Liu Jialu, Liu Zhehua, Zhang Fengjun, Su Xiaosi, Lyu Cong
Key Lab of Groundwater Resources and Environment, Ministry of Education, Jilin University, No. 2519, Jiefang Road, Changchun 130026, China E-mail:
Institute of Water Resources and Environment, Jilin University, Changchun 130026, China.
Water Sci Technol. 2017 Apr;75(7-8):1794-1803. doi: 10.2166/wst.2017.052.
This study investigates the interaction of persulfate with soil components and chlorinated volatile organic compounds (CVOCs), using thermally activated persulfate oxidation in three soil types: high sand content; high clay content; and paddy field soil. The effect of soil composition on the available oxidant demand and CVOC removal rate was evaluated. Results suggest that the treatment efficiency of CVOCs in soil can be ranked as follows: cis-1,2-dichloroethene > trichloroethylene > 1,2-dichloroethane > 1,1,1-trichloroethane. The reactions of soil components with persulfate, shown by the reduction in soil phase natural organics and mineral content, occurred in parallel with persulfate oxidation of CVOCs. Natural oxidant demand from the reaction of soil components with persulfate exerted a large relative contribution to the total oxidant demand. The main influencing factor in oxidant demand in paddy-soil-persulfate systems was natural organics, rather than mineral content as seen with sand and clay soil types exposed to the persulfate system. The competition between CVOCs and soil components for oxidation by persulfate indicates that soil composition exhibits a considerable influence on the available oxidant demand and CVOC removal efficiency. Therefore, soil composition of natural organics and mineral content is a critical factor in estimating the oxidation efficiency of in-situ remediation systems.
本研究利用热活化过硫酸盐氧化法，研究了过硫酸盐与三种土壤类型（高砂含量、高粘土含量和稻田土壤）中的土壤成分及氯代挥发性有机化合物（CVOCs）之间的相互作用。评估了土壤组成对有效氧化剂需求量和CVOC去除率的影响。结果表明，土壤中CVOCs的处理效率排序如下：顺式-1,2-二氯乙烯＞三氯乙烯＞1,2-二氯乙烷＞1,1,1-三氯乙烷。土壤成分与过硫酸盐的反应表现为土壤相中天然有机物和矿物质含量的减少，这与过硫酸盐对CVOCs的氧化反应同时发生。土壤成分与过硫酸盐反应产生的天然氧化剂需求量对总氧化剂需求量的相对贡献较大。稻田土壤-过硫酸盐体系中氧化剂需求量的主要影响因素是天然有机物，而不是像暴露于过硫酸盐体系的砂土和粘土类型那样是矿物质含量。CVOCs与土壤成分在过硫酸盐氧化反应中的竞争表明，土壤组成对有效氧化剂需求量和CVOC去除效率有显著影响。因此，天然有机物和矿物质含量的土壤组成是估算原位修复系统氧化效率的关键因素。
