【摘要】 为了分析Fe3+参与TiO2的反应机理及微污染物的矿化效果,研究了Fe3+辅助TiO2光催化氧化降解磺胺嘧啶(SD).通过TiO2悬浮液中预添加FeCl3和既定的时间取样并测定SD浓度的方式,分析了Fe3+参与TiO2催化降解反应后的效能、SD的降解反应动力学和SD的矿化效果,探讨了溶液中Fe3+与TiO2之间可能存在的作用机理.结果表明,光催化TiO2/Fe3+降解SD的效果远好于单独使用TiO2或Fe3+催化降解时的效果.SD的初始浓度在20～80mg/L时,其降解过程遵守准一级降解动力学模型.TiO2悬浮液中预添加Fe3+能够提高SD的矿化率.Fe3+参与TiO2光催化降解反应的机理可能是部分Fe3+承担着TiO2的电子受体,降低了TiO2的电子-空穴复合的程度,因而增加了溶液中羟自由基的产率,而羟自由基产率增加强化了溶液中SD的降解.更多还原

【Abstract】 In order to explore the reaction mechanism of Fe3+ and the mineralization effect of the micropollutant,Fe3+-assisted photocatalytic oxidation of sulfadiazine(SD) in the TiO2 suspended solution is investigated.The effect of Fe3+participation,the degradation kinetics of SD,the effect of SD mineralization and the possible mechanism of Fe3+ participation in TiO2 suspension are analyzed by adding FeCl3,taking samples at a given time and determining the SD concentration.Results indicate that the degradation of SD catalyzed by TiO2/Fe3+ is faster than that catalyzed by TiO2 or Fe3+separately.The photocatalytic degradation of SD follows the pseudo-first-order kinetics model in a range of 20 to 80 mg/L of initial concentration.The mineralization rate of SD can be enhanced by the addition of Fe3+ in the TiO2 suspended solution.The mechanism of the rapid degradation of SD is proposed,which indicates that Fe3+ adsorbed on the surface of TiO2 particles acts as an electron acceptor.The amount of recombining electron-hole pairs decreases,and the amount of hydroxyl radicals increases.The increased hydroxyl radical strengthens the degradation of SD in the TiO2/Fe3+ suspended solution.更多还原