六盘水污水处理厂污泥中重金属生态风险评价

Ecological Risk Assessment of Heavy Metalsin Sewage Sludge of Liupanshui Sewage Treatment Plant

研究了六盘水的污水处理厂污泥中Cu、Cd、Zn、Cr、Pb 5种重金属及其赋存形态的含量,运用地累积指数法和潜在生态危害法对污泥潜在生态风险进行评价。研究结果表明:冬季和夏季污泥中5种重金属含量均未超出我国城镇污水处理厂污泥处置园林绿化用泥标准中的最高允许含量。污泥样品中Cu、Cd、Zn主要以非稳定态存在,具有较强的生物可利用性。风险指数评价显示,Cd是污泥中重金属生态风险的主要贡献者,在污泥处理处置时要引起重视。

The contents of heavy metals （Cu, Cd, Zn, Cr and Pb） and their occurrence forms in sewage sludge of Liupanshui wastewater treatment plant were analyzed. The potential ecological risks were evaluated by the method of geoaccumulation index and potential ecological risk. The results showed that the content of 5 kinds of heavy metals in the sludge during winter and summer did not exceed the maximum allowable content in the disposol standard of sewage sludge from municipal wastewater treatment plant for greening gardens use. Cu, Cd and Zn in the sludge mainly in the non- steady state had a strong biological availability. Risk index evaluation showed that Cd was a major contributor to the ecological risk of heavy metals in the sludge, it should be paid attention to the content of Cd during the sludge treatment process in Liupanshui.