Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore 119260, Singapore.
Chemosphere. 2010 Mar;79(2):205-9. doi: 10.1016/j.chemosphere.2010.01.042. Epub 2010 Feb 19.
The photocatalytic oxidation of nonionic surfactant, Brij 35 in aqueous TiO2 suspensions was investigated as a function of catalysts loading, light intensity (I), initial Brij 35 concentration Brij, dissolved oxygen concentration [p(O2)], and pH. A monolithic swirl-flow photoreactor was used that allowed to perform a systematic analysis of rates at various loadings of TiO22 in order to distinguish "kinetic" and "transport" limited regimes for the photocatalytic degradation of Brij 35 in TiO2 suspensions. The optimal catalyst loading was determined to be 0.1 g L(-1) TiO2 at a neutral pH. The true kinetic dependences of the photocatalytic degradation on I and Brij were determined. A small increase in oxidation rate was observed with an increase in the partial pressure of the oxygen [p(O2)] in the system. The rates as a function of Brij and [p(O2)] were interpreted using a Langmuir-Hinshelwood model. The complete photocatalytic degradation of Brij 35 was obtained in acidic to basic pH range, however, the removal of Brij 35 removal and subsequent decrease in TOC levels were more efficient at a neutral pH than acidic or basic pH.
研究了非离子表面活性剂 Brij 35 在 TiO2 悬浮液中的光催化氧化作用，考察了催化剂负载量、光强（I）、初始 Brij 35 浓度Brij、溶解氧浓度[p(O2)]和 pH 的影响。采用整体旋流光反应器，能够在不同 TiO22 负载量下进行速率的系统分析，以区分 TiO2 悬浮液中 Brij 35 光催化降解的“动力学”和“传质”限制区。在中性 pH 下，确定最佳催化剂负载量为 0.1 g L(-1) TiO2。确定了光催化降解对 I 和Brij的真实动力学依赖性。观察到随着体系中氧分压[p(O2)]的增加，氧化速率略有增加。使用 Langmuir-Hinshelwood 模型解释了Brij和[p(O2)]与速率的关系。在酸性到碱性 pH 范围内可实现 Brij 35 的完全光催化降解，但在中性 pH 下，Brij 35 的去除和随后 TOC 水平的降低比在酸性或碱性 pH 下更有效。
