Zhang Zhenguo, Zhou Zhou, Liu Xitao, Zhang Hui, Xu Hengpu, Lin Chunye, He Mengchang, Ouyang Wei
State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China.
State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China; North China Power Engineering CO., Ltd of China Power Engineering Group, Beijing 100120, China.
J Hazard Mater. 2023 Sep 15;458:131985. doi: 10.1016/j.jhazmat.2023.131985. Epub 2023 Jul 1.
Soil contamination caused by persistent organic pollutants (POPs) has been a worldwide concern for decades. With lindane-contaminated soil as the target, a mechanochemical method assisted by CaO was comprehensively evaluated in terms of its remediation performance, degradation mechanism and overall assessment. The mechanochemical degradation performance of lindane in cinnamon soil or kaolin was determined under different additives, lindane concentrations and milling conditions. 2,2-Diphenyl-1-(2,4,6-trinitrophenyl) hydrazinyl free radical (DPPH) and electron spin resonance (ESR) tests evidenced that the degradation of lindane in soil was caused mainly by the mechanical activation of CaO to produce free electrons (e) and the alkalinity of the generated Ca(OH). Dehydrochlorination or dechlorination by elimination, alkaline hydrolysis, hydrogenolysis and the subsequent carbonization were the main degradation pathways of lindane in soil. The main final products included monochlorobenzene, carbon substances and methane. The mechanochemical method with CaO was proved to also efficiently degrade lindane in three other soils and other hexachlorocyclohexane isomers and POPs in soil. The soil properties and soil toxicity after remediation were assessed. This work presents a relatively clear discussion of various aspects of the mechanochemical remediation of lindane-contaminated soil assisted by CaO.
几十年来，持久性有机污染物（POPs）造成的土壤污染一直是全球关注的问题。以林丹污染土壤为研究对象，从修复性能、降解机理和综合评价等方面对CaO辅助机械化学法进行了全面评估。在不同添加剂、林丹浓度和研磨条件下，测定了林丹在肉桂土或高岭土中的机械化学降解性能。2,2-二苯基-1-（2,4,6-三硝基苯基）肼基自由基（DPPH）和电子自旋共振（ESR）测试表明，土壤中林丹的降解主要是由于CaO的机械活化产生自由电子（e）以及生成的Ca(OH)的碱性作用。脱氯化氢或消除脱氯、碱性水解、氢解以及随后的碳化是土壤中林丹的主要降解途径。主要最终产物包括一氯苯、碳物质和甲烷。结果证明，CaO机械化学法还能有效降解其他三种土壤中的林丹以及土壤中的其他六氯环己烷异构体和持久性有机污染物。对修复后的土壤性质和土壤毒性进行了评估。这项工作对CaO辅助机械化学修复林丹污染土壤的各个方面进行了较为清晰的探讨。
