School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China.
J Hazard Mater. 2010 May 15;177(1-3):814-21. doi: 10.1016/j.jhazmat.2009.12.106. Epub 2010 Jan 7.
Photocatalysis is a promising technology for treatment of gaseous waste; its disadvantages, however, include causing secondary pollution. Biofiltration has been known as an efficient technology for treatment volatile organic compounds (VOCs) at low cost of maintenance, and produces harmless by-products; its disadvantages, include large volume of bioreactor and slow adaptation to fluctuating concentrations in waste gas. A bench scale system integrated with a photocatalytic oxidation and a biofilter unit for the treatment of gases containing toluene was investigated. The integrated system can effectively oxidize toluene with high removal efficiency. The photocatalytic activity of N-TiO(2)/zeolite was evaluated by the decomposition of toluene in air under UV and visible light (VL) illumination. The N-TiO(2)/zeolite has more photocatalytic activity under complex light irradiation of UV and visible light for toluene removal than that of pure TiO(2)/zeolite under UV or visible light irradiation. N-TiO(2)/zeolite was characterized by scanning electron microscopy (SEM), X-ray photoelectron spectrum analysis (XPS), Fourier transform infrared spectroscopy (FT-IR), and as-obtained products were identified by means of gas chromatography/mass spectrometry (GC/MS). Results revealed that the photocatalyst was porous and was high photoactive for mineralizing toluene. The high activity can be attributed to the results of the synergetic effects of strong UV and visible light absorption, surface hydroxyl groups. The photocatalytic degradation reaction of toluene with the N-TiO(2)/zeolite follows Langmuir-Hinshelwood kinetics. Toluene biodegradation rate matches enzymatic oxidation kinetics model.
光催化是一种很有前途的气态废物处理技术；但它的缺点是会造成二次污染。生物过滤一直以来被认为是一种高效的挥发性有机化合物（VOC）处理技术，其维护成本低，且产生的副产物无害；缺点是生物反应器体积大，对废气浓度波动的适应能力慢。本研究采用光催化氧化与生物过滤集成的中试系统处理含甲苯废气。结果表明，该集成系统能有效地氧化甲苯，去除效率高。通过在 UV 和可见光照（VL）下空气中甲苯的分解来评价 N-TiO(2)/沸石的光催化活性。N-TiO(2)/沸石在 UV 和可见光的复合光照射下对甲苯的去除具有比纯 TiO(2)/沸石在 UV 或可见光照射下更高的光催化活性。采用扫描电子显微镜（SEM）、X 射线光电子能谱分析（XPS）、傅里叶变换红外光谱（FT-IR）对 N-TiO(2)/沸石进行了表征，通过气相色谱/质谱联用（GC/MS）对所得产物进行了鉴定。结果表明，该催化剂多孔，对甲苯的矿化具有很高的光活性。高活性归因于强 UV 和可见光吸收、表面羟基的协同作用。N-TiO(2)/沸石对甲苯的光催化降解反应遵循 Langmuir-Hinshelwood 动力学。甲苯的生物降解速率符合酶氧化动力学模型。
