碳气凝胶阴极用于电化学臭氧体系去除布洛芬的机理试验研究

Removal of ibuprofen by electrolysis-ozone system with carbon fiber aerogel cathode

以天然棉花为前驱物,通过直接一步热解法制备了新型碳纤维气凝胶(CFA)阴极,用于电化学臭氧技术(E-O 3-CFA),通过SEM、BET、XPS等方法对CFA进行成分和结构分析,系统地研究了E-O 3-CFA体系对水中布洛芬(IBP)的去除情况,考察了阴极材料、臭氧浓度、电流强度和初始pH值等因素的影响,分析该体系去除IBP的途径和机理,并对能耗进行计算。结果表明,CFA是一种多孔互联的三维网状结构,孔隙发达,比表面积高且表面存在丰富的含氧官能团,在电流强度为300 mA、O 3浓度为16 mg/L、未调节初始pH值的条件下,E-O 3-CFA体系对水中IBP的去除率高达97.96%,高于使用其他阴极材料的电化学臭氧体系(不锈钢阴极83.11%、活性炭纤维阴极94.78%、石墨阴极89.05%),CFA阴极的使用进一步降低了电化学臭氧体系的单位能耗(SEC=2.49 kW·h/gTOC),该体系主要通过以羟基自由基(·OH)为主的自由基路径氧化降解有机物。

A novel carbon fiber aerogel was prepared by one-step direct pyrolysis method using natural cotton as a precursor,and the electrolysis-ozone technology using CFA cathode(E-O 3-CFA)was established.The composition and structure of CFA were analyzed by SEM,BET and XPS.The removal of IBP and the main operational parameters(e.g.,cathode materials、current intensity、ozone concentration and pH)were evaluated systematically.The pathway and mechanism of IBP removal were also investigated,and the energy consumption was calculated.The results showed that CFA is a porous interconnected three-dimensional network structure with developed pores,high specific surface area and abundant oxygen-containing functional groups on the surface.The removal rate of IBP by E-O 3-CFA process was 97.96%at ozone concentration of 16mg/L,current intensity of 300 mA,and without adjusting the initial pH.It was higher than the electrolysis-ozone technology with other cathode(steel cathode 83.11%、activated carbon fiber cathode 94.78%、graphite cathode 89.05%).The IBP was mainly removed by the free radical oxidation pathway by·OH.Moreover,the specific energy consumption(SEC=2.49 kW·h/gTOC)of electrolysis-ozone technology for TOC removal was furtherly reduced by using CFA cathode.