城市污泥中重金属的形态分布和处理方法的研究

采用室内实验方法，研究了城市污泥中重金属的形态分布特征和转化机理，并对重金属的加硫酸根稳定和酸浸出两种处理方法进行了探讨。结果表明，污泥中约73％的Zn和70％的Ni以不稳定态存在，约72％的铜以硫化物及有机结合态形式存在，其他重金属主要以稳定态存在；厌氧消化工艺对可交换的离子态重金属的转化有明显的促进作用。通过向污泥中投加SO4^2-可以在一定程度上提高Zn的稳定性。酸浸出试验中：在pH＝2时，污泥中Zn的浸出率达到30％以上，Ni的浸出率达到40％以上，Cu基本不被浸出。

The Research on State Distribution and Disposal Process of Heavy Metal in Municipal Sludge

This paper evaluated the state distribution of heavy metals in municipal sludge and two disposal processes.The results showed that:About 73%Zn and 70%Ni ex it in unstable formand 72%Cu exit in c ombined with sulphide and organismf orm;Other heavy metals mainly exit in stable fo rm;Anaerobic digestion process has an obviously influence on the concen tration of heavy metal in exchangeable ionic form and the stability of Zn in sludge could increase by addingSO 42- ,which can form S 2- ion in sludge;Acid extraction showed that:Cu was not extracted at pH =2,whereas the percent age Zn and Ni extracted was beyond 30%and 40%.