Zinc extraction from sewage sludge with [S, S]-EDDS
来源期刊：中南大学学报(英文版)2012年第12期
论文作者：ZHANG Li-hua (张丽华) ZHANG Hua (张华)
文章页码：3546 - 3550
Key words：zinc; [S, S]-ethylenediaminedisuccinic acid; extraction; sewage sludge; chelant; biodegradablility
Abstract: An environmentally friendly biodegradable chelant, [S, S]-ethylenediaminedisuccinic acid (EDDS), was used to separate heavy metals from sewage sludge based on chemical extraction technology. The extraction of zinc from sewage sludge with an aqueous solution of EDDS was studied under various conditions. It is found that the extraction efficiency of zinc using EDDS is equivalent to that using ethylenediaminetetraacetic acid (EDTA) at the molar ratio of chelant to total heavy metals of 1:1 over pH range of 5-9. EDDS is capable of extracting zinc from the sludge. The extraction efficiency is improved obviously and reaches a higher value within pH range from 3 to 10. The extraction efficiency maintains at about 65% when pH ≥ 4.5 and the ratio of 10:1. By comparing the species contents of the zinc in sewage sludge before and after the extraction, it is found that the extracted zinc mainly comes from the acid soluble, reducible and oxidizable fractions.
ZHANG Li-hua (张丽华)1, ZHANG Hua (张华)2
(1. Department of Chemistry and Biology Engineering, Sanming University, Sanming 365004, China;
2. State Key Laboratory of Pollution Control and Resource Reuse(Tongji University), Shanghai 200092, China)
Abstract:An environmentally friendly biodegradable chelant, [S, S]-ethylenediaminedisuccinic acid (EDDS), was used to separate heavy metals from sewage sludge based on chemical extraction technology. The extraction of zinc from sewage sludge with an aqueous solution of EDDS was studied under various conditions. It is found that the extraction efficiency of zinc using EDDS is equivalent to that using ethylenediaminetetraacetic acid (EDTA) at the molar ratio of chelant to total heavy metals of 1:1 over pH range of 5-9. EDDS is capable of extracting zinc from the sludge. The extraction efficiency is improved obviously and reaches a higher value within pH range from 3 to 10. The extraction efficiency maintains at about 65% when pH ≥ 4.5 and the ratio of 10:1. By comparing the species contents of the zinc in sewage sludge before and after the extraction, it is found that the extracted zinc mainly comes from the acid soluble, reducible and oxidizable fractions.
Key words:zinc; [S, S]-ethylenediaminedisuccinic acid; extraction; sewage sludge; chelant; biodegradablility
