[Phytoremediation of complex contaminants in sewage river sediment by maize]

Pot experiment was conducted to study phytoremediation of maize to heavy metal-organic contaminated sewage river sediment. Results show maize has different accumulation capacity to different heavy metal. The highest concentration ratio for Zn reaches 56.69% of total amount in sewage river sediment. Accumulated amount in shoot is 1985.56 mg kg(-1), accounting for 30.16% of total Zn in sediment. Root accumulating of Pb, Cu, Ni and Cd is larger than shoot. Cd accumulating in root is 2.33 mg kg(-1), accounting for 40.10% of total Cd in sediment. Amount of Zn, Pb, Cu and Ni accumulated in shoot has significant relation with ion exchangeable heavy metal amount, while has no relation with total heavy metal in plant. Some organic contaminants with high molecular weight become small and decompose into simple organic compound which can be easily absorbed by maize. The number of microorganisms and urease activity increase due to effect of maize rhizosphere. All these prove that maize has improved remediation efficiency of complex contaminants in sewage river sediment.