Wang Chuan, Zhang Xianghua, Liu Hong, Li Xiangzhong, Li Wenzhao, Xu Hengyong
School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, China.
J Hazard Mater. 2009 Apr 30;163(2-3):1101-6. doi: 10.1016/j.jhazmat.2008.07.064. Epub 2008 Jul 23.
The photocatalytic (PC) degradation kinetics of sulfosalicylic acid (SSA) at different pH using TiO2 microspheres were elucidated by modeling. The resultant model had special consideration of adsorption and pH. The adsorption isotherms showed that the LC/MS(2)-identified intermediates were weakly adsorbed on the TiO2 microspheres, thus their adsorption was neglected in the modeling. By contrast, the SSA was significantly adsorbed, thus its adsorption retained as an item in the model. Consequently, a non-first-order model was obtained. Through the modeling, it was elucidated that the reaction rate increased non-linearly with the SSA adsorption equilibrium constant. Meanwhile, it was elucidated that a pH increase favored the hydroxyl radical production to accelerate the SSA degradation, while impeded the SSA adsorption to slower it, hence a neutral pH caused the fastest SSA degradation.
通过建模阐明了使用二氧化钛微球在不同pH值下磺基水杨酸（SSA）的光催化（PC）降解动力学。所得模型特别考虑了吸附和pH值。吸附等温线表明，液相色谱/质谱联用（LC/MS(2)）鉴定出的中间体在二氧化钛微球上吸附较弱，因此在建模中忽略了它们的吸附。相比之下，SSA被显著吸附，因此其吸附作为一项保留在模型中。结果得到了一个非一级模型。通过建模表明，反应速率随SSA吸附平衡常数呈非线性增加。同时表明，pH值升高有利于羟基自由基的产生，从而加速SSA降解，但会阻碍SSA吸附，使其降解变慢，因此中性pH值导致SSA降解最快。
