Abstract: A study was carried out using the sequential extraction method,on effect of application of heavy metals passivator on concentrations and forms of heavy metals in pig manure being composted aerobically under high temperature. Results show that after aerobic composting,concentrations of Zn,Cu,Pb,Cr,and As were increased,but the concentration of Hg was decreased significantly. Composting obviously stimulated transformation of Zn,Cu,Pb,Cr,As,and Hg,into forms low in activity,thus decreasing bio-availability of the heavy metals. Among the three heavy metal passivators,zeolit was the most effective in reducing bio-availability of Zn and Cu,sepiolite was the most effective in reducing bio-availability of Cr,and bentonite was the most effective in reducing bio-availability of Pb and Hg in pig manure. Therefore,zeolite,sepiolite and bentonite can be used to treat pig manure in composting to reduce the risk of heavy metal pollution of using pig manure in farmland.

Key words: passivator, aerobic composting, pig manure, heavy metal, bio-availability