ABSTRACT

The mobility and bioavailability of heavy metals in sewage sludge are the major risks to utilize for agricultural application. In this study, the chemical speciation of Cu, Ni, Cr, and Zn in the Lanzhou municipal sewage sludge were investigated with the addition of a natural attapulgite. The influences of attapulgite amendment in sewage sludge on heavy metals stabilization were evaluated by investigating the leaching procedure and sequential chemical extraction experiments. The sequential extraction procedure described by European Community Bureau of Reference was used in sludge to determine the distribution of heavy metal species. The addition of attapulgite accelerated more reducible speciation of all metals transformed into residual speciation evidently. It reduced the leaching content of metals significantly and decreased the ecotoxicity accounted for the germination index values climbed rapidly with increased attapulgite addition.

Implications: This research developed a method to stabilize heavy metals in municipal sewage sludge with clay. The activated attapulgite improved the treatment of sewage sludge containing heavy metals, and reduced the environmental risk of heavy metals.

摘要

污水污泥中重金属的流动性和生物利用度是农业应用的主要风险。在这项研究中，通过添加天然凹凸棒石，研究了兰州城市污水污泥中 Cu、Ni、Cr 和 Zn 的化​​学形态。通过研究浸出程序和连续化学提取实验，评估了污水污泥中凹凸棒石改良剂对重金属稳定的影响。欧洲共同体参考局描述的顺序提取程序用于污泥中以确定重金属种类的分布。凹凸棒石的加入明显加速了所有金属更可还原的形态转化为残余形态。

启示: 本研究开发了一种用粘土稳定城市污水污泥中重金属的方法。活性凹凸棒改善了含重金属污水污泥的处理，降低了重金属对环境的危害。