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.