纳米TiO_2光催化降解制浆废水动力学研究

Photocatalyst Degradation Kinetics of Wastewater from Papermaking on Nanometer Size Titanium Dioxide

以四异丙醇钛和异丙醇等为原料,采用溶胶□凝胶(Sol-Gel)法制备纳米TiO2光催化剂,研究了纳米TiO2对造纸废水的暗吸附规律和光降解性能.讨论了不同实验条件如催化剂用量、光照时间及废水pH值等因素对制浆造纸废水COD去除率的影响.结果表明:纳米TiO2对造纸废水的吸附规律都较好地符合Langmuir和Freundlich吸附等温模型;光催化降解反应遵循Langmuir-Hinshelwood动力学模型.焙烧温度为400℃,焙烧时间2h制备的纳米TiO2用量5g/L,pH=2,160W高压汞灯光照反应2h,造纸废水COD的去除率可达91.83%.

The photocatalyst of nano-TiO2 was prepared by sol-gel method.The influences of amount of catalyst,radiation time and pH value on the photocatalytic degradation of papermaking wastewater on nano-TiO2 were studied.The adsorption and photocatalytic oxidation proceses of wastewater from papermaking on nano-TiO2 were studied.The results indicate that the adsorption law of wastewater from papermaking on nano-TiO2 fit in well with the Langmuir model and Freundlich model.The optimal experimental conditions were obtained： calcination temperature 400℃,calcination time 2.0 h,amount of catalyst 5g/L,pH value of papermaking wastewater 2.0,and radiation time 2.0 h,the COD removal rate of papermaking wastewater reached 91.83%.The photodegradation fits in with Langmuir-Hinshelwood kinetic mode.