作　　者： ; ; ; ; ;

机构地区： 华南师范大学化学与环境学院

出　　处： 《华南师范大学学报（自然科学版）》 2006年第4期93-99,共7页

摘　　要： 比较了光催化法、电解氧化法和光电催化法对模型污染物———曙红的降解效果,对光电催化法降解曙红进行了重点研究,考查了pH、电流密度和曙红浓度对降解效果的影响,并对在不同pH下光电催化降解曙红的动力学进行了研究.研究结果表明:光电催化法对曙红的降解率高于电解氧化法和光催化法,电解和光催化之间存在着协同效应;光电催化法对曙红的降解率随pH的升高而下降;在较低的电流密度范围内(低于10.0 mA/cm2)增大电流密度可明显增强曙红降解效果,而过大的电流密度则没有明显的促进作用;曙红降解率随曙红初始浓度的增加而降低,而降解浓度则随曙红初始浓度的增加而增加.在反应的初始阶段曙红的降解符合一级动力学方程,溶液在pH为4.0、7.0、11.0时,速率常数分别为k=8.335×10-2m in-1、1.69×10-2m in-1、1.0×10-2m in-1. Degradation of eosin by photocatalysis, electrolysis and electrolysis - photocatalysis was studied in this paper. Effect of initial pH, current density and initial eosin concentration on degradation of eosin in electrolysis - photocatalysis system, and the kinetics of degradation process at different pH were investigated. The degradation and COD removal of eosin in electrolysis-photocatalysis system was founded to be much more efficient than the sum of those by sole electrolysis and photocatalysis alone, indicating a significant synergetic effect betw ue exerted een electrolysis and photocatalysis. In electrolysis - photocatalysis system pH valgreat impact on the degradation of eosin. Degradation fraction of eosin decreased with the rise of pH value. Increasing current density from 5.0 mA/cm^2 to 10.0mA/cm^2 resuhed in a pronounced increase in degradation ratio, but a further increase in current had little influence on eosin removal. With the increase of initial concentration of eosin, the degradation ratio dropped but the concentration of degraded eosin rised. It was also founded that the decomposition of eosin at initial stage of the degradation process at pH = 4.0, 7.0,11.0 in electrolysis -photocatalysis system was well fitted by the first order kinetics, andthe first order reaction rate constant was 8. 335 ×10^-2min^-1, 1.690 ×10^-2min^-1 and 1. 000 ×10^-2min^-1 respectively.

关 键 词： 光电催化 协同 降解 曙红

领　　域： [环境科学与工程]