使用可生物降解螯合剂乙二胺二琥珀酸从污水污泥中提取铜

Extraction of copper from sewage sludge using biodegradable chelant EDDS.

作者信息

Zhang Lihua, Zhu Zhiliang, Zhang Ronghua, Zheng Chengsong, Zhang Hua, Qiu Yanling, Zhao Jianfu

机构信息

State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, China.

出版信息

J Environ Sci (China). 2008;20(8):970-4. doi: 10.1016/s1001-0742(08)62195-6.

DOI:10.1016/s1001-0742(08)62195-6

PMID:18817077

Abstract

[S,S]-Ethylenediaminedisuccinic acid (EDDS), a biodegradable chelant, was used to separate the heavy metals from the sewage sludge based on chemical extraction technology. Under various conditions, the extraction experiments were carried out for the sewage sludge from Shanghai Taopu Municipal Wastewater Plant, China. The influences of pH and the concentration of EDDS on the extraction efficiency for copper (Cu) were discussed. The results showed that EDDS had higher extraction efficiency for Cu from the sewage sludge than other heavy metals. The system pH and the concentration of EDDS had a significant effect on the extraction efficiency. The extraction efficiency of Cu increased gradually with the increase of system pH and reached a higher efficiency within pH range of 3-10. The extraction efficiency maintained at approximately 70% when the pH > or = 4.5 and the molar ratio of EDDS to total heavy metals was 10:1. From the fractional analysis of the heavy metals in sewage sludge before and after the extraction, it was found that the extracted Cu mainly came from the following four fractions, i.e. water soluble, acid-soluble, reducible, and oxidizable fractions.

摘要

[S,S]-乙二胺二琥珀酸（EDDS）是一种可生物降解的螯合剂，基于化学萃取技术用于从污水污泥中分离重金属。在中国上海桃浦城市污水处理厂的污水污泥上，在各种条件下进行了萃取实验。讨论了pH值和EDDS浓度对铜（Cu）萃取效率的影响。结果表明，EDDS对污水污泥中Cu的萃取效率高于其他重金属。体系pH值和EDDS浓度对萃取效率有显著影响。Cu的萃取效率随体系pH值的升高而逐渐增加，在pH值为3 - 10范围内达到较高效率。当pH≥4.5且EDDS与总重金属的摩尔比为10:1时，萃取效率维持在约70%。通过对萃取前后污水污泥中重金属的分级分析发现，萃取的Cu主要来自以下四个部分，即可水溶、酸溶、可还原和可氧化部分。