土壤组分对四氯乙烯吸附解吸行为的影响  

Effects of Soil Compositions on Sorption and Desorption Behavior of Tetrachloroethylene in Soil

作　　者：胡林[1] 邱兆富[1] 何龙[1] 窦颖[1] 吕树光[1] 隋倩[1] 林匡飞[1] 

机构地区：[1]华东理工大学资源与环境工程学院,国家环境保护化工过程环境风险评价与控制重点实验室,上海200237

出　　处：《环境科学》2013年第12期4635-4641,共7页Environmental Science

基　　金：环境保护公益性行业科研专项(201109013);上海市自然科学基金项目(12ZR1408000)

摘　　要：吸附和解吸作用是影响四氯乙烯（PCE）在土壤环境中迁移、归趋的主要过程．采用总有机碳（TOC）含量为2．23％的原土及经H2O2、375℃、600℃处理后所得的3种土样为吸附剂，通过批量平衡实验，考察了TOC含量、软碳、硬碳、初始液相PCE浓度c0等因素对PCE吸附解吸行为的影响．结果表明，当反应温度为16℃且cn为5～80mg·L^-1时，Freundlich方程能较好地拟合PCE在土样中的吸附及解吸等温线（r2〉0．96）；原土对PCE的吸附以土壤有机物（SOM）的贡献率（〉60％）为主，且硬碳是其主要影响因素；原土中SOM与矿物质对PCE的解吸贡献率相当，但在SOM对PCE解吸的贡献率中，软碳占80％以上；硬碳对PCE的吸附贡献率以及软碳和矿物质的解吸贡献率随c0的增加而升高．PCE在4种土样中都表现出一定的吸附解吸异质性，且硬碳是导致原土异质性的主要原因．Sorption and desorption play an important role in the transport and the fate of tetrachloroethylene （PCE） in soil. In order to examine influences of different soil compositions on PCE sorption-desorption, equilibrium batch experiments were carried out using four sorbents （natural soil with 2.23% total organic carbon （TOC）, H2 O2 -treated soil, 375℃-treated soil and 600℃-treated soil） with different initial PCE liquid concentrations （co ）. The effects of main parameters （TOC, soft carbon, hard carbon, minerals, co ） on PCE sorption-desorption were investigated. At 16℃ , when co was increased from 5 to 80 mg·L-1 , the results showed that sorption and desorption isotherms of PCE on four sorbents can be best described by the Freundlieh model （r2 〉 0. 96）. The sorption contribution rate of SOM was higher than 60% in natural soil, and hard carbon was the main influencing factor,while the desorption contribution rate of SOM was close to that of minerals in natural soil, and soft carbon accounted for more than 80% in the total desorption contribution rate of SOM. In addition, the higher the co , the higher the sorption contribution rate of PCE in hard carbon and desorption contribution rate of PCE in soft carbon and minerals were. Moreover, desorption of PCE from four sorbents exhibited hysteresis, and hard carbon played a remarkable role in the hysteresis of natural soil.

关 键 词：四氯乙烯 土壤吸附 解吸 有机碳 矿物质 

分 类 号：X131[环境科学与工程—环境科学]