Effects of Sewage Sludge Application to Farming on Heavy Metals in Soil

Farming application is an important disposal method for reuse in sewage sludge,but the heavy metals in sewage sludge will entry the soil at the same time,which would be harmful to the environment.In this paper,the effects on contents and species of heavy metals were studied while sewage sludge was applied in farming.The results showed that the concentrations of heavy metals increased but their activities were reduced in the process.The risk that heavy metals harmed human health via food chain declined as a result.