: O : A. vanced Oxidation Processes, AOPs) 1. 1 UV- PC2501

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1 EL ECTROCHEMISTR Y Vol 8 No 3 Aug 2002 : (2002) ,2 3, 1 1 3, 2, 1 1, (1, ;2, ) :, :, Fe 2 + p H ( t),, Fe 2 + ESR : ; ; ; : O : A,, (Ad2 vanced Oxidation Processes, AOPs), OH [1 ] OH, OH [2 5, ] [6,7 ],,,,,, [8 12 ] [13 17 ] OH OH UV- PC2501 ( Hitachi, ) W YK-3003 : , : , Tel : (86-20) ; zsu edu cn : ( ), (990274) ; (A ) ; China Academic Journal Electronic Publishing House All rights reserved

2 ( ) PHS-3C p H ( ) J ES- RE1X ( ) GC- MS ( HP GC MS) ( ) : 400 mgl - 1, p H 1 2 1, ( ),,,, PVC 1 Fig 1 Schematic diagram of three di2 mensional electrochemical reac2 tor : (1) Anode ; (2) Support ; (3) 1 3 Particle electrode ; ( 4 ) Inlet of, compressed air ; (5) Reactor out2 let; ( 6 ) Micropore plate ; ( 7 ), Cathode g 250 ml 400 mgl - 1, 0 1 m 3 h - 1, 2 2 1, : O 2 + 2H + + 2e ϖh 2 O 2 (1) H 2 O 2 + Fe 2 + ϖho + HO - + Fe 3 + (2) Fe e ϖfe 2 + (3), Fe 2 + OH Fe 3 + Fe 3 + O 2, Fe 3 + O 2 Fe 2 +,,, OH OH, ESR, OH DMPO ( (4) ), OH : China Academic Journal Electronic Publishing House All rights reserved

3 3 : 329 ESR, ( 2) DMPO-OH, OH ( ), Fe 2 +, p H ( t),, ;, 1,, 10 V, 15 V,,, :2H 2 O ϖ4h + + O 2 + 4e 2 DMPO-OH ESR, 10 V, Fig 2 ESR spectrum of DMPO-OH :, ( 3,,, L, ),,,, 1, p H 5 8, 75 3 % p H 3 Fe 2 +, Fig 3 Distribution of particle of potential,fe 2 + and solution potential in the three- : Fe 2 + dimensional electrochemical reactor 0 0 g L g L - 1, 75 3 % 83 7 % Fe 2 + Fenton, (2) China Academic Journal Electronic Publishing House All rights reserved

4 (5) : H 2 O 2 + Fe 2 + ϖho + HO - + Fe 3 + (2) HO + Fe 2 + ϖho - + Fe 3 + (5) Fe 2 +, H 2 O 2 ( p H = 5 8 ) ; Fe 2 +, Fe 2 +,H 2 O 2 (2) (5) OH, 1 p H,,,O 2 H 2 O 2, Fe 2 +, H 2 O 2 OH,,,, 60 min, 90 % :, min - 1 Parameters 1 Tab 1 Influence of electrolysis conditions on aniline degradation in the three dimentional electrochemical reactor(reaction solution :aniline + FeSO 4 + H 2 SO 4 ) Applied voltage/ V Amount of FeSO 4 added to solution/ g(p H = 5 8) Removal ( %) Parameters p H( W FeSO4 = 0 25 g) Electrolysis time/ min Removal ( %) ,, nm, 50 min, GC- MS, 3 1) 4, Fig 4 UV spectra of aniline at various reaction intervals China Academic Journal Electronic Publishing House All rights reserved

