关键词: 堆肥, 重金属, 钝化, 生物有效性

Abstract: With fast development of large-scale farming, owing to the heavy application of animal food additives containing heavy metals, large amounts of heavy metals, such as Cu, Zn, Pb, Cd and so on, were discharged into the environment with animal manure. Composting is a major method for the resource utilization of animal manure. Previous studies showed that heavy metals contained in the animal manure could be passivated by the huminification effect of composting, and the biological activities of them could also be reduced during composting. The research progress of heavy metals content and chemical state variations in animal manure during the composting process, heavy metal immobilization mechanism, as well as the effects of different immobilization agents on heavy metals immobilization, were reviewed in this paper. Furthermore, the current defects and focus of further research on the research of heavy metal immobilization were also proposed. Current results showed that, the concentrations of heavy metals mainly increased during the composting process, By means of physical adsorption, complexation and microbial enhancement, the chemical state of heavy metals could be transformed from unstable state to stable state Nevertheless, the immobilization mechanisms of heavy metals during the animal manure composting process are not completely understood, and the immobilization mechanisms of immobilization agents on heavy metals need further study. Moreover, novel composite material for high efficient heavy metal immobilization need to be developed.

Key words: composting, heavy metals, immobilization, bioavailability