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TAP CHI HOA HOC T 49(4) 489 493 THANG 8 NAM 2011 ANH HU''''6''''NG CUA MOT S6 Y^U T 6 D^N QUA TRJNH XU'''' LY CONGO D6 B A N G PHU''''aNG PHAP FENTON DIEN HOA Pham Thi Minh'''', Nguyen Thj Le Hien^ Dinh Thj Mai Than[.]
TAP CHI HOA HOC T 49(4) 489-493 THANG NAM 2011 ANH HU'6'NG CUA MOT S6 Y^U T D^N QUA TRJNH XU' LY CONGO D6 B A N G PHU'aNG PHAP FENTON DIEN HOA Pham Thi Minh', Nguyen Thj Le Hien^ Dinh Thj Mai Thanh', Thai Hoang' Vi^n Ky thudt nhiqt d&i ~ Vi^n Khoa hgc vd Cdng ngh? Viqt Nam ^Chi nhdnh Vien Ddu Viet Nam - Trung tdm Ifng dung vd Chuyen giao cdng nghe Den Tda soan 17-6-2011 Abstract This paper presents results electro catalysis ability by redox reaction create H2O2 of Carbon (C), C/Ppy, C/Ppy(oxit) materials and influence of nature of cathodic material, current density, concentration ratio between red Congo and iron (II) ion on red Congo treatment by electro-Fenton process The results showed in axit environment pH = C/Ppy(oxit) electrode had the highest removal efficiency The decrease of red congo concentration in treatment process was determined by UV-vis spectra method and COD indicator The prelimilary data indicated that using Ppy/CU| sMni 5O4 cathodic electrode, at mA/cm^ density, ratio CcR/CFe^'^= 0.25 mM/1 mM, the disintegrating efficiency of red Congo reached'over 70% after 7-hour treatment with current efficiency over 100% I.MQDAU Trong nhifng nam gan day, vifc nghifn eiiu xu ly nudc thai chiia cac hgp chat tgo mau hg azo (congo dd, methyl da cam, metyl dd ) dang dugc nhifu nha khoa hpcfrongva ngoai nudc quan tam nghifn cuu Fenton difn hoa la mdt gong eac phuong phap oxi boa tifn tien cho phep oxi boa khdng chgn Ige eae hgp chat hiru CO ddc hai khd phan buy dang duge ap dyng rdng rai gong xir ly nude thai Trong phan iing Fenton difn hda, H2O2 dxxqc sinh bang each khu hai electron cua oxi trfn mpt sd difn cue nhu cacbon kfnh, graphit, difn cue khuech tan [1 3] O2 + 2e + 2H2O -^ 2H2O2 (1) H2O2 hinh tac dyng vdi mdt lugng nhd chat xiic tac Fe^"" dugc thfm vao frong dung djeh tao gdc OH* ed kha nang oxi hda hau hft cae hgp chat hum CO (RH) theo phan iing sau: Fe^ + H2O2 + H ^ ^ O H ' + Fe^^ + H20 (2) Fe^^ + H2O2 ^ Fe^^ + H02* + H^ (3) OH* + R H ^ R * + H (4) Hifu suat khoang boa eae hgp chat hiru co phy thude vao chf difn boa, ban chat ciia eac chat d nhiem, pH eua dung djch va dae bift la vat lifu difn cue andt va eatdt Cae nghifn ciru trudc day cua chiing tdi da chi ring hifu irng Fenton difn hda cho phep khoang hda hoan toan eac hgp chat mau tdng hgp nhu metyl da cam, metyl dd vdi hifu suit ddng cao trfn difn cgc eatdt nen cacbon phu 489 compozit Ppy(oxit) Trong