TiO_2覆膜沸石光催化剂制备及其降解造纸废水

Preparation and Photocatalytic Performance of TiO_2-coated Natural Zeolite in Degradation of Papermaking Wastewater

以钛酸四丁酯和乙醇为原料,采用溶胶-凝胶(Sol-Gel)法制备以天然沸石为载体的负载型TiO2光催化剂,并利用X射线衍射(XRD)和扫描电镜(SEM)等对其进行结构表征.通过自行设计的光催化反应器考察了溶胶-凝胶体系的组成、焙烧温度及焙烧时间、废水pH值、光催化剂用量和光反应时间等因素对光催化剂降解造纸废水性能的影响,同时讨论了该催化剂的可重复利用性,确定了天然沸石负载型TiO2的制备及处理造纸废水的最佳实验条件:无水乙醇/钛酸四丁酯体积比4.0,冰醋酸/钛酸四丁酯体积比0.1,水/钛酸四丁酯体积比0.15,硝酸/钛酸四丁酯体积比0.1,焙烧温度300℃、焙烧时间4.0h,造纸废水pH4.0,光催化剂用量50g/L,光照时间8.0h,在此条件下造纸废水COD去除率可达81.93%.

Using Ti（OC4H9）4 and C2HsOH as reaction raw materials, the photocatalyst of TiO2-coated natural zeolite was prepared by sol-gel method. The experimental techniques of XRD and SEM were used to characterize the prepared TiO2-coated photocatalyst. The influences of components of sol-gel system, calcination temperature and time, amount of catalyst, radiation time and pH value on the photocatalytic degradation of papermaking wastewater on the TiO2 coated natural zeolite were studied. The optimal experimental conditions were obtained： the volume ratios of C2HsOH to TiO（CaH9）4 4.0, CH3COOH to TiO（CaH9）4 0.1, H2O to TiO（CaH9）4 0.15 and HNO3 tO TiO（CaH9）4 0. 1, calcination temperature 300 ℃, calcination time 4.0 h, amount of catalyst 50 g/L, pH value of papermaking wastewater 4.0, and radiation time 8.0 h, the COD removal rate of papermaking wastewater reached 81.93% under the conditions. The experimental results show that TiO2-coated natural zeolite has a good photocatalytic activity to degrade papermaking wastewater.