海泡石修复重金属Pb、Zn、Cd复合污染的土壤

Study on remediation effect of sepiolite on Pb,Zn and Cd compound contaminated soil

为研究海泡石对重金属Pb、Zn、Cd复合污染土壤的修复效果,通过盆栽实验,分析了海泡石对植物生物量,植物体内重金属浓度、P浓度以及土壤中重金属形态的影响。结果表明:重金属污染土壤中添加海泡石可显著促进玉米的生长及玉米对P的吸收,抑制土壤对重金属Pb、Zn、Cd的吸收。海泡石可显著降低土壤可交换态重金属浓度,增加碳酸盐结合态、铁锰氧化态、有机物结合态和残渣态重金属浓度,从而抑制植株对重金属的吸收,有效阻隔重金属在土壤-植物系统内的迁移。该物质具有较大的比表面积和较强的吸附能力,对重金属离子的吸附属于表面络合吸附和离子交换吸附,对重金属复合污染土壤具有较好的修复效果。

Aimed at studying the effect of sepiolite on remediation of Pb,Zn,Cd combined heavy metals contaminated soils,this paper describes pot experiments carried out to analyze the effect of sepiolite on biomass,heavy metals concentration and P concentration of plant.The results show that adding sepiolite in the heavy metal contaminated soil results in remarkable improvement in the growth and phosphorus absorption of maize,and decrease in the absorption of heavy metal Pb,Zn and Cd;sepiolite can greatly decrease the concentration of heavy metal exchangeable form,and increase the carbonate-bound,Fe-Mn oxides-bound,organic matter combined and residual matter,which shows that sepiolite can transform the available state of heavy metal into other form,decrease the maize absorption of heavy metal,and effectively barrier the migration of heavy metal in the soil-plant system.Sepiolite has much larger specific surface area and adsorption capacity,indicating that ion exchange and surface complex are key adsorption forms of sepiolite for absorbing heavy metal.Sepiolite has very good repairing effect on the heavy metal compound contaminated soil.