khudn khd bai bao nay, chiing tdi nghifn cuu khao sat anh hudng cua ban chat vat lifu eatdt, mat dp ddng ap dat, ndng congo dd dfn qua trinh xu ly congo dd bang hifu ung Fenton difn hoa DIEU KIEN THI/C NGHIEM Qua trinh tdng hgp mang polyme dan trfn difn cgc cacbon (C) dugc thgc hien binh difn hda hf ba difn cgc vdi difn cgc lam vifc la cacbon dgng hinh try, xung quanh phu epoxy cho dien tfch lam vifc khdng ddi bang cm^; difn cgc ddi la ludi platin va difn cgc so sanh la ealomen bao hda KCl tren thiet bj Autolab (Ha Lan) dgt tgi Vifn Ky thuat nhift ddi, dung djch KCl 0,5 M chiia pyrrol 0,1 M ed va khdng ed oxit Cui_5Mni_504 tdn tgi dudi dgng huyfn phii dung djeh nhd khuay tir Kha nang xiie tac difn hda ciia cae ldp phu polyme dan duge danh gia bang phuomg phap difn the dirng 50 ml dung djch Na2S04 0,05 M d pH = 3, cd va khdng sye oxi Trong phep nay, difn thf duge ap dgt tir difn thf mgeh hd vf phfa catot vdi bude nhay thf 100 mV, thdi gian cua mdi budc nhay thf dugc ap dgt khoang 1000s Qua trinh xir ly congo dd duge thue hifn hf hai difn cgc bing phuomg phap ddng ap dgt (galvonostatie) vdi eae mat dp ddng la 1; 5; 10 mA/cm^ dung djch Na2S04 0,1 M, pH = chiia Fe^"^ mM, ndng dp congo dd (C32H2206N6Na2S2) la 0,5 mM; 0,25 mM va 0,125 mM, duge sye oxi vdi tde 0,5 l/phut Su suy giam ndng congo qua trinh Dinh Thi Mai Thanh vd cgngsu TCHH, T 49(4), 2011 xir ly dugc nghien cum bing phd UV-vis tren thiet bj UV-speetrometer, Citra 40-My, tgi Vifn Ky thugt nhift ddi Hifu suit phan buy duge tinh theo cdng thiic [4]: A., - A il( %) =- cac hda chit sir dyng nghien ciru deu cd dg tinh khiet cao (PA) .100% Trong dd: i]: I lifu suit phan huy (%); AQ: cudng dg hip thy tgi thdi diem ban diu; A,: eudng dg hip thy tgi thdi diem t Sg phan huy congo dd qua trinh xir ly dugc xac djnh thdng qua nhu clu oxi hda hgc (COD), xac djnh bing each sir dyng lugng du ehat oxi hda mgnh K2Cr207 vdi xuc tac Ag2S04 Lugng K2Cr207 ban diu va lugng du sau oxi hda hoan toan cac hgp chat hiru co dugc chuan dg bang muoi Morh vdi chi thj diphetylamin Hifu suit ddng difn cua qua trinh xir ly (H) dugc tinh theo cdng thire [5]: H(%) 0.0- Vdi: AcoD - Dg bi^n thifn chi so COD (^1), V Thf tfch dung djch difn phan (1), F Hing so Faraday, Q Difn tfch qua binh (C) KET QUA VA T H A O LUAN 3.1 Kha ndng xiic tac difn hoa cua mang Ppy(oxit) cho phan irng khir oxi tao hidro peoxit tren difn cgc catot graphit Ket qua kha nang xiic tae difn hda ciia ba loai vgt lifu difn cgc C; C/Ppy va C/Ppy(oxit) dugc bifu dien tren hinh Tir thj cd thf nhgn thay mat dp ddng eatdt cua difn cgc C/Ppy(oxit) ludn dgt gia trj cao nhat Dieu chirng td kha nang xuc tac cho qua trinh khir oxi hda tan tgo