摘要
传统化学沉淀法存在对酸性及低浓度的络合态重金属去除率低的问题,为解决此问题,以三乙烯四胺、二硫化碳为原料合成了重金属捕集剂N,N-双(二硫代羧基)三乙烯四胺(TDTC),并采用红外光谱等分析方法对其结构和主要官能团进行了表征。以酒石酸铜、柠檬酸铜和EDTA铜3种络合铜为去除对象,研究了TDTC对络合铜的去除性能及去除机理。结果表明,在pH为3.0~9.0、TDTC投加量为1 mmol·L^(-1)、Cu质量浓度为50 mg·L^(-1)、PAM投加量为1 mg·L^(-1)条件下,Cu去除率可达到99.6%以上。进一步的沉淀表征分析结果表明,TDTC对络合Cu的去除过程存在螯合配位反应,具有与相应络合剂的竞争优势,能够把Cu从相应的络合剂中脱除并形成难溶的螯合沉淀,从而实现废水中Cu的有效去除。以上研究结果可为利用特异重金属捕集剂去除重金属的工程实践提供参考。
Wastewater containing complex heavy metal in acid and low-concentration is difficult to be treated effectively by traditional chemical precipitation.Triethylenetetramine and carbon disulfide were taken as raw materials to prepare a heavy metal chelating agent of N,N-bis(2-mercaptoethyl)triethylene-tetramine(TDTC)in a mixing solvent of ethylene glycol and deionized water.Fourier transform infrared spectra,scanning electron microscopy and elemental analysis were used to characterize the structure of TDTC.The removal performance and mechanism of TA-Cu(tartaric acid,TA),CA-Cu(citric acid,TA-Cu)and EDTA-Cu by TDTC were discussed.The experimental results show that at pH of 3.0 to 9.0,TDTC dosage of 1 mmol·L^(-1),reaction time of3 min and PAM dosage of 1.0 mg·L^(-1),over 99.6%Cu could be removed from a simulated wastewater containing complex Cu with initial concentrations of 50 mg·L^(-1).IR,XPS and SEM analysis on the chelate precipitate showed that the chelating reaction occurred between TDTC and Cu.The competitive edge on Cu cheating by TDTC could withdrew Cu from other complexing agents and led to the occurrence of insoluble chelated precipitate.Thus,Cu could be efficiently removed from wastewater.This research can provide theoretical guidance for removing heavy metal by heavy metal chelation in engineering practice.
作者
易爽
刘牡丹
宋卫锋
包炳钦
冯嘉颖
YI Shuang;LIU Mudan;SONG Weifeng;BAO Bingqin;FENG Jiaying(School of Environmental Science and Engineering,Guangdong University of Technology,Guangzhou 510006,China;Guangdong Institute of Resources Utilization and Rare Earth Development,Guangzhou 510000,China;State Key Laboratory of Rare Metal Separation and Comprehensive Utilization,Guangzhou 510000,China;Guangdong Provincial Key Laboratory of Mineral Resources Development and Comprehensive Utilization,Guangzhou 510000,China)
出处
《环境工程学报》
CAS
CSCD
北大核心
2021年第12期3844-3853,共10页
Chinese Journal of Environmental Engineering
基金
广东省科学院发展专项资金项目(2021GDASYL-20210103058)。
关键词
重金属捕集剂
络合Cu
螯合
去除机理
heavy metal chelating agent
complex copper
chelate
removal mechanism
