Clean-up method for the polluted soil sites by colloid particles and dissolved organic matter

本研究的目的是评估一种新的污染土壤净化方法的可能性，基于应用或增强胶体和溶解性有机物（DOM）通过土壤淋溶。为此，胶体和DOM通过不同结构的土壤系统的动员和运输，以及多环芳烃（PAH）吸附到不同的土壤类型进行了研究。土壤中无机胶体物质（ICM）、胶体有机碳（COC）和溶解性有机碳（DOC）三种天然成分在重复灌溉条件下的迁移和淋溶表现出明显不同的淋溶行为，在有和无连续大孔隙的土壤中表现出不同的行为。胶体动员和运输通过大孔和PAH吸附到土壤和土壤成分被发现是时间依赖性和扩散限制的过程，并提出了新的模型来描述扩散限制的胶体生成和动员和PAH吸附。外施胶体和DOM的迁移进行了研究壤土和砂土。几乎100%的胶体通过壤土浸出，而约32%的浸出和68%被捕获的沙子。胶体和示踪剂Br的运移参数比较表明，在田间尺度上，胶体在高结构壤土中的运移速度是示踪剂的3 ~ 4倍。从结果中，它建议，应用所提出的清理方法污染土壤的可能性是最现实的土壤，不是高度结构化的，但仍然有利于显着的胶体和DOM运输，低有机桑迪或粗壤土是最有前途的目标群体。但在实际应用之前，还需要进一步的中试和现场规模的研究和测试。

The purpose of this research is to evaluate the possibility of a new clean-up method for polluted soils, based on applying or enhancing colloid and dissolved organic matter(DOM) leaching through the soil. For this purpose, mobilization and transport of colloids and DOM through differently-structured soil systems, and poly aromatic hydrocarbon(PAH) sorption to different soil types were investigated. Mobilization and leaching of three natural soil constituents, inorganic colloidal matter(ICM), colloidal organic carbon(COC) and dissolved organic carbon(DOC) from a surface soil (loam) during repeated irrigation showed widely different leaching behavior and behaved differently in soil with and without continuous macropores. Both colloid mobilization and transport through macropores and PAH sorption to soil and soil constituents were found to be time-dependent and diffusion-limited processes, and new models to describe diffusion-limited colloid generation and mobilization and PAH sorption were proposed. The transport of externally applied colloid and DOM was examined for a loam soil and a sand. Almost 100% of the applied colloids leached through the loam soil, while around 32% leached and 68% was captured by sand. From the comparison of transport parameters of colloid and a tracer (Br), the velocity of colloid was 3〜4 times larger than the one of the tracer in a highly-structured loamy soil a the field scale. From the results, it is suggested that the possibility of applying the proposed clean-up method for polluted soil is most realistic for soils that are not highly-structured but still facilitates a significant colloid and DOM transport, with low-organic sandy or coarse-loamy soils being the most promising target group. But further investigation and tests at pilot and field scale are needed before any actual application.