H2O2 cua difn cue C/Ppy(oxit) la Idn nhit va md kha nang irng dung vat lifu difn cgc xir If mdi trudng bang phuong phap Fenton difn hda •— — • — • — • - — • — • -•— ^ • • ^^'""'^ s -0.2- E • -0.4- -0.6- / —•—c • —•—C/Ppy -A-C/Ppy(Cu,5Mn,,0,) • -0.8- -0.8 -0.6 -0.4 -0.2 E(V/SCE) 0.0 • 0.2 Kmh 1: Mat ddng catot tgi cae difn the ap dgt dung djeh pH = 3.2 Anh hirdng ciia vat lieu catot tuomg limg vdi sg phan hiiy clu triic -N=N- din tai lam giam dan ndng dg congo dd dung dich 3.2.1 Ket qud UV-Vis difn phan Ket qua xac djnh sg bifn thifn hifu suit phan Sg suy giam ndng va bien thifn hifu suit hiiy Congo dd cho thiy: Sau gid difn phan hieu phan hiiy congo dd 0,25 mM qua trinh xOr ly suit phan hiiy dgt 32% doi vdi difn cgc C; 42% dfi nhd hifu ling Fenton difn hda d\xcsc bieu dien tren vdi difn cgc C/Ppy va 65% doi vdi difn cue eac hinh va3 C/Ppy(Cui,5Mni,504) Dieu khing djnh qua trinh Phd UV-vis Clia congo dd tgi pH = trude xir ly Congo dd 0,25 mM nhd hifu iing Fenton dien xur ly duge dae trung bdi mdt dai phd viing hda sii dyng difn cgc C/Ppy (Cui.jMn 1,504) d mat nhin thay vdi cgc dgi hap thy d 560 nm Doi vdi ca ddng mA/cm^ cho hifu suit cao hon ca kha ba logi difn cgc tgi mat ddng mA/em^, cudng nang xiic tac tot cua loai difn cue ddi vdi qua pic tgi 560nm deu giam dan theo thdi gian xii ly trinh khu oxi hda tan tao H262 490 TCHH, T 49(4), 2011 Anh hu&ng cua mgt so yeu td den -T-c —•—C/Ppy —• —C/Ppy(oxit) I I I I I I I I I I I I I I I 200,0 300,0 6000 7000 800.0 t(h) Congo nJ LTinh 2: Phd UV-vis cua congo dd theo thdi gian phan hiiy tgi mat dp ddng 5mA/cm", trfn difn cgc catot C/Ppy((oxit) LTinh 3: Bien thifn hifu suit phan hiiy congo dd 0,25 mM theo thdi gian tgi mat ddng ap dgt mA/cm C/Ppy(oxit) Mgt lin nira khang djnh rang tgi eiing mdt thdi difm gia trj difn lugng Q nhu nhung sir dung difn cgc eatdt la C/Ppy(oxit) vdi tfnh Bfn cgnh ket qua thu duge bing phuomg phap UV-vis, dung djch congo dd sau difn phan cdn dugc nang xuc tae tdt cho qua trinh khir oxi hda tan tgo dem phan tich COD df xac djnh suy giam chi so H2O2 da lam tang toe dp cua qua trinh oxi hda congo COD theo thdi gian xir ly va bien thien hifu suat dd dd lam cho dp suy giam COD cao hon so vdi ddng difn khoang hda congo dd (hinh 3, 4) Ddi vdi sii dyng difn cgc C va C/Ppy KSt qua xae djnh ca ba trudng hgp su dung difn cgc eatdt C; C/Ppy; hifu suat ddng difn khoang hda congo dd eung cho C/Ppy(oxit), suy giam COD deu tang din theo thiy sir dyng difn cgc C/Ppy(oxit) qua thdi gian difn phan Sau gid xu ly suy giam trinh difn phan tgi nhung thdi difm ban dau sau COD dgt 180 dom vj COD ddi vdi trudmg hgp su gid difn phan hifu suit ddng dgt 130%) cao hon so dung difn cue