电絮凝同步去除水中铜(Ⅱ)和铬(Ⅵ)复合污染物的影响因素及其作用机理
|
摘要
铜(Cu(Ⅱ))和铬(Cr(Ⅵ))是水和废水中一类重要的重金属复合污染物。电絮凝(electrocoagulation,EC)是目前很有效的重金属深度处理技术,因此,采用电絮凝静态反应器对水中Cu(Ⅱ)和Cr(Ⅵ)的复合污染物的同步去除进行研究。在单极式连接条件下,考察电极材料、电流密度、初始pH、极板间距和电导率等因素对电絮凝效果的影响。结果表明,与铁电极相比,铝电极显示出更好的Cu(Ⅱ)和Cr(Ⅵ)同步去除效果。因此,采用铝电极进行因素筛选实验,筛选出的实验条件为:Cu(Ⅱ)的进水浓度为18.73~20.08 mg·L~(-1),Cr(Ⅵ)的进水浓度为12.98~14.35 mg·L~(-1),在初始pH为3~6,电流密度为11.57 A·m~(-2),极板间距为1 cm,电导率在899~2 000μS·cm~(-1)的范围内。去除结果表明,总铬(TCr)、Cr(Ⅵ)和Cu(Ⅱ)的去除率均在94%以上,出水Cu(Ⅱ)、TCr和Cr(Ⅵ)的浓度分别为0.081.24、0.491.21和0.120.49 mg·L~(-1),出水pH在6~9之间,可以满足《污水综合排放标准》(GB 8978-7996)要求。
Hexavalent chromium(Cr(Ⅵ)) and copper(Cu(Ⅱ)) are important heavy metal contaminants in water body and wastewater.Electrocoagulation(EC),as an effective heavy metal removal technology,has been commonly applied currently,therefore,an electrocoagulation static reactor was used for simultaneous removal of combined contaminants of Cr(Ⅵ) and Cu(Ⅱ) in this study.The effects of electrode material,current density,initial pH,plate spacing and conductivity on electrocoagulation were investigated under monopolar connection conditions.The results showed that the aluminum electrode exhibits better simultaneous removal efficiency of Cr(Ⅵ) and Cu(Ⅱ) than the iron electrode.Factor screening experiment was done by using aluminum electrode and the results indicated that,when the experimental conditions were designed as follows: the influent concentration of Cr(Ⅵ) was from 12.98 mg·L~(-1) to 14.35 mg·L~(-1) and the influent concentration of Cu(Ⅱ) was from18.73 mg·L~(-1) to 20.08 mg·L~(-1),the initial pH was in the range of 3 to 6,the current density was 11.57 A·m~(-2),the plate spacing was 1 cm and the conductivity was in the range of 899 μS·cm~(-1) to 2 000 μS·cm~(-1),then the removal efficiencies of total chromium(TCr),Cr(Ⅵ) and Cu(Ⅱ) were all beyond 94%.Accordingly,the effluent concentrations of Cu(Ⅱ),TCr and Cr(Ⅵ) were from 0.08 mg·L~(-1) to 1.24 mg·L~(-1),0.49 mg·L~(-1) to 1.21 mg·L~(-1) and 0.12 mg·L~(-1) to 0.49 mg·L~(-1),individually,and the effluent pH were between 6 and 9,which met the comprehensive wastewater discharge standard(GB 8978-7996).
Hexavalent chromium(Cr(Ⅵ)) and copper(Cu(Ⅱ)) are important heavy metal contaminants in water body and wastewater.Electrocoagulation(EC),as an effective heavy metal removal technology,has been commonly applied currently,therefore,an electrocoagulation static reactor was used for simultaneous removal of combined contaminants of Cr(Ⅵ) and Cu(Ⅱ) in this study.The effects of electrode material,current density,initial pH,plate spacing and conductivity on electrocoagulation were investigated under monopolar connection conditions.The results showed that the aluminum electrode exhibits better simultaneous removal efficiency of Cr(Ⅵ) and Cu(Ⅱ) than the iron electrode.Factor screening experiment was done by using aluminum electrode and the results indicated that,when the experimental conditions were designed as follows: the influent concentration of Cr(Ⅵ) was from 12.98 mg·L~(-1) to 14.35 mg·L~(-1) and the influent concentration of Cu(Ⅱ) was from18.73 mg·L~(-1) to 20.08 mg·L~(-1),the initial pH was in the range of 3 to 6,the current density was 11.57 A·m~(-2),the plate spacing was 1 cm and the conductivity was in the range of 899 μS·cm~(-1) to 2 000 μS·cm~(-1),then the removal efficiencies of total chromium(TCr),Cr(Ⅵ) and Cu(Ⅱ) were all beyond 94%.Accordingly,the effluent concentrations of Cu(Ⅱ),TCr and Cr(Ⅵ) were from 0.08 mg·L~(-1) to 1.24 mg·L~(-1),0.49 mg·L~(-1) to 1.21 mg·L~(-1) and 0.12 mg·L~(-1) to 0.49 mg·L~(-1),individually,and the effluent pH were between 6 and 9,which met the comprehensive wastewater discharge standard(GB 8978-7996).
