合肥及周边城市污水污泥重金属含量和农用潜在生态风险评价

Investigation of heavy metals contained in sewage sludge from municipal wastewater treatment plants from five cities and evaluation on their potential ecological risks in agricultural utilization

测定合肥市及周边蚌埠,阜阳,黄山,宿州等城市7个污水处理厂污泥、生物反应器活性污泥及污水中5种重金属Pb,Cr,Cu,Zn,Cd的含量;计算污水处理厂对污水中重金属的去除,及污泥重金属去除负荷;参比安徽省土壤重金属元素背景值和全球土壤沉积物重金属元素平均值,用潜在生态危害指数法对污泥中重金属作毒性分析、污染程度评价和潜在生态风险评价;对比国家污泥农用标准,给出污泥农用建议。结果表明不同背景值下,污染程度和潜在生态风险评价差异较大,以安徽省土壤重金属元素含量为背景值评价,单因子Cd的污染程度"极强",使潜在生态风险处在"很强"范围;以全球土壤沉积物重金属含量平均值为背景值,评价潜在生态风险只有部分样品处在"很强"范围。

Determination were conducted of five heavy metals content of Pb,Cr,Cu,Zn,and Cd in sewage sludge from municipal wastewater treatment plants,the biological reactions and the waster water in Hefei,Bengbu,Fuyang,and Huangshan city.The heavy metals removal rates and sludge removal loads of heavy metal were calcu-lated.Compared with the background values of heavy metals in soil of Anhui province and average background val-ues of that in Earth sediment,the toxicities of heavy metals were analyzed.Their pollution levels and potential eco-logical risk were evaluated using potential ecological risk index.Some advices on agricultural application of the sewage sludge were given according to the national standards.The results indicate that the pollution levels and po-tential ecological risk were different compared with different background values.The pollution level of factor of Cd was very serious compared with the background value in Anhui province leading to the serious potential ecological risk of the sewage sludge,while parts of them were serious compared with that in Earth sediment.