电芬顿体系中氧传质/还原过程及其调控方法研究

In-situ preparation of H2O2 as an oxidant with oxygen from the air and H2O in the waste water is a prerequisite for Electro Fenton (E-Fenton) degradation of organic pollutants. In this process, the oxygen utilization efficiency is extremely low, and thereby the energy consumption of the oxygen supply system occupies over 50% of the total energy consumption of the system. The efficiency of oxygen transfer and reduction to generate H2O2 is the key to improve the efficiency of energy utilization in E-Fenton system. This project intends to use microelectrode system to investigate dissolved oxygen consumption in diffusion layer on the surface of the electrode and mass transfer rate attached, so as to establish an electrochemical evaluation method for spatial distribution of dissolved oxygen. Ordered Mesoporous Carbon（OMC） materials will be firstly prepared, followed with grafting, coating and etching procedures to optimize the size of oxygen-transferring pore channels and hydrophobicity of the pore surface in the surficial region of carbon-based electrode; Metal-organic Framework (MOF) electrode catalyst through hydrothermal synthesis method will be fabricated to further improve the current efficiency of the oxygen reduction process to obtain H2O2. Continuous-flow E-Fenton system of high-efficiency energy utilization will be constructed, afterwards phthalic acid esters (PAEs) will be employed as the model pollutants to examine energy utilization efficiency of our E-Fenton system. The fruits of this project are expected to serve as a basis for breaking through the bottleneck of energy consumption of current E-Fenton water treatment process, which means great theoretical value and practical significance attached to this research.

电芬顿（E-Fenton）降解有机污染物过程的前提是利用空气中的氧和废水中的水分子原位制取氧化剂H2O2。该过程氧的利用效率极低，导致曝气供氧能耗占体系总能耗的50%以上。氧的传质及还原生成H2O2的效率是提高E-Fenton体系能量效率的关键。本项目采用微电极系统研究电极表面扩散层溶氧传质速率，从而建立溶氧空间分布的电化学评价方法；制备块体有序多孔碳材料，再通过嫁接、涂敷、刻蚀等方法，优化孔道尺寸及亲疏水性，获得最佳的氧传质通道；通过水热合成法，制备出有机金属骨架（MOF）电极催化剂，进一步提高氧还原产生H2O2的电流效率；构建能量高效利用的连续流E-Fenton体系，以邻苯二甲酸酯（PAEs）为模型污染物，考查E-Fenton体系的能量利用效率。本项目结果有望为突破E-Fenton水处理工艺的能耗限制瓶颈提供技术手段和奠定理论基础，有重要的理论价值和实际意义。

本项目获得了具有易吸附溶氧并有利于氧传质的有序介孔结构，有优良选择性的氧还原催化剂，并适合于实际E-Fenton系统运行的块体碳电极，从而整体降低了E-Fenton系统能耗。揭示E-Fenton反应体系电极表面微环境中O2传质/还原的动力学规律和途径，为E-Fenton反应体系O2还原电极的设计提供理论指导和直观评价标准。构建了小型化连续流E-Fenton反应体系降解PAEs，研究PAEs降解的动力学规律和降解途径，为E-Fenton反应体系的实用化奠定理论基础。