5 3 : 331, 2) OH,,,,, Electrochemical Degradation of Organic Wastewater by Three-Dimensional Electrode Reactor HE Chun 1,2 3,AN Tai-cheng 1,XION G Ya 1 3,SHU Dong 2,HU Hui-ling 1,ZHU Xi- hai 1 (1 School of Chemist ry and Chemical Engineering, Zhongshan U niversity, Guangz hou , China ; 2 Depart ment of Chemist ry, Zhaoqing College, Zhaoqing , China) Abstract : The elect rochemical degradation of aniline was investigated using a novel elect ro2 chemical reactor, t hree- dimensional elect rode reactor The experimental result s indicated t hat t he reactor could efficiently remove aniline The removal efficiency could be att ributed to a combina2 tion of direct and indirect elect rochemical reactions,t hat is,anodic oxidation and oxidation of elec2 trogenerated H 2 O 2 and hydroxyl radicals generated in electro- Fenton process It was also observed that the removal efficiency was significantly dependent on applied voltage,fe 2 + concentration,p H value and electrolysis time In the experimental range they all have a positive effect on the re2 moval efficiency except for p H value Furt hermore,hydroxyl radicals generated in elect ro- Fenton process was confirmed whith the method of spin-trapping ESR Key words : Three- dimensional elect rode, Elect rochemical degradation, Organic waste wa2 ter, OH radicals Reference s : [1 ] Huang C P, Dong C G, Tang Z H Advanced chemical oxidation :its present role and potential future in haz2 ardous waste treatment [J ] Waste Management,1993,13 :361 [ 2 ] Hsiao Y L, Nobe K Hydroxylation of chlorobenzene and phenol in a packed bed flow reactor with electrogen2 erated Fenton s reagent [J ]J Appl Electrochem,1993,23 :943 [ 3 ] Tomat R Electrochemical oxiation of toluene promoted by OH radicals[j ]J Appl Electrochem,1984,14(1) : 1 [4 ] Oturan M A An ecologically effective water treatment technique using electrochemically generated hydroxyl radicals for in situ destruction of organic pollutants : Application to herbicide 2, 4- D [ J ] J Appl China Academic Journal Electronic Publishing House All rights reserved Elec2

6 trochem, 2000,30(4) :475 [5 ] Brillas E, Calpe J C, Casado J Mineralization of 2,4-D by advanced electrochemical oxidation processes[j ] Water Res,2000,34(8) :2 253 [6 ] Pletcher D, Weinberg N L The green potential of electrochemistry, Part 1 : the fundamentals [J ] Chem Eng,1992,8 :98 ; Part 2 :the applications[j ] Chem Eng,1992,11 :132 [ 7 ] Rajeshwar K,Ibanez J G,Swain G M Electrochemistry and environment [J ]J Appl Electrochem,1994,24 : [8 ] Belmant C,Cognet P,Berlan J,et al Application of an electrochemical pulsed flow reactor to electroorganic synthesis : Part 1 Reduction of acetophenone[j ] J Appl Electrochem,1998,28 :185 [ 9 ] Ogata Y, Tomizawa K, Takagi K Photooxidation of formic,acetic,and propionic acids with aqueous hydrogen peroxide[j ] Can J Chem,1981,59 :14 [10 ] Simonsson D Electrochemistry for a cleaner environment [J ] Chem Soc Rev,1997,26(3) :181 [11 ] Szanto D, Trinidad P, Walsh F Evaluation of carbon electrode and electrosynthesis of coumestan and cate2 cholamine derivatives in the FM01-LC electrolyzer[j ] J Appl Electrochem,1998,28 :251 [12 ] Didckmann G R,Langer,S H Selective electrogenerative oxidation of benzyl alcohol with platinum-graphite packed- bed anodes[j ]J Appl Electrochem,1997,27 :1 [13 ] Bisang J M Electrochemical treatment of waste solution containing ferrous sulfate by anodic oxidation using an undivided reactor[j ] J Appl Electrochem,2000,30 :399 [14 ] Grau J M,Bisang J M Cadmium removal from aqueous sulfate solutions by treatment with iron felts[j ] J Chem Technol Biotechnol,1998,73 :398 [15 ] El-Deab M S,Saleh M M, El-Anodouli B E, et al Electrochemical removal oflead ions from flowing elec2 trolytes using packed bed electrodes[j ] J Electrochem Soc 1999,146 :208 [16 ] Ragnini C A R,Di I R A,Bizzo W et al Recycled niobium felt as an efficient three- dimensional electrode for electrolytic metal ion removal[j ] Water Res,2000,34 :3 269 [ 17 ] Walsh F,Reade G Design and performance of electrochemical reactors for efficient synthesis and environmen2 tal treatment Part 2 Typical reactors and their performance[j ] Analyst,1994,119 : China Academic Journal Electronic Publishing House All rights reserved