土壤-零价铁体系中典型氯代有机物传质过程及表面活性剂的影响机制

污染物传质过程是零价铁（ZVI）还原降解土壤氯代有机污染物（COCs）研究的热点和难点，也是表面活性剂强化ZVI修复技术发展的可能突破点。但关于COCs在土壤-ZVI体系的传质过程仍缺乏研究，表面活性剂对传质过程的影响机理尚未明晰。本项目拟以典型COCs—2,2’,5,5’-四氯联苯（PCB-52）为研究对象，通过建立土壤-ZVI体系中PCB-52的传质过程数学模型，定量说明传质过程与降解间的关系；以不同有机质含量土壤为介质，通过不同种类和浓度的表面活性剂调控体系传质过程，利用传质过程数学模型阐明表面活性剂通过调控SOM界面分配行为对PCB-52的传质过程及还原降解的影响，并通过电镜、X射线衍射等表面分析手段揭示影响过程的机理。本研究有助于揭示ZVI降解土壤COCs的反应机制，并为COCs污染土壤风险管控和治理修复提供科学依据及理论支持。

The mass transfer process of chlorinated organic contaminants (COCs) is one of the most concerned issues in the field of zerovalent iron (ZVI) dechlorination in soil. It is probably the breakthrough to improve the surfactant-assisted ZVI technique. However, the correlation between mass transfer and dechlorination is still to be clarified, as well as the influential mechanisms of surfactants and soil organic matter (SOM) on mass transfer. Thus, in the present study, a typical COCs–2,2’,5,5’-polychlorinated biphenyls (PCB-52) is selected as the target COCs. By establishing the model of PCBs transfer in ZVI-soil system, the mass transfer of PCBs and its relation with dechlorination efficiency will be illustrated. With advanced analyzing methods such as SEM/TEM and XRD, the effects of surfactants and the associated mechanisms will also be illustrated. This research is expected to provide a convincing theoretical and practical support for the management and remediation of soils contaminated by COCs.