eatdt C; 210 don vj COD ddi vdi vdi trudng hgp su dyng difn cue C/Ppy vdi hifu suat trudng hgp dimg difn cgc eatdt C/Ppy va 240 dom vj ddng 104%) va cao hon nhieu so vdi sii dyng COD ddi vdi trudng hgp diing difn cue eatdt la difn cue C vdi hifu suit ddng ehi 65%) 3.2.2 Ket qud xdc djnh COD 150 250 -A-C 120 — • — C/Ppy —•—C/Ppy(oxit) l' t(h) (b) (a) LTinh 4: Do suy giam COD (a) va hifu suit ddng (b) qua trinh phan hiiy congo dd 0,25 mM theo thdi gian tgi mat dg ddng ap dat mA/cm chuyen qua hifu suit phan buy va suy giam COD ludn dgt gia trj eao hon so vdi trudng hgp difn phan Anh hudng eiia mat ddng dfn qua trinh xu ly tgi mat ddng 5; 10 mA/cml gia trj difn lugng difn hda congo dd dugc chi tren cac hinh va Q = A.h/1 hifu suit phan hiiy tgi cae mat ddng Ket qua cho thiy tgi mat ddng mA/cm^ d cac mA/cm^; mA/cm^; 10 mA/cm^ dgt eae gia trj lin thdi diem khac cd ciing gia tri difn lugng Q lugt la: 75%; 42% va 34%; suy giam COD eung 3.3 Anh hirdng cua mat dong Dinh Thi Mai Thanh vd cgngsy TCHH, T 49(4), 2011 giam din theo trgt tg: 280 don vj COD (d ImA/cm^); 240 don vj COD (d mA/cm^); 210 don vjCOD(dl0mA/em^) Ben canh tai nhung thdi diem ban dau cua qua trinh difn phan, hifu suit ddng difn phan hiiy dat gia trj kha cao duge ly giai la cd sg tham gia eiia hifu irng Fenton difn hda nen xay nhieu qua trinh ddng thdi nhu: oxi hda trgc tiep congo dd trfn dien cgc andt, oxi hda gian tiep congo dd trfn difn cue eatdt nhd cae tac nhan oxi hda mgnh gay ra, Mat khac eac qua trinh xay tren be mgt difn cgc tao cac tac nhan oxi hda mgnh cd kha nang oxi hda hoan toan congo dd va cae hgp chat trung gian dan den hifu suit ddng difn dgt gia trj rat eao, dae biet trudmg hgp sir dung dien cue eatdt la C/Ppy(oxit) d mat dp ddng mA/em^ hifu suat ddng dat gia trj kha cao tdi 157,6% Q = 0,25 A.h/1 3.4 Anh hu-dng ciia nong dg congo Ket qua phan tfch UV-Vis va xac djnh COD qui trinh xu If congo dd d cac ndng dg khac nhau, tgi mgt dg ddng mA/cm^ dung djch Na2S04 0,1 M, pH = chira Fe^^ mM dugc bifu dien trfn hinh va Tir thj cd the thiy ring vdi eiing ham lugng ion Fe^"^ dung djeh difn phan, nong dg congo dd giam din (tir 0,5 mM den 0,125mM) hifu suit phan buy tuong img tang din Tuy nhien hifu suit ddng difn phan buy congo 0.25mM dgt gia trj cao nhat 157,6%) so vdi hai trudng hgp nong dg 0,5 mM (78,8%) va 0,125 mM (52,5%) sau I gid difn phan Dieu chirng td rang ti If ve nong dg giifa congo dd va ion Fe^^ cd vai trd quyet djnh den hifu suit cua qua trinh xir ly congo dd Theo dd ti If giira nong dg congo dd va nong dg ion Fe^^ bing 0,25:1 se cho hifu qua xir ly cao hon ca 80 -•— mA/cm -•— mA/cm -A— 10 mA/cm' LTinh 5: Bifn thien hifu suat phan huy congo dd 0,25mM