引文
[1]刘玉玲,陆君,马晓云,等.电絮凝过程处理含铬废水的工艺及机理[J].环境工程学报,2014,8(9):3640-3644
[2]罗志勇,张胜涛,郑泽根,等.电化学法处理重金属废水的研究进展[J].中国给水排水,2009,25(16):6-10
[3]GONG Y,GAI L,TANG J,et al.Reduction of Cr(Ⅵ)in simulated groundwater by Fe S-coated iron magnetic nanoparticles[J].Science of The Total Environment,2017,595(9):743-751
[4]HEIDMANN I,CALMANO W.Removal of Ni,Cu and Cr from a galvanic wastewater in an electrocoagulation system with Feand Al-electrodes[J].Separation and Purification Technology,2010,71(3):308-314
[5]ALAJI B,YAVUZ Y,KOPARAL A.S.Electrocoagulation of heavy metals containing model wastewater using monopolar iron electrodes[J].Separation And Purification Technology,2012,86(8):248-254
[6]AOUDJ S,KHELIFA A,DROUICHE N.Removal of fluoride,SDS,ammonia and turbidity from semiconductor wastewater by combined electrocoagulation-electroflotation[J].Chemosphere,2017,180(9):379-387
[7]AOUDJ S,KHELIFA A,DROUICHE N,et al.Removal of fluoride and turbidity from semiconductor industry wastewater by combined coagulation and electroflotation[J].Desalination And Water Treatment,2016,57(39):18398-18405
[8]DELUNA M D G,WARMADEWANTHI,LIU J C.Combined treatment of polishing wastewater and fluoride-containing wastewater from a semiconductor manufacturer[J].Colloids And Surfaces A:Physicochemical And Engineering Aspects,2009,347(1/2/3):64-68
[9]JIN W,DU H,ZHENG S,et al.Electrochemical processes for the environmental remediation of toxic Cr(Ⅵ):A review[J].Electrochimica Acta,2016,191:1044-1055
[10]PAN C,TROYER L D,CATALANO J G,et al.Dynamics of chromium(Ⅵ)removal from drinking water by iron electrocoagulation[J].Environmental Science&Technology,2016,50(24):13502-13510
[11]HU C,WANG S,SUN J,et al.An effective method for improving electrocoagulation process:Optimization of Al13polymer formation[J].Colloids and Surfaces A:Physicochemical and Engineering Aspects,2016,489:234-240
[12]AOUDJ S,KHELIFA A,DROUICHE N,et al.Simultaneous removal of chromium(Ⅵ)and fluoride by electrocoagulationelectroflotation:Application of a hybrid Fe-Al anode[J].Chemical Engineering Journal,2015,267(1):153-162
[13]AOUDJ S,KHELIFA A,DROUICHE N,et al.HF wastewater remediation by electrocoagulation process[J].Desalination and Water Treatment,2013,51(7/8/9):1596-1602
[14]KESHMIRIZADEH E,YOUSEFI S,ROFOUEI M K.An investigation on the new operational parameter effective in Cr(Ⅵ)removal efficiency:A study on electrocoagulation by alternating pulse current[J].Journal of Hazardous Materials,2011,190(1/2/3):119-124
[15]KABDASLI I,ARSLAN T,OELMEZ-HANCI T,et al.Complexing agent and heavy metal removals from metal plating effluent by electrocoagulation with stainless steel electrodes[J].Journal of Hazardous Materials,2009,165(1/2/3):838-845
[16]HEIDMANN I,CALMANO W.Removal of Zn(Ⅱ),Cu(Ⅱ),Ni(Ⅱ),Ag(I)and Cr(Ⅵ)present in aqueous solutions by aluminium electrocoagulation[J].Journal of Hazardous Materials,2008,152(3):934-941
[17]SONG P,YANG Z,ZENG G,et al.Electrocoagulation treatment of arsenic in wastewaters:A comprehensive review[J].Chemical Engineering Journal,2017,317(1):707-725
[18]DANESHVAR N,OLADEGARAGOZE A,DJAFARZADEH N.Decolorization of basic dye solutions by electrocoagulation:An investigation of the effect of operational parameters[J].Journal of Hazardous Materials,2006,129(1/2/3):116-122
