镉污染底泥电动修复影响因素研究

Study on influence factors of electrokinetic remediation of cadmium contaminated sediment

以镉(Cd)含量为2mg/kg污染底泥为研究对象,使用电动修复技术对污染底泥中的Cd进行脱除。研究了不同电极板间电压、化学增强剂种类以及电极材料对体系电流、温度、电导率、底泥含水率以及重金属含量的变化,试验结果表明:使用阳离子聚丙烯酰胺(CPAM)作为化学增强剂,使用多孔碳作为电极,极板间电压30V,同时在0.05MPa的压力下进行抽滤,底泥含水率在5h内由75%下降到34.17%,重金属镉含量由2mg/kg下降到0.178mg/kg,脱除率达到91.12%,修复后的底泥中镉的含量满足《土壤环境质量标准》(GB 15618-1995)中对镉含量的一级标准要求,达到了对污染底泥脱水过程中脱除重金属的目的。

Taking contaminated sediment with a cadmium(Cd)content of 2 mg/kg as the research object,we used electrokinetic remediation technology to remove the Cd in the contaminated sediment.we investigated the influences of different voltages between electrodes,types of chemical enhancers,and electrode materials on the current,temperature,conductivity,sediment moisture content,and heavy metal content.The experimental results showed that:with cationic polyacrylamide(CPAM)as chemical enhancer,porous carbon as electrode,electrode voltage of 30 V,and suction filtration at pressure of 0.05 MPa,the sediment moisture content was decreased from 75%to 34.17%in 5 hours,heavy metal cadmium content was decreased from 2 mg/kg to 0.178 mg/kg with a removal rate of 91.12%,and the content of cadmium in the remediated sediment met the first-level standard for cadmium in GB 15618-1995 Soil Environmental Quality Standard.It could realize the purpose of removing heavy metals during the dewatering process of the contaminated sediment.