污泥果肥利用中重金属迁移特征研究

Study on the transfer characteristic of heavy metals from sludge compost to grapefruit

为了厦门城市污泥的安全利用,将石渭头污水处理厂污泥经过好氧堆肥后施用于柚子树,对重金属元素在土壤、树叶及果肉中的迁移特征进行了研究。结果表明:Cd在土壤中的富集能力强;重金属元素从土壤向树叶迁移累积能力比向果肉的大得多,污泥肥料不能用于叶类食用植物的施用;Cr向树叶、Ni向果肉的迁移累积能力强;泥肥的施用加重了土壤中Cd的污染,提高了Cr向树叶、Ni向果肉的迁移能力;污泥果肥利用需降低Ni的浓度,对污泥中含量较高的Cu、Zn、Ni、Cr和Cd需进行跟踪检测。

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.