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污泥中重金属污染是影响污泥资源化利用的重要因素,而重金属的迁移性直接决定了堆肥产品的生物安全性。为研究蒙脱石对堆肥过程中重金属钝化效果及腐熟度的影响,实验以菌菇渣和猪粪为调理剂,蒙脱石为钝化剂,进行脱水污泥高温好氧堆肥。结果表明,不含钝化剂的堆肥过程中,Cu和Pb的可交换态含量增加,迁移性增强;而添加蒙脱石的堆肥化能有效抑制重金属的活化,当钝化剂的添加量为7.5%时钝化效果最好,对Cu、Pb和Zn的钝化效果分别为30.6%、38.3%和19.6%。同时,添加蒙脱石可使堆体的高温期(>50℃)维持6 d,最高温度达65℃,种子发芽指数达90%以上,堆体完全腐熟,达到堆肥无害化标准。
Heavy metal pollution in sludge is an important factor affecting the utilization of sludge, and the migration of heavy metals directly determines the biological safety of composting products. In order to study the effect of montmorillonite on the passivation effect and maturity of heavy metals in composting process, experiments were carried out with mushroom residue and pig manure as the conditioning agent and montmorillonite as the passivation agent to carry out high temperature aerobic composting of dewatered sludge. The results showed that in the composting without passivating agent, the exchangeable content of Cu and Pb increased, and the migration increased. However, the composting of montmorillonite could effectively inhibit the activation of heavy metals. When the addition amount of passivating agent was The passivation effect was the best at 7.5%, passivation of Cu, Pb and Zn were 30.6%, 38.3% and 19.6% respectively. At the same time, the montmorillonite can keep the high temperature period (> 50 ℃) of the pile for 6 days, the highest temperature reaches 65 ℃, the seed germination index reaches more than 90%, and the pile is completely decomposed to reach the standard of composting harmlessness.