Cr(VI)-苯酚共存污染体系中的光催化反应研究

采用焙烧的P-25 TiO2作为光催化剂,研究了Cr(VI)-苯酚共存污染体系中Cr(VI)的光催化还原及苯酚的光催化氧化,并考察了pH值、气氛和初始浓度等对其光催化性能的影响。结果表明,Cr(VI)-苯酚共存体系中Cr(VI)及苯酚的去除率均较Cr(VI)和苯酚的单一体系高;酸性条件下有利于Cr(VI)的光催化还原,中性条件下苯酚的光催化降解率最高;气氛对Cr(VI)-苯酚共存体系中Cr(VI)的光催化还原及苯酚的光催化氧化均无明显影响;增大苯酚浓度可以有效的提高该体系中Cr(VI)的光催化还原,增大Cr(VI)浓度可以有效的提高该体系中苯酚的光催化氧化;Cr(VI)离子的光催化还原遵循L-H动力学规律,而苯酚的光催化氧化符合一级反应动力学规律。

Study on Photocatalytic Reactions in Cr(VI)-Phenol Co-existed Pollution System

Using calcined nanometer P-25 TiO2 as photocatalyst,the photocatalytic reduction of Cr(VI) and oxidation of phenol in Cr(VI)-phenol co-existed pollution systems were studied.The effects of pH values,reaction atmosphere and various initial concentrations of Cr(VI) and phenol on photocatalytic reaction performance have been investigated.The results indicate that Cr(VI) and phenol are more efficiently eliminated in Cr(VI)-phenol co-existed system than in single Cr(VI) or phenol system.The acidic solutions are favorable for the photocatalytic reduction of Cr(VI),and the optimum pH for the degradation of phenol is 7.The reaction atmosphere has negligible effect on photocatalytic redution of Cr(VI) and oxidation of phenol.The photocatalytic reduction rate of Cr(VI) increases with phenol concentration,and the photocatalytic degradation rate of phenol increases with Cr(VI) concentration.The photocatalytic reduction of Cr(VI) follows L-H kinetic equation,while the photocatalytic oxidation of phenol follows the first order kinetic equation.