sorption systms (Vnkobachar, 99; Das and Bandyopadhyay, 99). Langmuir modl assums that th sorption nrgy is constant and indpndnt of surfac covrag. Equilibrium studis wr carrid out and th xprimntal isothrm was dvlopd. log q = log K f + n logc Scrning studis rvald that Langmuir modl (Figurs 3 and 4) has shown a poor corrlation with data followd by Frundlich modl (Figurs 5 and 6). Th quilibrium sorption data of singl soluts ar fittd to Langmuir (q i = a i C i, /(+b i C i, ) and Frundlich sorption isothrms (q i = ki(ci, ) n i and th valus of th paramtrs a i, b i, k i and n i ar valuatd using last-squar procdur. Th paramtrs ar usd to prdict adsorption from bio-solut solution basd on Frundlich and Langmuir multi-solut adsorption modls. Tabls 2 and 3 show th prdictd valu of amount of 2,4-D in prsnc of phnol with xprimntal data and prdictd valu of amount of phnol in prsnc of 2,4-D with xprimntal valu, rspctivly. Figur-7 shows th rlationship btwn prdictd valus of amount of 2,4-D in prsnc of phnol by Frundlich modl with xprimntal data sts. Th data sts indicat that th modl is capabl to rprsnt th rsults. q n n, [ ( q q2 )] q + q2 k n2 C = +..( bi-solut Frundlich modl for 2,4-D) q2 n2 n2 2, [ ( q q2 )] q + q2 k 2 n C = + (bi-solut Frundlich modl for phnol) q = ac, + ( b C + b C ). (bi-solut Langmuir modl for 2,4-D), 2 2, 47

4 q 2 = a2c2, + ( b C + b C )... (bi-solut Langmuir modl for phnol), 2 2, C /q y = x R 2 = Figur-3. Application of Langmuir modl for 2,4-D sorption C C /q y = x R 2 = Figur-4. Application of Langmuir modl for phnol sorption C. r =.932 Y = X log q. E-3.. log C Figur-5. Application of Frundlich modl for 2,4-D sorption 48

5 Log q = x Log q (mg/g).. log C (m g/l) Initial of 2,4-D Figur-6. Application of Frundlich modl for phnol sorption Tabl-2. Prdictd valu of amount of 2,4-D in prsnc of phnol. Phnol Equilibrium Prdictd amount of pollutants by Frnundlich Prdictd amount of pollutants by Langmuir Exprimntal valu Initial of phnol Tabl-3. Prdictd valu of amount of phnol in prsnc of 2,4-D Prdictd Prdictd 2,4-D Equilibrium amount of amount of pollutants by pollutants by Frnundlich Langmuir Exprimntal valu

6 .45 Exprimntal valu R 2 = Prdictd valu Figur-7. Rlationship btwn prdictd q by Frundlich modl for 2,4-D in th prsnc of phnol. Many rsarchrs (Loganathan, 977; Vnkobachar, 99 and Alam, 22) showd that th prsnc of othr pollutants hav influnc on th sorption of any pollutants. Alam (22) showd th ffct of prsnc of atrazin on 2,4-D sorption on rubbr granuls. It was found from his studis that prdiction of sorption for bisolut cas is vry complx and propr kintic studis ar ssntial for prdiction. Sorption on rubbr granuls of 2,4-D and phnol may follow th scond-dgr kintic raction rat, so prdiction is smi- quantativ in natur. Similar rsult was showd by th study of sorption of 2,4- D and atrazin on rubbr granuls and havy mtals on wast biomass (Alam, 22; Osman, 995). CONCLUSION This study was carrid out to xamin th us of rubbr granuls as an adsorbnt for rmoval of 2, 4-D and phnol for singl and bio-solut aquous solutions. It was clar from kintic study that th rmoval of 2,4-D and phnol byond 2 was vry low. So, 2 minuts was slctd as quilibrium tim for both th pollutants. Th rmoval was 83.2% and 87% in 2hr at.75 mg/l and.4mg/l, rspctivly for 2,4-D. Th rmoval was 53.2% and 58.7% in 2hr at.75mg/l and.4mg/l, rspctivly for phnol. Th prdictd valus of q ar prsntd in th rsult and discussion sction with xprimntal data. Th data indicats that both modls wr capabl of rproducing rsults approximatly. Btwn two modls, Frundlich modl fittd wll with th xprimntal data and prdictd amount of wll in bi-solut. It may b du to bttr fitting of xprimntal data with Frundlich modl for singl solut cas. REFERENCES Alam, J. B. 22. Rmoval of hrbicids from watr nvironmnt and its managmnt. Ph.D Thsis. Dpartmnt of Civil Enginring, Indian Institut of Tchnology, Kharagpur, India. Aly, O.M. and Faust, S.D Rmoval of 2,4- Dichlorophnoxy Actic Acid drivativs from natural watrs. J. Amrican Watr Works Association. Vol. 3(2): APHA-AWWA-WPCF Standard mthods for th xamination of watr and wastwatr. Amrican Public Halth Association, Nw York. Das, N.C. and Bandyopadhyay, M. 99. Rmoval of lad by vrmiculit mdium. Applid Clay Sci.. Vol. 6: Hlffrich, F Ion Exchang. McGraw-Hill, Nw York, USA. Loganathan, P., Burau, R.G. and Furstnau, D.W Influnc of ph on th sorption of Co 2+, Zn 2+ and Ca 2+ by a hydrous mangans oxid. Solid sci. Soc. Am. J. Vol. 4: Kim J.Y., Park J.K. and Edil, T.B Sorption of organic compounds in th aquous phas onto tyr rubbr. J. Environmntal Enginring, ASCE. Vol. 23(9): Kannan, N. and Karuppasamy, K Low cost adsorbnts for th rmoval of phnolic acid from aquous solution. Indian J. of Environ. Protction. Vol. 8(9): 683. Osman, G. M Rmoval of havy mtal from watr nvironmnt. Ph. D Thsis. Dpartmnt of Civil Enginring, Indian Institut of Tchnology, Kharagpur, India. 5

7 Snoyink, V.L. and Jnkins, D. 98. Watr Chmistry. John Wily and Sons Inc., Nw York, USA. Singh, D. K. and Mishra, A. 99. Rmoval of phnolic compounds from watr by using chmically tratd saw dust. Indian J. of Halth. Vol. 32(4):345. Singh, B. K., Misha, N. M. and Rawat, N. S Sorption charactristics of phnols on flyash and imprgnatd flyash. Indian J. Environ. Halth. Vol. 36():. Tszos, M. and Wang, X. 99. Study on th kintics of hazardous pollutants adsorption and dsorption by biomass: Mchanistic considrations. J. Chm. Tch. Biotch. Vol. 34(2): Vnkobachar, C. 99. Mtal rmoval by wast biomass to upgrad wastwatr tratmnt plants. Wat Sci. Tch. Vol. 22(7-8):