N,N-双(二硫代羧基)乙二胺对微量络合镍的深度脱除特性研究  

Characterizing the deep removal of trace complex nickel ions by N,N'-bis-( dithiocarboxy) ethylenediamine

作　　者：肖晓[1] 邱伊琴 孙水裕[1,2,3] 叶茂友[1] 严苹方 叶子玮 

机构地区：[1]广东工业大学环境科学与工程学院,广州510006 [2]广东环境保护工程职业学院,佛山528216 [3]广东省环境保护矿冶行业重金属污染防治与职业教育重点实验室,广州510006

出　　处：《环境科学学报》2016年第9期3251-3257,共7页Acta Scientiae Circumstantiae

基　　金：广东省自然科学基金(No.2015A030308008);广东省环保厅专项资金项目(2016);广东省科技计划项目-协同创新与平台环境建设(No.2016A040403068);广东省教育厅高等院校学科建设专项资金(No.2014KTSP022)~~

摘　　要：以柠檬酸镍(CA-Ni)、酒石酸镍(TA-Ni)、焦磷酸镍(SP-Ni)3种低浓度模拟络合镍废水为研究对象,选用自制的重金属捕集剂N,N-双(二硫代羧基)乙二胺(EDTC),对废水中的Ni进行深度脱除.重点研究了EDTC投加量、初始p H、反应时间对Ni去除效果的影响及螯合沉淀物的沉淀性能和溶出特性,同时分析了EDTC去除络合Ni的机理.研究结果表明,处理初始浓度5 mg·L^(-1)的CA-Ni、TA-Ni、SP-Ni,p H为4~8,EDTC最佳投加量分别为60 mg·L^(-1)、55 mg·L^(-1)和70 mg·L^(-1),PAM(聚丙烯酰胺)为1 mg·L^(-1),反应时间2 min,Ni的出水浓度均低于0.05mg·L^(-1),去除率达99%以上.螯合沉淀物沉降性能好且在弱酸弱碱条件下能稳定存在.红外光谱图和元素分析结果表明:EDTC与Ni发生螯合反应,即EDTC直接脱除络合镍中的Ni2+,并与Ni2+生成更稳定的螯合产物EDTC-Ni,进而有效地去除废水中Ni.A heavy metal chelating agent,N,N’-bis-（ dithiocarboxy） ethylenediamine（ EDTC）,was synthesized to remove trace complex nickel from CANi（ citric acid,CA）,TA-Ni（ tartaric acid,TA）,and SP-Ni（ pyrophosphate,SP） simulated wastewater. Effect of EDTC dosage,p H and reaction time on Ni removal was investigated through single factor batch experiment. Besides,the stability and sedimentation property of chelated precipitates and the reaction mechanism of EDTC and Ni were also introduced. The optimized condition was under EDTC dosages of 60 mg·L-1,55 mg·L-1and 70 mg·L-1,respectively,p H 4 8,2 min of reaction time and 1.0 mg·L-1of the coagulant（ polyacrylamide,PAM）. The residual Ni2＋concentration could decrease to less than 0.05 mg·L-1from the initial concentration of 5. 0 mg·L-1,with the corresponding removal efficiency over 99%. The precipitates performed excellent sedimentation property and strong stability in both weak acidic and alkaline environment. The results of IR and organic elemental analysis indicatethat the chelating reaction could take place between EDTC and Ni2＋,and Ni2＋was directly captured from complex nickel ions,forming an insoluble chelation with EDTC. Therefore the Ni2＋was removed efficiently.

关 键 词：N N-双(二硫代羧基)乙二胺 螯合沉淀 微量络合镍 脱除特性 

分 类 号：X703[环境科学与工程—环境工程]