[2]罗志勇,张胜涛,郑泽根,等.电化学法处理重金属废水的研究进展[J].中国给水排水,2009,25(16):6-10
[3]GONG Y,GAI L,TANG J,et al.Reduction of Cr(Ⅵ)in simulated groundwater by Fe S-coated iron magnetic nanoparticles[J].Science of The Total Environment,2017,595(9):743-751
[4]HEIDMANN I,CALMANO W.Removal of Ni,Cu and Cr from a galvanic wastewater in an electrocoagulation system with Feand Al-electrodes[J].Separation and Purification Technology,2010,71(3):308-314
[5]ALAJI B,YAVUZ Y,KOPARAL A.S.Electrocoagulation of heavy metals containing model wastewater using monopolar iron electrodes[J].Separation And Purification Technology,2012,86(8):248-254
[6]AOUDJ S,KHELIFA A,DROUICHE N.Removal of fluoride,SDS,ammonia and turbidity from semiconductor wastewater by combined electrocoagulation-electroflotation[J].Chemosphere,2017,180(9):379-387
[7]AOUDJ S,KHELIFA A,DROUICHE N,et al.Removal of fluoride and turbidity from semiconductor industry wastewater by combined coagulation and electroflotation[J].Desalination And Water Treatment,2016,57(39):18398-18405
[8]DELUNA M D G,WARMADEWANTHI,LIU J C.Combined treatment of polishing wastewater and fluoride-containing wastewater from a semiconductor manufacturer[J].Colloids And Surfaces A:Physicochemical And Engineering Aspects,2009,347(1/2/3):64-68
[9]JIN W,DU H,ZHENG S,et al.Electrochemical processes for the environmental remediation of toxic Cr(Ⅵ):A review[J].Electrochimica Acta,2016,191:1044-1055
[10]PAN C,TROYER L D,CATALANO J G,et al.Dynamics of chromium(Ⅵ)removal from drinking water by iron electrocoagulation[J].Environmental Science&Technology,2016,50(24):13502-13510
[11]HU C,WANG S,SUN J,et al.An effective method for improving electrocoagulation process:Optimization of Al13polymer formation[J].Colloids and Surfaces A:Physicochemical and Engineering Aspects,2016,489:234-240
[12]AOUDJ S,KHELIFA A,DROUICHE N,et al.Simultaneous removal of chromium(Ⅵ)and fluoride by electrocoagulationelectroflotation:Application of a hybrid Fe-Al anode[J].Chemical Engineering Journal,2015,267(1):153-162
[13]AOUDJ S,KHELIFA A,DROUICHE N,et al.HF wastewater remediation by electrocoagulation process[J].Desalination and Water Treatment,2013,51(7/8/9):1596-1602
[14]KESHMIRIZADEH E,YOUSEFI S,ROFOUEI M K.An investigation on the new operational parameter effective in Cr(Ⅵ)removal efficiency:A study on electrocoagulation by alternating pulse current[J].Journal of Hazardous Materials,2011,190(1/2/3):119-124
[15]KABDASLI I,ARSLAN T,OELMEZ-HANCI T,et al.Complexing agent and heavy metal removals from metal plating effluent by electrocoagulation with stainless steel electrodes[J].Journal of Hazardous Materials,2009,165(1/2/3):838-845
[16]HEIDMANN I,CALMANO W.Removal of Zn(Ⅱ),Cu(Ⅱ),Ni(Ⅱ),Ag(I)and Cr(Ⅵ)present in aqueous solutions by aluminium electrocoagulation[J].Journal of Hazardous Materials,2008,152(3):934-941
[17]SONG P,YANG Z,ZENG G,et al.Electrocoagulation treatment of arsenic in wastewaters:A comprehensive review[J].Chemical Engineering Journal,2017,317(1):707-725
[18]DANESHVAR N,OLADEGARAGOZE A,DJAFARZADEH N.Decolorization of basic dye solutions by electrocoagulation:An investigation of the effect of operational parameters[J].Journal of Hazardous Materials,2006,129(1/2/3):116-122