微波强化铁铜基生物炭活化过硫酸钠对PCBs污染场地的修复机理研究

电子垃圾拆解区、变压器搬迁场地甚至部分城市土壤多氯联苯(PCBs)污染严重，是当前亟需解决的环境问题。以PCB28、PCB153为研究对象，采用模拟废水试验，通过分析活性氧种类与浓度、持久性自由基（PFRs）浓度与Fe/Cu价态，探索微波（MW）与铁铜基生物炭（Fe/Cu@BC）对过硫酸钠（SPS）的活化机制，分析MW对PCBs降解反应活化能及降解反应速率常数的影响，解析MW、Fe/Cu@BC与SPS协同作用机制；采用硅藻土模拟实际土壤，在密闭体系中分析PCBs在MW-Fe/Cu@BC-SPS体系下的吸附、解吸、挥发、降解与固定化过程，监测降解产物，研究PCBs降解途径和降解动力学，探索PCBs组分之间及与土壤有机质之间的竞争降解机制，揭示MW-Fe/Cu@BC-SPS体系对PCBs污染土壤的修复机理；在此基础上，通过处理实际污染土壤，研究PCBs降解的关键微环境影响因素，验证修复机理。

Polychlorinated biphenyls (PCBs) have been widely used in the last decades in China, and a large amount of discarded capacitors were buried in caves. This improper disposal practice has led to serious leakage of PCBs into the soil, which poses great risk to the environment and human health. To understand the synergistic mechanisms of microwave,Fe-Cu-biochar and sodium persulfate process, the reactive oxygen species and concentrations, the persistent free radicals in biochar, the valence states of iron and copper, the reaction rate constant and the activation energy of PCBs (PCB28 and PCB153 ) degradation in the four systems(single microwave, single Fe-Cu-biochar, single sodium persulfate and MW-Fe/Cu@BC-SPS system) will be comparatively studied. By simulated soil pollution in a sealed vial, the adsorption, desorption, volatilization, degradation and immobilization of PCBs in the MW-Fe/Cu@BC-SPS system will be studied. To reveal the remediation mechanism , the degradation products and their kinetics will also be studied. Furthermore, the effects of the physical and chemical properties of soil on PCBs removal will be studied to reveal the process and mechanism of main exogenous controllable factors in remediating PCBs-contaminated soil, based on which, the MW-Fe/Cu@BC-SPS system will be built up to treat PCBs-contaminated sites. We wish to provide a new idea of chemical remediation for PCBs contaminated soil.