theo dien lugng Q, sir dung difn cgc catot C/Ppy(oxit) Hinh 6: Dg suy giam COD va bifn thien hifu suat ddng difn phan hiiy congo dd 0,25 mM theo Q tren catot C/Ppy(oxit) 45 * -•—O.SmM -•—0.25mM -A-0.125mM —•— O.SmM —•— 0.25mM A0.i25mM 120- 30 ã^ ^ ^^ô ã 8015- -A- -A- ^A- •^ ^~~"A -•- -•- 40- •^, U ^•~ ~^B— —A- ^ » • • •——•- 04 t(h) t(h) LTinh 7: Bien thien hifu suat phan buy congo dd theo thdi gian tgi mat ddng mA/em^ tren catot C/Ppy(oxit) AQ'-) LTinh 8: Su bifn thien hifu suit ddng difn phan buy congo theo thdi gian, tai mat dg ddng mA/cm^ tren catot C/Ppy(oxit) TCHH, T 49(4), 2011 Anh hu&ng ciia mgt sd yeu td din KET LUAN 157,6%) sau gid xir ly Khing djnh duge kha nang xiic tae tot cua mang compozit Ppy(oxit) doi vdi qua trinh khii oxi hda tan tgo H2O2 lam tang dang ke hifu qua frong xir ly nudc thai bang hifu dng Fenton difn hda cac ket qua thu dugc cho thay hifu ung Fenton difn hoa cd kha nang phan hiiy hifu qua congo ndng 0,25 mM tgi mgt dg ddng mA/cm trfn difn cgc eatdt C/Ppy(oxit) dung djch Na2S04, pH = cd mat ion Fe^^ mM dugc sye khf oxi Q difu kifn sau 35 gid xu ly, hifu suat phan hiiy congo dd dgt 75%o Cac kft qua xac djnh COD cho thay theo thdi gian difn phan COD giam din, sau gid difn phan chi so COD da suy giam tir 320 mg/l xudng cdn 40 mg/l dam bao du tifu chuin thai mdi gudng hoge sir dyng tudi tifu, frong trgt Hifu suit ddng difn tuomg ung rit ldm, dgt gia trj TAI LIEU THAM KHAO D A Pozzo, L D Palma, C Merli, E Petrucci J Appl Electrochem., 35, 413 (2005) A A Gallegos, P Pletcher Electrochim Acta 44 (1998)853 Z M Qiang, J H Chang, C P Huang Water Res., 36, 85 (2002) Minghua Zhou, Qinghong Yu, Lecheng Lei, Geoff Barton Separation and Purification Technology, 57, 380 - 387 (2007) Nguyen Hong Thai Nghien ciiu tong hgp difn cue mang compozit tren ca sd polyme dan difn va oxit phijc hgp nhim umg dung nhu difn cgc xiic tac dien h6a xu ly m6i trudng, Luan vSn thac sT h6a hpc, Trudng DHSP Ha Npi (2007) Lien he: Dinh Thi Mai Thanh Vifn Ky thugt Nhift ddi Vifn Khoa hgc va Cdng nghf Vift Nam 18 Hoang Quoc Vift, Clu Giiy, Ha Ndi 493 ... va3 C/Ppy(Cui,5Mni,504) Dieu khing djnh qua trinh Phd UV-vis Clia congo dd tgi pH = trude xir ly Congo dd 0,25 mM nhd hifu iing Fenton dien xur ly duge dae trung bdi mdt dai phd viing hda sii dyng... 7000 800.0 t(h) Congo nJ LTinh 2: Phd UV-vis cua congo dd theo thdi gian phan hiiy tgi mat dp ddng 5mA/cm", trfn difn cgc catot C/Ppy((oxit) LTinh 3: Bien thifn hifu suit phan hiiy congo dd 0,25... giai la cd sg tham gia eiia hifu irng Fenton difn hda nen xay nhieu qua trinh ddng thdi nhu: oxi hda trgc tiep congo dd trfn dien cgc andt, oxi hda gian tiep congo dd trfn difn cue eatdt nhd cae