Species Distribution of Heavy Metal in Sewage Sludge before and after Extraction with PESA
For the sewage sludge samples from Taopu Wastewater Treatment Plant in Shanghai, the species distribution and content of heavy metals in the sewage sludge have been investigated. The chemical forms of heavy metals before and after the extraction with aqueous solution of Poly-epoxy-succinic acid (PESA) were determined by modified BCR sequential extraction method. The microwave digestion results showed that the tested sewage sludge mainly contains six heavy metals and the content order is Zn＞Cu＞Cr＞Ni＞Pb＞Cd. It is found that the concentrations for Zn, Cu, Cr, Ni, Pb and Cd have exceeded the third grade limit of the sewage sludge for soil use respectively. The BCR sequential extraction showed that Cd and Zn in tested sewage sludge are mainly associated with reducible fraction and acid exchangeable fraction, Pb is mainly in reducible fraction and residual fraction, Ni is mainly in acid exchangeable fraction and oxidizable fraction, Cu is mainly in oxidizable fraction, and Cr is in oxidizable fraction and residual fraction. The Zn Cd, and Ni exist in more active forms and easy for bioavailability, which may result in potential bad impact on soil environment. After the extraction with PESA, the species distribution of heavy metals in the sewage sludge changed a lot. For Cd, Zn and Pb, the water soluble, acid exchangeable, reducible and oxidizable fractions reduced remarkably. For Ni, Cr and Cu, the easily mobile fractions also decreased obviously，but the oxidizable fraction still exists in a high proportion. We conclude that the extracted heavy metals from sewage sludge with PESA mainly come from water soluble, acid exchangeable, reducible fractions and part of oxidizable fraction.
sewage sludge heavy metal distribution BCR sequential extraction PESA
ZHANG Lihua ZHU Zhiliang ZHANG Hua QIU Yanling ZHAO Jianfu
State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, Ch State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, Ch
国际会议
2007环境科学与技术国际会议(The 2007 International Symposium on Environmental Science and Technology)
北京
英文
2007-11-13（万方平台首次上网日期，不代表论文的发表时间）