重度滴滴涕污染土壤低温等离子体修复条件优化研究

Optimizing Remediation Conditions of Non-thermal Plasma for DDTs Heavily Contaminated Soil

采用介质阻挡放电产生的低温等离子体对重度滴滴涕(DDTs)污染土壤进行修复处理实验,主要研究了土壤性质参数(土壤粒径和土壤含水量)和设备工作参数(放电功率、处理时间和放电气氛)对DDTs去除的影响.结果表明,采用介质阻挡放电产生的低温等离子体对土壤中的DDTs具有较好的去除作用,去除率随着处理时间的增加而升高.当处理时间增加至20min时,DDTs的去除率为95.3%～99.9%.同时确定优化条件为:放电功率1 kW、处理时间20 min、空气放电气氛、土壤粒径0～0.9 mm以及土壤含水量4.5%～10.5%.研究结果还表明,o,p'-DDE可能是o,p'-DDT氧化脱氯脱氢的中间产物.

A series of experiments were carried out in a non-thermal reactor to remove DDTs in heavily contaminated soil by dielectric barrier discharge（DBD）.The study aims to investigate the effects of soil properties（including soil particle size and soil water content） and equipment working parameters（e.g.the plasma power,the processing time and discharge atmosphere） on the removal of DDTs from soil.The results showed that DDTs in soil were significantly degraded by the non-thermal plasma produced by dielectric barrier discharge.Removal rate of DDTs increased with increasing processing time.The removal efficiency of DDTs ranged from 95.3% to 99.9% in 20 minutes.The optimum conditions were as follows：1 kW of the plasma power,20 minutes of processing time in air discharge atmosphere,0-0.9 mm soil particle size and 4.5%-10.5% of soil moisture content.The results also showed that o,p′-DDE might be the intermediate dechlorination and dehydrogenation product of the o,p′-DDT after the oxidization.