施用城市污泥对土壤中重金属积累和迁移的影响

目的 了解城市污泥农用后土壤重金属的积累和迁移。方法 于1998年分不同季节，从苏州、无锡、常州3个城市污水处理厂采集污泥样本，用原子吸收光谱仪分析样本中重金属(Pb、Zn、Cu、Cd、Hg、As)含量和不同形态含量，分析污泥农用后土壤重金属积累及迁移特性。结果 城市污泥重金属含量远高于土壤背景值，3城市污泥中Zn含量均超标，分别达到1199，00、784．00、1216．00mg／kg。长期施用能导致土壤重金属积累。污泥中重金属具有一定的活性和潜在迁移性。结论 城市污泥农用可能会导致土壤和生物体重金属积累，存在着一定的环境重金属积累风险。

Accumulation and Movement of Heavy Metals in the Environment Through Sewage Sludge Using in Agriculture

Objective To know the accumulation and movement of heavy metals in the environment through sewage sluge using in agriculture. Methods The sewage sludge samples were collected from sewage treatment farms of Suzhou, Wuxi and Changzhou in the different seasons of 1998. The content and states of heavy metals were determined by AAS. The accumulation and movement of heavy metals were analyzed as sewage sludge was used in agriculture. Results The content of heavy metals in the sewage sludge was greatly higher than that in the soil background. Especially, the contents of zinc in the sewage sludge in three cities exceeded the related standard, the means were 1 199.00, 784.00 and 1 216.00 mg/kg respectively. A long term using of sewage sludge might induce heavy metal accumulation in the soil. Conclusion Sewage sludge used in agriculture may induce heavy metal accumulation in the soil and the organisms, so the risk of environmental heavy metals accumulation may increase.