重金属在城市污水处理中的去除机理

由于重金属的毒性及致癌性，受重金属污染水体备受关注，去除水体中的重金属势在必行。活性污泥作为一种生物吸附剂，在处理低浓度重金属废水应用中前景广泛。以活性污泥为核心的城市污水处理厂在有效去除有机物的同时，对重金属也有一定的去除能力。通过综述城市污水系统中重金属迁变特性的最新研究，分析了活性污泥处理重金属废水的优越性、国内外污水处理厂对重金属的去除效果，推导出活性污泥去除重金属的可能机理，最后展望了城市污水处理厂去除重金属的前景和发展方向。

Mechanism of Heavy Metals Removal in Urban Wastewater Treatment Plant

Considering of the strong toxicity and carcinogenicity of heavy metals,heavy metal polluted water has received more and more attention,thus it is imperative to remove heavy metals from water. Activated sludge can be used as a biological adsorbent,and it is promising in the treatment of wastewater with low concentration of heavy metals. In urban wastewater treatment plants with activated sludge can not only remove organic matters effectively,but also reduce the content of heavy metals. On the basis of current literature on the removal characteristic of heavy metals in urban wastewater treatment plants,advantages of activated sludge process in the treatment of heavy metal wastewater and removal efficiencies of heavy metals in wastewater treatment plant at home and abroad were analyzed. The possible mechanism of heavy metal removal by activated sludge was also discussed,and finally an outlook of the prospect and development of heavy metal removal in urban wastewater treatment plant was provided.