猪粪降解液改性膨润土应用于修复Cu污染土壤的影响因素研究

Influence Factors of Application of Na-bentonite Modified by Pig Dejecta's Degradation in the Remediation of Cu-contaminated Soils

采用猪粪降解液改性钠基膨润土,以褐土、潮土为供试土壤,分别加入200 mg kg-1 Cu模拟污染土壤,从改性钠基膨润土、培养时间、施入量、施入方式、土壤水分含量、Cu迁移距离等5个方面研究其应用于钝化修复Cu污染土壤的影响。结果表明:钠基膨润土改性后对土壤中Cu有较好的钝化能力。随着其施入量的增加,褐土、潮土中DTPA-Cu含量逐渐降低,最佳施入量为土壤重量的1.5%,最佳土壤水分含量为70%左右。施入改性钠基膨润土可使褐土和潮土中黑麦草地上部的生物量分别增加55.4%～76.5%,地上部Cu含量降低9.15%～13.3%,采用包施和混施两种施入方式均能降低土壤中DTPA-Cu含量,且两者无显著差异。

With cinnamon and fluvo-aquic soils,the effects of modified Na-bentonite on restoration and paasivation of Cu contamination were studied in the following 5 aspects： incubation time,application rates,application methods,,soil moisture and Cu migration distance.Soils amended with 200 mg Cu kg-1 were used as Cu contaminated soils.The results showed that the content of DTPA-Cu in Cinnamon soil and Fluvo-aquic soil decreased with the increase of modified Na-bentonite application rate.The optimal application rate was 1.5% of the soil,and the optimal soil miosure was about 70%.The ryegrass shoot biomass in Cinnamon soil and Fluvo-aquic soil increased by 55.4%~76.5% compareing to control（non-Na-bentonite modified） and the Cu uptake of ryegrass decreased by 9.15~13.3%,respectively.The content of DTPA-Cu in soils decerased as the modified Na-bentonite being wrapped by nylon net or commixed with soil,and no significant difference was observed in between.