亚硝基自由基介导的光/电化学降解全氟化合物新策略及机理研究

As a new kind of emerging POPs, perfluorinated compounds (PFCs) have high chemical stability and biological inertness. Owing to the abundant tightly-bonded fluorine atoms to carbon with high bond strength, PFCs could not be efficiently removed with most conventional degradation technologies, and even Fenton’s reagents. This project aims to develop a novel strategy of nitrogen dioxide dadicals mediated photo/electrochemical degradation of PFCs by using the UV-photolysis /electrolysis of nitrate aqueous solution, i.e. UV/NO3- and EC/NO3- system. Nitrate widely exists in surface water, under UV irradiation or electrolysis of surface water, some reactive nitrogen species can be generated. Through the introduction of hydroxyl radical scavenger, or different co-reaction agent, the types and quantities of active species under UV/NO3- or EC/NO3- system can be adjusted, leading to a high amount of nitrogen dioxide radical (•NO2) generated. The generated •NO2 could then efficiently withdraw electrons from PFCs to produce corresponding PFCs radical and thus finally the efficient degradation and even complete mineralization of PFCs can be realized. The photochemical and electrochemical degradation characteristics of PFCs will be investigated in detail under UV/NO3- or EC/NO3- system by adjusting the related experimental parameters and the feasibility of the electrochemical single/double cell. The active species generation, active species types and their formation will be investigated systematically to disclose the interaction mechanism and pathway on nitrogen dioxide radicals mediated photo/electrochemical degradation of PFCs. It is expected to establish a novel strategy based on nitrogen dioxide radicals mediated photo/electrochemical remediation of pollutants. This project could provide the theoretical support for the development of green and efficient pollution control technology.

全氟化合物（PFCs）是一类新兴的持久性有机污染物，化学稳定性高且具有生物惰性，很难被传统高级氧化技术或Fenton试剂氧化。本申请旨在以深度降解与完全矿化PFCs为目标，利用自然界水质中广泛存在的硝酸盐在紫外光辐射或电解作用下可裂解产生活性氮物种的特性，即以UV/NO3–或EC/NO3–光或电化学为具体研究体系，引入羟基自由基捕获剂或协同共反应剂，促进亚硝基自由基的产生，调控活性物种的种类、生成速率、生成量，诱导亚硝基自由基与PFCs高效电荷传递，实现深度降解甚至是完全矿化PFCs。优化光、电化学反应体系实验参数，调控电化学电解单池或双池装置，系统研究光化学或电化学降解PFCs的特性，深入分析活性物种生成和消亡规律，探究并揭示•NO2介导的PFCs降解的途径和机理。建立基于亚硝基自由基介导的污染物光/电化学治理和修复的新策略，为发展高效的PFCs污染控制技术提供理论和技术支持。

全氟化合物（PFCs）是一类新兴的持久性有机污染物，化学稳定性高且具有生物惰性，很难被传统高级氧化技术或Fenton试剂氧化。本项目旨在以深度降解与完全矿化PFCs为目标，利用自然界水质中广泛存在的硝酸盐在紫外光辐射或电解作用下可裂解产生活性氮物种的特性，先后以UV/NO3–或UV/FeNO3或EC/PS等光或电化学为具体研究体系，着重研究了氮活性物种（RNS）亚硝基自由基的产生，并探究了RNS与Fe（III)/Fe(II)循环的协同效应。以调控活性物种的种类、生成速率、生成量，诱导亚硝基自由基与PFCs高效电荷传递，实现深度降解甚至是完全矿化PFCs。优化光、电化学反应体系实验参数，调控电化学电解单池或双池装置，系统研究光化学或电化学降解PFCs的特性，深入分析活性物种生成和消亡规律，探究并揭示•NO2介导的PFCs降解的途径和机理。建立基于亚硝基自由基介导的污染物光/电化学治理和修复的新策略，为发展高效的PFCs污染控制技术提供理论和技术支持。