石墨烯-二氧化钛电活性膜降解对氯间二甲苯酚研究

Study on parachlormetaxylenol degradation by rGO-TiO_(2) electroactive membrane

研究了石墨烯-二氧化钛电活性膜(rGO-TiO_(2)EM)降解对氯间二甲苯酚(PCMX)的机理及其出水对水环境和饮用水的安全性,采用有机-肼还原和真空抽吸法制备rGO-TiO_(2)EM,分析TiO_(2)添加量对rGO-TiO_(2)EM降解能力的影响,并对其降解PCMX的影响因素、活性物质作用、反应动力学和生物毒性变化进行研究.结果表明,在rGO-TiO_(2)EM中,TiO_(2)与GO质量比应小于1:5;在停留时间为6.78 min,电流密度为4.42m A·cm^(-2),通量为132.64 L·m^(-2)·h^(-1),PCMX初始浓度为10 mg·L^(-1)的初始条件下,PCMX去除率可达82.6%,说明了rGO-TiO_(2)EM的高效性;随着TiO_(2)添加量的增加,PCMX的降解效率和副产物生成量下降,然而降解产物毒性上升,可知生成的副产物生物毒性均低于PCMX本身,对水环境和饮用水具有安全性;提高r GO-TiO_(2)EM运行过程中单位体积水量的电能投入不仅能提高降解效果,还能减少副产物的生成,保证水环境和饮用水的安全;rGO-TiO_(2)EM降解PCMX主要的机理为直接反应.综上所述,rGO-TiO_(2)EM方法具有高效、副产物较少及环境和饮用水安全风险较低等特点,是值得进一步研究和应用的方法.

To investigate the mechanisms and safety risks in water environment and drinking water of parachlormetaxylenol(PCMX)degradation by rGO-TiO_(2)electroactive membrane(rGO-TiO_(2)EM),organism-hydrazine reduction method and vacuum pumping method were applied for rGO-TiO_(2)EM preparation;effects of catalytic performance varied with addictive amount of TiO_(2)were studied;influence factors,action of active species,apparent reaction kinetics and biotoxicity were illustrated. The results showed that mass ratio of TiO_(2)and GO should be less than 1:5 in preparation of rGO-TiO_(2)EM. When HRT was 6.78 min,current density 4.42 mA·cm^(-2),membrane flux 132.64 L·m^(-2)·h^(-1),PCMX initial concentration 10 mg·L^(-1),degradation rate was 82.6%,which illustrated high efficiencies of rGO-TiO_(2)EM. With increasing amount of TiO_(2),degradation performances and by-products generation diminished,but biotoxicity ascended,therefore the by-products were hypotoxicity than PCMX and security for water environment and drinking water.Improving electrical energy in a unit quantity of water could not only increase degradation effect,but also reduce byproducts and ensure safety for water environment and drinking water. The degradation of PCMX by rGO-TiO_(2)EM were mainly dominated by direct reactions. Above all,rGO-TiO_(2)EM method was characterized as higher efficiency,less by-products,and lower safety risk for water environment and drinking water,therefore it was worthy to be studied and applied.