外源添加膨润土对猪粪腐解中重金属含量的动态影响研究

Study on Heavy Metals Content of Pig Manure by Supplying Bentonite

以猪粪为研究对象,采用高温好氧模拟堆腐试验,研究了外源添加剂膨润土对猪粪腐解过程中重金属含量的动态变化规律。研究结果表明:高温堆肥处理后,猪粪中重金属Cu、Zn离子含量普遍升高,表现出明显的"相对浓缩效应"。堆肥处理可以一定程度上降低猪粪中重金属Cu、Zn的生物有效性,使其形态向有效性低的方向转化。外源添加膨润土明显降低了猪粪中DTPA-Cu和DTPA-Zn的含量。其对堆肥可交换态重金属Cu和Zn的钝化效果分别为63.60%和44.01%。

The paper studied the heavy metals content change of pig manure by supplying bentonite with high temperature aerobic composting.The main results were as follows： In the process of pig manure composting, concentrations of Zn and Cu increased.Composting obviously stimulated transformation of Zn and Cu into forms low in activity,thus decreasing bioavailability of the heavy metals.Bentonite was effective in reducing bioavailability of Zn and Cu.The passivation effectiveness of bentonite on exchangeable heavy mentals（Cu and Zn）Was 63.60% and 44.01%,respectively.Bentonite can be used to treat pig manure in composting to reduce the risk of heavy metal pollution of using pig manure in farmland.