表面活性剂洗脱/类Fenton氧化对六氯苯污染黑土的处理

Treatment of hexachlorobenzene-contaminated black soil by surfactant elution and Fenton-like oxidation

以人工模拟六氯苯污染黑土土壤为对象,利用表面活性剂洗脱法和类Fenton试剂氧化法研究了土壤中六氯苯的去除效果及影响因素。结果表明,3种表面活性剂对黑土土壤中的六氯苯均有一定的洗脱效果,5.0 g·L^(-1)的Tween80、Triton X-100和SDBS对六氯苯的洗脱率分别为75.26%、67.39%和50.18%。利用类Fenton试剂对土壤洗脱液中的六氯苯进行氧化处理,其催化剂类型及浓度、氧化剂的浓度及添加方式、温度、反应时间及pH值等因素均对洗脱效果产生不同程度的影响,当Fe2(SO4)3浓度为0.08 mol·L^(-1),H_2O_2添加量为0.5 mol·L^(-1),温度为30℃,pH值为5.0,反应时间为60 min时,类Fenton试剂可氧化去除土壤洗脱液中80%左右的六氯苯。在该处理条件下,土壤洗脱液中COD的去除率可达到80%左右,洗脱液的水质及其可生化性得到了明显的改善。

The remediation of hexachlorobenzene （HCB）-contaminated black soil was investigated using surfacrant elution and Fenton-like oxidation in a laboratory. The results showed that the three suffactants could effectively remove HCB from soil,and that the removal rates of HCB from soil were 75.26% ,67.39% ,and 50. 18% , with concentrations of 5.0 g · L^-1 for Tween80, Triton X-100, and SDBS,respectively. Fenton-like oxidation was effective for removal of HCB from the soil eluent. The removal efficiency of HCB was affected by the type and dosage of catalysts, method of addition of H2O2 , reaction temperature, pH, and reaction time. The best experimental conditions were as follows：the dosage of Fe2（SO4）3 was 0. 08 mol · L^-1 ,dosage of HzO2 was 0.5 mol · L^-1 , pH was 5.0,reaction temperature was 30 ℃ ,and reaction time was 60 min. About 80% of HCB and COD were removed from the soil eluent by Fenton-like oxidation under the above given conditions. Furthermore,the water quality and biodegradability of the soil eluent were obviously improved after the Fenton-like oxidation treatment.