Kinetic study and modeling on photocatalytic degradation of para-chlorobenzoate at different light intensities

被引:63
作者
Meng, YB [1 ]
Huang, X [1 ]
Wu, YX [1 ]
Wang, XM [1 ]
Qian, Y [1 ]
机构
[1] Tsing Hua Univ, Dept Environm Sci & Engn, Environm Simulat & Pollut Control State Key Joint, Beijing 100084, Peoples R China
关键词
kinetics; light intensity; model; para-chlorobenzoate; photocatalysis;
D O I
10.1016/S0269-7491(01)00184-1
中图分类号
X [环境科学、安全科学];
学科分类号
08 ; 0830 ;
摘要
In order to clarify the dependence of apparent adsorption constant K, in the Langmuir-Hinshelwood (L-H) model on the incident light intensity, photocatalytic degradation kinetic characteristics were experimentally investigated at different light intensities using para-chlorobenzoate (4-CBA) as a model compound. In all cases 4-CBA initial degradation rates showed dependence on 4-CBA initial concentration, which can be described by the L-H model. However, the adsorption constant K-s and rate constant k(r) obviously varied with light intensity. To account for the experimental finding, slight modification of the classic kinetic model developed by Turchi and Ollis was tentatively proposed by assuming insufficiency of H2O/OH- available for photo-activated holes' scavenging. Such a kinetic model predicts that both k(r) and K-s(-1) are linearly proportional to the square root of the intensity in a rather large intensity range. The validity of the modified model was proved by fitting it to the experimental data. (C) 2002 Elsevier Science Ltd. All rights reserved.
引用
收藏
页码:307 / 313
页数:7
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