附载二氧化钛光催化降解水中对氯苯胺(PCA)

Photocatalytic Degradation of p-Chloroaniline in Water on Immobilized TiO_2

以紫外灯为光源 ,附载在镍网上的 Ti O2 为催化剂 ,研究水中 PCA光催化降解动力学行为和机理 .结果表明 ,PCA的降解符合准一级动力学方程 ;初始 p H4～ 1 1对其反应速率影响较小 ;增大氧气浓度能加快 PCA的降解和脱氯速率 ;外加电位能大幅度提高 PCA的降解速率 .通过 GC- MS技术确定其降解中间产物主要有苯胺、硝基苯、对氯硝基苯、偶氮苯、4,4′-二氯偶氮苯等 ,它们最终矿化为 NH+4、Cl-、NO- 3 和 CO2 .光催化能有效地降解 PCA但其矿化比降解需要更长的时间 .

The photocatalytic degradation kinetics and mechanisms of p chloroaniline (PCA)were investigated with UV as light source and titanium dioxide immobilized on nickel as catalysts.The results showed that the kinetic of photocatalytic degradation of PCA fitted quasi first order equation.The effect of pH in the range of 4～11 on the photocalytic degradation of PCA was small and the increase of oxygen concentration can accelerate the degradation of PCA and the formation of chloride ions.The degradation rate can be improved largely by imposing external bias potential.The main immediate products of PCA were identified through GC MS as aniline,nitrobenzene,4 chloronitroaniline,azobenzene,4,4′ dichloroazobenzene etc,which were mineralized to NH + 4、Cl -、NO - 3 and CO 2.PCA can be degraded but its mineralization needs much longer time than disappearance.