热解污泥生物炭去除水和饱和带土壤中苯胺污染的效能及机理研究

Study of Efficiency and Mechanism of Removing Aniline Contamination from Aqueous Solution and Soil Saturated Zone by Pyrolytic Sludge Biochar

针对化工行业污染地块中存在的土壤和地下水苯胺污染问题,对比了热解污泥生物炭(Sludge-based Pyrolysis Biochar,SPB)与传统氧化剂(Fenton试剂、KMnO_(4))对水及饱和带土壤中苯胺的氧化降解效能,揭示了SPB降解苯胺的机理。结果表明:SPB(投加量为5.00和2.50 g/L)在水溶液中对苯胺(初始浓度为1.5 mg/L)的降解率达到99.9%,高于传统氧化剂(投加量为1.00和0.50 mmol/L)对水中苯胺的降解效能。饱和带土壤中苯胺浓度为150 mg/kg,SPB投加量为100 g/kg时,水相苯胺的去除效率(99.19%)优于传统氧化剂,对土相苯胺的去除效率达84.07%。SPB去除苯胺过程中,生成了^(1)O_(2)、OH·及O_(2)^(-)·等活性氧自由基,对苯胺氧化降解具有显著作用,其中,^(1)O_(2)对苯胺降解的贡献最大,约为51.3%。

Aiming at the problem of aniline pollution in soil and groundwater in contaminated plots of chemical industry,the oxidative degradation efficiency of aniline in water and saturated soil by sludge-based pyrolysis biochar(SPB)and traditional oxidants(Fenton reagent and potassium permanganate)was compared.The mechanism of aniline degradation by SPB was revealed.The results showed that the degradation rate of aniline(initial concentration was 1.5 mg/L)by SPB(dosage of 5.00 and 2.50 g/L)in aqueous solution reached 99.9%,higher than the traditional oxidants(dosage of 1.00 and 0.50 mmol/L).When the concentration of aniline was 150 mg/kg and the dosage of SPB was 100 g/kg,the removal efficiency of aqueous aniline(99.19%)was better than that of traditional oxidizing agent,and the removal efficiency of soil aniline reached 84.07%.Reactive oxygen species such as ^(1)O_(2),OH·and O_(2)^(-)·were generated during the removal of aniline by SPB,which had a significant effect on the oxidative degradation of aniline.Among them,^(1)O_(2) contributed the most to aniline degradation,about 51.3%.