两种萃取剂对土壤中砷的萃取条件优化

Optimization of extraction conditions of arsenic in soil by two extracting agents

为了探明磷酸和磷酸二氢钾对土壤中砷污染物的萃取修复效果差异,设置不同的萃取剂浓度、土液比、萃取时间,通过萃取试验,对不同条件下的砷萃取量进行测试分析。结果表明:随着萃取剂浓度的升高,单位质量的土壤砷萃取量增加,磷酸萃取剂的最佳浓度为1.5 mol·L-1,磷酸二氢钾萃取剂的最佳浓度为1.5 mol·L-1;土液比变化对土壤砷的萃取量无明显影响;对于砷含量为98.53 mg·kg-1的土壤,磷酸溶液萃取土壤砷的最佳条件为:浓度1.5 mol·L-1、土液比(g∶mL)1∶3、萃取时间1 h,磷酸二氢钾萃取剂萃取土壤砷的最佳条件为:浓度为1.5 mol·L-1、土液比(g∶mL)1∶5、萃取时间4 h。

In order to find out the effect of phosphoric acid and potassium dihydrogen phosphate solution on the extraction of arsenic pollutants in soil,different extraction concentration,soil liquid ratio,and extraction time were set up.The arsenic extraction amount under different conditions was tested and analyzed through extraction tests.The results showed that:With the increase of the extract concentration,the amount of arsenic extraction per unit soil increased,the best concentration of phosphoric acid solution was 1.5 mol·L-1,and the best concentration of potassium dihydrogen phosphate solution was 1.5 mol·L-1;The changes of soil liquid ratio had no significant effect on the extraction amount of soil arsenic.For soils with arsenic content of 98.53 mg·kg-1,the best conditions for the extraction of soil arsenic with phosphoric acid were:1.5 mol·L-1,soil liquid ratio(g∶mL):1/3,extraction time:1 h.The best conditions for the extraction of soil arsenic with potassium dihydrogen phosphate solution were:1.5 mol·L-1,soil liquid ratio(g∶mL):1/5,extraction time:4 h.