Study on the transfer characteristic of heavy metals from sludge compost to grapefruit
污泥果肥利用中重金属迁移特征研究

To reuse municipal sludge safely, study on the transfer characteristic of heavy metals in soil, leaf and pulp of grapefruit was conducted after grapefruits were fertilized by sludge compost from Shiweitou wastewater treatment plant of Xiamen City. Results showed that the enrichment ability of cadmium in soil was the largest. The transfer and accumulation ability of heavy metals from soil to grapefruit leaves was much greater than that to pulp, so sludge compost can not be used for edible leafage plants directly. The transfer and accumulation ability of chromium to grapefruit leaves, nickel to pulp from soil was strongest, respectively. The pollution of cadmium in soil aggravated and the transfer ability of chromium to grapefruit leaves, nickel to pulp from soil was enhanced after grapefruits were fertilized by sludge compost. Concentration of nickel must be reduced before sludge application on grapefruit and concentration of copper, zinc, nickel, chromium and cadmium, content of which was very high in sludge, must be tracked and tested during the application.