Fenton试剂氧化去除土壤洗脱液中DDTs的研究

Oxidation Removal of DDTs in Soil Washing Effluent by Fenton Regent

以表面活性剂Tween80对DDTs污染土壤的洗脱液为目标,研究了Fenton试剂对洗脱液中DDTs的氧化去除效果及影响因素。结果表明,对于浓度为50 mg/kg的DDTs的单一污染土壤,Tween80显示出较好的洗脱效果,2.0 g/L的Tween80对DDTs的洗脱率可达到30%以上。Fenton试剂可以有效处理DDTs污染土壤的洗脱液,Fe^(2+)浓度、H_2O_2添加量、pH值、温度以及反应时间均对DDTs的去除率产生一定的影响。综合考虑处理效率与处理成本,其最佳反应条件为:Fe^(2+)浓度为20 mmol/L,H_2O_2添加量为10 mL/L,pH值为3,温度为30℃,反应时间为30 min,该条件下单一污染土壤洗脱液中DDTs的去除率均达到70%以上;对于DDTs复合污染土壤的洗脱液,该条件下Fenton试剂对DDTs的总去除率可达到50.2%。研究结果表明利用Fenton试剂氧化处理DDTs污染土壤洗脱液是可行的。

The oxidation removal efficiency of DDTs from Tween80 washing effluent of contaminated soil by Fenton regent was investigated in this study. The removal rates of DDTs from soil increase gradually with the increase in concentration of Tween80, and the highest removal rates were more than 30% when Tween80 is 2.0 g/L. Fenton regents were effective on oxidation removal of DDTs from washing effluent of DDTs contaminated soil, and the factors including concentration of Fe2＋,dosage of H2O2, pH value, reaction temperature and time were discussed to determine their effects on the removal efficiencies of DDTs. The optimal experiment conditions were the concentration of Fe2＋20 mmol/L, dosage of H2O210 mL/L, pH value 3,reaction temperature 30 ℃ and reaction time 30 min. Under these conditions, the removal rates of DDTs by Fenton regent were more than 70% from washing effluent of single contaminated soil and that was 50.2% from washing effluent of combined contaminated soil with six DDTs. The above results indicate that Fenton regent has the workability to apply to washing effluent of DDTs-contaminated soil.