电化学氧化处理模拟染料废水
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摘要
试验采用动态电化学氧化方法,通过调整氯化钠用量,实时在线测定了模拟酸性大红GR染料废水原水和出水的pH值、电导率以及电流,并离线测定了出水的脱色率与COD_(Cr)。结果表明:随着氯化钠用量的增加,模拟染料废水出水的脱色率增加,COD_(Cr)明显降低;阳极反应形成氢氧自由基和次氯酸促进染料分子降解;当阳极电流密度48 mA/cm~2,极板之间距离30 mm,停留时间8 min,染料质量浓度为50 mg/L时,脱色率达到99.8%,COD_(Cr)的去除率达到92.3%;每消耗1 kWh直流电和31 g的氯化钠时,可使1.736 g酸性大红染料脱色,或者去除16.1 g COD_(Cr),该技术具有良好的推广应用前景。
In this paper, dynamic electrochemical oxidation method is adopted mainly by sequentially increasing the dosage of sodium chloride. The p H value, electric conductivity and current of original and effluent of synthetic Acid Red GR dyeing wastewaters are recorded on-line, and the decolorization rate and COD_(Cr)of effluent streams are measured off-line. The results show that, with the increase of electrolyte sodium chloride dosage, the decolorization rate of simulated dye wastewater increases while COD_(Cr) decreases significantly. The hydroxyl radicals and hypochlorite produced in the anodic reaction promote the degradation of dye molecules. When the current density of the anode is 48 mA/cm~2, the distance between the plates is 30 mm, the residence time is 8 min, the dye concentration is 50 mg/L, the decolorization rate reaches 99.8% and the COD_(Cr)removal rate reaches 92.3%. The decolorization of 1.736 g Acid Red dye or the removal of 16.1 g COD_(Cr)can be achieved with the consumption of 1 kWh DC power and31 g sodium chloride. This implies electrochemical oxidation technique will possess broad application prospects.
In this paper, dynamic electrochemical oxidation method is adopted mainly by sequentially increasing the dosage of sodium chloride. The p H value, electric conductivity and current of original and effluent of synthetic Acid Red GR dyeing wastewaters are recorded on-line, and the decolorization rate and COD_(Cr)of effluent streams are measured off-line. The results show that, with the increase of electrolyte sodium chloride dosage, the decolorization rate of simulated dye wastewater increases while COD_(Cr) decreases significantly. The hydroxyl radicals and hypochlorite produced in the anodic reaction promote the degradation of dye molecules. When the current density of the anode is 48 mA/cm~2, the distance between the plates is 30 mm, the residence time is 8 min, the dye concentration is 50 mg/L, the decolorization rate reaches 99.8% and the COD_(Cr)removal rate reaches 92.3%. The decolorization of 1.736 g Acid Red dye or the removal of 16.1 g COD_(Cr)can be achieved with the consumption of 1 kWh DC power and31 g sodium chloride. This implies electrochemical oxidation technique will possess broad application prospects.
引文
[1]任南琪,周显娇,郭婉茜,等.染料废水处理技术研究进展[J],化工学报,2013,64(1):84-94.
[2]陈银生,张新胜,袁渭康,印染废水处理技术[J],化工进展,2001(5):39-42.
[3]李大鹏,电化学氧化处理印染废水的过程和特性[J],中国给水排水,2002,18(5):6-9.
[4]AMOURA R L,AZEVEDO E,LEITE S,et al.Removal of phenol in high salinity media by a hybrid process(activated sludge+photocatalysis)[J].Sep.Purif.Technol.,2008,60(2):142-146.
[5]PANIZZA M,CERISOLA G.Direct and mediated anodic oxidation of organic pollutants[J].Chem.Rev.,2009,109(12):6541-6569.
[6]SCIALDONE O.Electrochemical oxidation of organic pollutants in water at metal oxide electrodes:a simple theoretical model including direct and indirect oxidation processes at the anodic surface[J].Electrochim.Acta,2009(54):6140-6147.
[7]SANDHYA S,SARAYU K,SWAMINATHAN K.Determination of kinetic constants of hybrid textile wastewater treatment system[J].Bioresour.Technol.,2008(99):5793-5797.
[8]MOREIRA F,BOAVENTURA R,BRILLAS E,et al.Electrochemical advanced oxidation processes:A review on their application to synthetic and real wastewaters[J],Applied Catalysis B:Environmental,2017(202):217-261.
[9]李然,唐淑娟,刘桂英,印染废水电化学脱色研究[J],印染,2004,40(14):27-29.
[10]CARVALHO C,FERNANDES A,LOPES A,et al,Electrochemical degradation applied to the metabolites of Acid Orange 7 anaerobic biotreatment[J],Chemosphere,2007(67):1316-1324.
[11]HAMZA M,ABDEHEDI R,BRILLAS E,et al,Comparative electrochemical degradation of the triphenylmethane dye Methyl Violet with boron-doped diamond and Pt anodes[J],J.Electroanal.Chem.,2009(627):41-50,
[12]EL-GHEYMY A,CENTELLAS F,GARRIDO J,et al,Decolorization and mineralization of Orange G azo dye solutions by anodic oxidation with a boron-doped diamond anode in divided and undivided tank reactors[J],Electrochim.Acta,2014(130):568-576.
[2]陈银生,张新胜,袁渭康,印染废水处理技术[J],化工进展,2001(5):39-42.
[3]李大鹏,电化学氧化处理印染废水的过程和特性[J],中国给水排水,2002,18(5):6-9.
[4]AMOURA R L,AZEVEDO E,LEITE S,et al.Removal of phenol in high salinity media by a hybrid process(activated sludge+photocatalysis)[J].Sep.Purif.Technol.,2008,60(2):142-146.
[5]PANIZZA M,CERISOLA G.Direct and mediated anodic oxidation of organic pollutants[J].Chem.Rev.,2009,109(12):6541-6569.
[6]SCIALDONE O.Electrochemical oxidation of organic pollutants in water at metal oxide electrodes:a simple theoretical model including direct and indirect oxidation processes at the anodic surface[J].Electrochim.Acta,2009(54):6140-6147.
[7]SANDHYA S,SARAYU K,SWAMINATHAN K.Determination of kinetic constants of hybrid textile wastewater treatment system[J].Bioresour.Technol.,2008(99):5793-5797.
[8]MOREIRA F,BOAVENTURA R,BRILLAS E,et al.Electrochemical advanced oxidation processes:A review on their application to synthetic and real wastewaters[J],Applied Catalysis B:Environmental,2017(202):217-261.
[9]李然,唐淑娟,刘桂英,印染废水电化学脱色研究[J],印染,2004,40(14):27-29.
[10]CARVALHO C,FERNANDES A,LOPES A,et al,Electrochemical degradation applied to the metabolites of Acid Orange 7 anaerobic biotreatment[J],Chemosphere,2007(67):1316-1324.
[11]HAMZA M,ABDEHEDI R,BRILLAS E,et al,Comparative electrochemical degradation of the triphenylmethane dye Methyl Violet with boron-doped diamond and Pt anodes[J],J.Electroanal.Chem.,2009(627):41-50,
[12]EL-GHEYMY A,CENTELLAS F,GARRIDO J,et al,Decolorization and mineralization of Orange G azo dye solutions by anodic oxidation with a boron-doped diamond anode in divided and undivided tank reactors[J],Electrochim.Acta,2014(130):568-576.