Ma Ying-Shih, Chang Cheng-Nan, Chiang Yen-Pei, Sung Hsiao-Fan, Chao Allen C
Department of Environmental Engineering and Health, Yuanpei University of Science and Technology, Hsinchu 300, Taiwan, ROC.
Chemosphere. 2008 Mar;71(5):998-1004. doi: 10.1016/j.chemosphere.2007.10.061. Epub 2008 Feb 21.
Photocatalytic degradation of lignin was studied with the use of catalysts TiO(2) and Pt/TiO(2). The influence of several experimental parameters, i.e. pH, catalyst dosage and illumination on lignin degradation was investigated. The results showed that application of UV irradiation alone has almost no effect on the reduction of dissolved organic carbon (DOC) and American Dye Manufacture Institute value (ADMI). However, the addition of TiO(2) and Pt/TiO(2) reduced the original DOC (251 mg l(-1)) by more than 40% within 30 min of treatment and the reaction can be simulated with pseudo-first order kinetics. Rapid degradation of lignin was observed in acidic solution using either TiO(2) or Pt/TiO(2) as the catalyst compared to high pH cases. The content of Pt in the Pt/TiO(2) catalyst is 1%. In addition, too much catalyst addition has not increased the DOC and ADMI reduction proportionally. The investigation also indicated that the photocatalytic degradation rates could be enhanced 1-6 times faster after doping TiO(2) with Pt in different pH cases. A modified Nernst type model was adopted to simulate the decoloring process using TiO(2) and Pt/TiO(2) based on the profiles of oxidation reduction potential during the photocatalytic reaction. The developed equation can be used to predict the color removal efficiency of lignin wastewater by the photocatalytic process.
利用催化剂TiO₂和Pt/TiO₂研究了木质素的光催化降解。研究了几个实验参数，即pH值、催化剂用量和光照对木质素降解的影响。结果表明，单独使用紫外线照射对溶解有机碳（DOC）和美国染料制造商协会值（ADMI）的降低几乎没有影响。然而，添加TiO₂和Pt/TiO₂在处理30分钟内使原始DOC（251 mg l⁻¹）降低了40%以上，并且该反应可用准一级动力学进行模拟。与高pH值情况相比，在酸性溶液中使用TiO₂或Pt/TiO₂作为催化剂时观察到木质素的快速降解。Pt/TiO₂催化剂中Pt的含量为1%。此外，过多添加催化剂并没有按比例增加DOC和ADMI的降低率。研究还表明，在不同pH值情况下，用Pt掺杂TiO₂后，光催化降解速率可提高1至6倍。基于光催化反应过程中的氧化还原电位曲线，采用改进的能斯特型模型来模拟使用TiO₂和Pt/TiO₂的脱色过程。所建立的方程可用于预测光催化过程中木质素废水的脱色效率。
