Abstract: Effect of aeration on the release of Cu,Pb,Zn and Cd from the sediment of the Yitong River in Changchun was studied by simulation experiment, and the morphological changes of the heavy metals before and after aeration in sediment were analyzed too. The results show that the solubilisation kinetics of Cu,Pb,Zn and Cd differ from one metal to another, Zn release is more slowly than those of Pb and Cd, and the concentration of Cu in solution changes slightly. The re-adsorption or co-precipitation processes of Pb and Zn occur after a period of aeration. The concentration peaks of the heavy metals in the solutions appeare more rapidly, which means that the sediment has more ecological risks. The heavy metals in the sediment change from more stable forms to those easily assimilated by microorganisms, which increases the heavy metals toxicity to them.

Key words: sediment, heavy metals, aeration, release