天然有机质电子转移是沉积物中污染物转化的重要组成部分。近年研究发现，热解黑碳的石墨烯化使碳母体可直接进行电子传递，其速率是传统官能团充放电传递速率的三倍，这暗示着黑碳的作用要比预想大得多。为证实该设想，本项目利用纳米零价铁（nZVI）降解典型持久性有机污染物多氯联苯（PCBs）这一反应，通过研究黑碳吸附（抑制）与电子转移（促进）双重作用下该反应的脱氯效果，探讨沉积物黑碳电子转移对污染物降解的影响：在分析不同类型黑碳电子传递特征的基础上，一方面研究黑碳对水相中PCBs降解的影响，通过表征与产物鉴定，探讨黑碳与nZVI的作用机理；另一方面，采用外源添加法研究沉积物中黑碳对该反应的影响，结合老化态黑碳电子转移性能、解吸动力学和降解动力学，分析不同形态PCBs降解活性，建立残留预测模型。该研究不仅可以明晰沉积物黑碳在污染物化学还原反应中的作用，也将为开发高效的碳-nZVI修复材料提供新思路。

Electron transfer of natural organic matter is the basis of transformation of pollutants in sediment. Recent research found that the graphene phenomenon of pyrogenic black carbon caused direct electron transfer by the carbon matrix. Moreover, the rate of this direct electron transfer was three times higher than that of charging-discharging mechanism caused by functional groups, which implied sediment black carbon might play greater role in pollutant conversion than previous assumption. To verify this theory, our project will choose the degradation of polychlorinated biphenyls (PCBs, a typical persistent organic pollutants) by nZVI as a model to study. The efficiency of PCBs dechlorination under the adsorption (inhibition) and electron transfer (promotion) of black carbon will be investigated through the following procedures: on the basis of the analysis of electron transfer function of various black carbons produced from different precursors and temperatures, 1) investigate the influence of black carbon on the degradation of PCBs in water, and then explore the reaction between different types of black carbon and nZVI by system characterization and product identification; 2) investigate the influence of black carbon on the degradation of PCBs in sediment, and analyze the activity of different forms of PCBs and then build PCBs residual prediction model through studying electron transfer behavior of aging black carbon, desorption kinetics as well as PCBs degradation kinetics of aged black carbon. It is expected this project can not only clarify the role of sediment black carbon in the chemical reduction of pollutants, but also provide new insights in developing efficient carbon-nZVI repair materials.