复配淋洗剂对重金属污染土壤淋洗效果的研究

STUDY ON THE WASHING EFFECT OF COMPOUND ELUENT ON HEAVY METAL CONTAMINATED SOIL

由于实际场地中多种重金属污染物的存在。因此需要利用不同种类淋洗剂对不同重金属去除能力的差异,将2种或2种以上的淋洗剂进行组合的多步淋洗法,以解决复合污染的问题。本试验采用不同浓度的EDTA与草酸、柠檬酸与酒石酸以及FeCl 3与柠檬酸和酒石酸复配淋洗的方法对重金属污染土壤的最佳淋洗效果进行了研究,探讨了不同组合、浓度、类型条件下对重金属的去除效果。结果表明,复配淋洗效果明显优于单一淋洗效果,0.005 mol/L EDTA+0.01 mol/L草酸复配时Pb的去除率最高为96.25%,0.01 mol/L EDTA+0.02 mol/L柠檬酸复配时Cd的去除率最高为62.94%。该研究结果为今后修复重金属污染土壤提供了理论依据与数据支撑。

Due to the contaminated site soil is mostly compound contaminated soil,which contains a variety of heavy metals.Therefore,two or more types of eluents forming a multistep washing method should be combined to solve the problem of compound contamination by taking advantage of the various removal capacities of different types of eluent.In this experiment,the different concentrations of EDTA and oxalic acid,citric acid and tartaric acid,and FeCl_(3) combined with citric acid and tartaric acid were used to study the best washing effect of heavy metal contaminated soil,and different combinations,concentrations,and types of conditions were discussed.Results show that the washing effect of compound washing is significantly better than that of single washing.The maximum removal rate of Pb is 96.25%when the 0.005 mol/L EDTA+0.01 mol/L oxalic acid is compounded.The highest removal rate of Cd is 62.94%when the 0.01 mol/L EDTA+0.02 mol/L citric acid is compounded.The research results provide theoretical basis and data support for the future restoration of heavy metal contaminated soil.