UV/TiO2体系中SF Blue染料溶液的降解动力学研究

Degradation Kinetics of Dye SF Blue in UV/TiO2 Suspension System

关键词:  印染废液  降解  TiO₂  光催化  活化能

Key words:  printing and dyeing waste water  degradation  titania  photocatalysis  activation energy

摘要:

以市售商品TiO₂为光催化剂,以SF Blue制衣染料溶液模拟实际印染废水,研究光照时间、TiO₂投加量、染料溶液浓度、pH值、温度对UV/TiO₂体系降解染料废液效果的影响和宏观动力学。结果表明,UV/TiO₂对SF Blue染料废液具有良好的处理效果,而且在发生光催化降解的同时还伴随着光分解反应,光催化降解反应为表观二级反应,活化能50.1kJ·mol^-1,指前因子4.47×10⁵L·mg^-1·min^-1;光分解反应为表观一级反应,活化能14.8kJ·mol^-1,指前因子1.67min^-1。UV/TiO₂体系降解染料废液受到光照时间、TiO₂投加量、染料溶液浓度、pH值、温度等因素的影响,TiO₂最佳投加量为1.2g·L^-1,染料溶液初始pH值 ≤ 3时,TiO₂对SF Blue染料具有强烈吸附作用。

Abstract:

The degradation efficiency, effect factors (such as reaction time, TiO₂ dosage, dye concentration, initial pH value and temperature) and kinetics of dye SF Blue in UV/TiO₂ suspension system are investigated. The results show that UV/TiO₂ has a high activity on degradation of dye SF Blue in solution, and the photodecomposition reaction of the dye is concurrent besides the photocatalytic degradation. The results also show that the photocatalytic degradation of the dye in UV/TiO₂ system is a second-order reaction apparently, with activation energy 50.1 kJ·mol^-1 and pre-exponential factor 4.47×10⁵ L·mg^-1·min^-1, while the photodecomposition of the dye in UV system is a first-order reaction apparently, with activation energy 14.8 kJ·mol^-1 and pre-exponential factor 1.67 min^-1. In addition, the adsorption of the dye on TiO₂ surface becomes very strong when the initial pH value of dye solution being and below 3.