鼠李糖脂洗脱氯丹和灭蚁灵污染场地土壤的工艺参数

优化了鼠李糖脂洗脱氯丹、灭蚁灵污染土壤的工艺条件,为开展有机氯农药污染场地土壤洗脱修复工程实践提供科学依据和技术参数。实验结果表明,随着洗脱剂———鼠李糖脂浓度的增加,氯丹和灭蚁灵的洗脱量呈现先增加后降低的趋势;洗脱时间和液固比对洗脱效果的影响趋势与浓度相同;在0~120 r/min范围内,氯丹和灭蚁灵洗脱量随着搅拌速度的增加而增大,80、120和200 r/min的洗脱量间差异不显著;单次洗脱量随洗脱次数的增加而降低,累计洗脱量则逐渐增大。综上所述,氯丹、灭蚁灵污染场地土壤鼠李糖脂洗脱的适宜工艺参数为鼠李糖浓度10 mmol/L,搅拌速度80 r/min,固液比1∶10,洗脱时间20 min,洗脱3次。

Optimum parameters of rhamnolipid-washing for soils contaminated by chlordane and mirex

Parameters for washing chlordane and mirex-contaminated soil with rhamnolipid were optimized through batch experiments. With an increase in rhamnolipid concentration, the washed chlordane and mirex increased at first and then reduced. The influences of washing time and ratio of rhamnolipid solution volume and soil weight on washing efficiency were similar to that of rhamnolipid concentration. The washed chlordane and mirex increased with an increase in stirring speed within a range of 0 to 120 r/min. There were no significant differences in the washed chlordane and mirex among the treatments with 80, 120 and 200 r/min. The washed chlordane and mirex declined with an increase in washing times, and the total washed chlordane and mirex were reverse. The optimum parameters for washing chlordane and mirex-contaminated soil with rhamnolipid are 10 mmol/L rhamnolipid, 80 r/min of stirring, 1:10 of soil weight to rhamnolipid solution volume, 20 min of washing for three times. The results can inform engineering application of chlordane and mirex-contaminated soil washing with rhamnolipid.