高温堆肥与蚯蚓堆肥对城市污泥重金属形态的影响

采用高温堆肥和蚯蚓堆肥工艺，研究了城市污泥与锯末、粉煤灰或磷矿粉按不同比例混合堆肥前后重金属（Cu、Pb、Zn、Cd和As）交换态、碳酸盐结合态、铁锰氧化物结合态、有机结合态和残留态的变化。研究表明：高温堆肥和蚯蚓堆肥前后各试验污泥的重金属形态和含量呈现出不同的变化，都可以降低污泥中交换态Cu、Pb、Zn、Cd和As的含量；对于Cu和Pb，高温堆肥优于蚯蚓堆肥；对于Zn、Cd和As，蚯蚓堆肥优于高温堆肥。2种堆肥方式中，粉煤灰用量为10%的钝化效果优于20%，磷矿粉的钝化效果同粉煤灰一样。

Effects of high-temperature and earthworm composting on heavy metal speciation changes in municipal sludge

The high-temperature composting and the earthworm composting were adopted to study the changes in the exchanged state,carbonate combined state,Fe-Mn oxide combined state,organic combined state and residual state of heavy metals including Cu,Pb,Zn,Cd and As before and after the mixing of sludge,sawdust,fly ash and ground phosphate rock in different proportions.The results show that after the high temperature composting and the earthworm composting,the patterns and contents of the heavy metals in the experimental sludge emerged different changes.The two composting methods can both reduce the contents of Cu,Pb,Zn,Cd and As with exchanged state in the sludge.For Cu and Pb,the hig temperature composting is superior to the earthworm composting,but for Zn,Cd and As,the result is opposite.The inactivation effect of fly ash and ground phosphate rock in the composting process was discussed.The inactivation effect of 10% of fly ash is superior to that of 20% of fly ash in both composting methods.The inactivation effect of ground phosphate rock is same as that of fly ash.