Abstract：
Investigations about the remediation of Hexachlorocyclohexane (HCH), a persistent organic pollutant of global concern, have been extensively reported to treat the HCH contaminated soil. The difficulty arising due to desorption and long ageing procedures of this hydrophobic organic compound in the soil, make it necessary to exploit techniques like soil washing or addition of surfactants, for enhancing the mass transfer rate of hydrophobic compounds. However, this technique gives rise to the generation of a large quantity of waste solution containing the pollutant and various other toxic substances. Moreover, it is challenging to deal with the complex soil washing solution, and thus a follow-up treatment of such washing solution is essentially required before its discharge. This follow-up treatment could be the bioreactor system to efficiently treat the pollutant in the wash solution, thereby reducing the amount of contaminated soil that has to be treated. Among many suggested remediation methods and treatment technologies, integrated soil washing and post-treatment with the bioreactor system could be an environmentally viable method for the remediation of HCH contaminated sites. This review focuses on the soil washing procedures applied so far for the HCH contaminated soil and various factors affecting the efficiency of separation of the target pollutant. Furthermore, the environmental and reactor design-related factors are also discussed for degradation of HCH in the reactor system. Finally, advantages and environmental feasibility of this proposed combined technology and the challenges that need to be encountered are envisaged.
摘要：
关于六氯环己烷(HCH)修复的调查，全球关注的持久性有机污染物，已被广泛报道用于处理六氯环己烷污染的土壤。由于这种疏水性有机化合物在土壤中的解吸和长期老化过程而产生的困难，使其有必要利用技术，如土壤洗涤或添加表面活性剂，用于提高疏水性化合物的传质速率。然而,这种技术会产生大量含有污染物和各种其他有毒物质的废液。此外，处理复杂的土壤洗涤溶液具有挑战性，因此在其排放之前基本上需要对这种洗涤溶液进行后续处理。这种后续处理可以是生物反应器系统，以有效地处理洗涤溶液中的污染物，从而减少必须处理的污染土壤的数量。在许多建议的修复方法和处理技术中，生物反应器系统的综合土壤洗涤和后处理可能是修复六氯环己烷污染场地的环境可行方法。本综述侧重于迄今为止对六氯环己烷污染土壤应用的土壤洗涤程序以及影响目标污染物分离效率的各种因素。此外，还讨论了反应器系统中六氯环己烷降解的环境和反应器设计相关因素。最后,这种提出的组合技术的优势和环境可行性，以及需要遇到的挑战。
