化学淋洗联合油葵植物修复土壤中Cd

首先采用大田盆栽实验,种植油葵修复净化土壤中的Cd,再采用去离子水、柠檬酸、醋酸、EDTA、盐酸等5种单一淋洗剂,以及柠檬酸+盐酸、EDTA+柠檬酸、EDTA+盐酸等3种复合淋洗剂进行室内柱淋洗,联合去除土壤中Cd.结果表明:土壤中初始添加Cd的质量浓度分别为20mg·kg-1和50mg·kg~(-1)时,盆栽种植油葵对Cd的去除效率分别为25%和65%;在植物修复的基础上,继续采用0.04mol·L~(-1)的EDTA和0.05mol·L-1的EDTA进行淋洗,对土壤中剩余Cd的去除率分别达到83.33%和91.67%,而0.04mol·L~(-1)的EDTA+柠檬酸与0.05mol·L~(-1)的EDTA+盐酸复合淋洗剂净化能力最佳,分别达到95.92%和92.7%,且复合淋洗剂的净化效果随着土壤Cd含量的增加而增加;当土壤粒度大于150μm时,化学淋洗剂对土壤中的Cd几乎无净化作用.

Coupled Chemical Leaching with Oil Sunflower Phytoremediation Cadmium in Soil

In this research,oil sunflower was planted in cadmium contaminated soil by pot experiment.And then the same soil was added into the leaching column and eluted by different single eluting agents,such as deionized water,citric acid,acetic acid,EDTA and hydrochloric acid or compound eluting agents,such as citric acid mixed with hydrochloric acid,acetic acid,EDTA mixed with citric acid and EDTA mixed with hydrochloric acid.The results showed that the oil sunflower could remove 25% and 65% of total amount of cadmium when the initial cadmium contents in soil were 20mg·kg~(-1) and 50mg·kg~(-1),respectively.The followed experiments were tested by leaching column.The 83.33%and 91.67% of elution efficiencies were gained by 0.04mol·L~(-1)of EDTA and 0.05mol·L~(-1)of EDTA,respectively.The best elution efficiencies of 95.92%and 92.7% could be reached by using the compound eluting agents of 0.04mol·L~(-1)of EDTA+citric acid and 0.05mol·L~(-1)of EDTA+hydrochloric acid,and the elution efficiency improved with the increasing of cadmium content in soil.The elution efficiency was affected by the particle size of soil.However,there was no leaching effect when the particle size was beyond150μm.