纳米TiO_2薄膜光催化处理造纸废水的研究

STUDY ON THE PHOTO CATALYTIC ACTIVITY OF THE ANATASE TiO_2 FILMS IN DECOMPOSING PAPERMAKING WASTEWATER

采用溶胶-凝胶法在玻璃表面制备出锐钛矿结构的二氧化钛薄膜,通过X射线衍射(XRD)、扫描电子显微镜(SEM)和紫外-可见吸收光谱(UV-vis)等分析技术对其结构、显微结构和光学性能进行了表征;在波长为253nm的紫外灯照射下,对TiO2薄膜光催化降解造纸废水中的COD指数作了研究,探讨了初始浓度、pH值、光照时间对降解效果的影响.结果表明:当废水初始COD指数在900～2 700mg/L之间,pH为3.5,25℃紫外灯照射2.5h时,COD去除率高达89.5%.

The anatase TiO2 films were prepared on glass substrates through sol-gel method.The phase,morphology and optical property of as-prepared samples were characterized by X-ray diffraction,scanning electron microscopy and UV-vis absorption spectra analyses;the photo catalytic activity in decomposing papermaking wastewater under the radiation of ultraviolet lamp were also investigated by measuring COD of the wastewater before and after treatment;and the-effects of initial concentrations of wastewater,pH values and radiation time on the decomposing were systematically studied.The results indicate that COD of wastewater can be reduced by 89.5% with a concentration of wastewater between 900 mg/L and 2 700 mg/L,pH of 3.5,and radiation time of 2.5 h at 25 ℃.