喷涂法负载TiO_(2)/MnO_(2)陶瓷膜催化臭氧氧化降解染料废水

Efficient degradation of dye wastewater by catalytic ozone reactive ceramic membrane of TiO_(2)/MnO_(2) by a facile spraying method

染料废水存在排放量大、色度高、COD大、可生化性差、难降解等特点,其处理存在低效高耗的问题.本研究首先通过水热法制备了TiO_(2)/MnO_(2)催化剂,对催化剂进行了XRD、XPS、SEM/EDS表征,以罗丹明B(RhB)溶液为模拟染料废水,进行了催化臭氧氧化降解RhB的性能对比研究.再通过喷涂成膜技术将TiO_(2)/MnO_(2)催化剂负载于平板式陶瓷膜表面,研制成反应性陶瓷膜(TiO_(2)/MnO_(2)-CM),自制了配套膜反应器,研究了TiO_(2)/MnO_(2)-CM水处理系统对RhB降解去除效果和水通量变化规律.结果表明,本工作成功合成了棒状和不规整球状结合的TiO_(2)/MnO_(2)催化剂,XPS结果表明存在Mn^(4+)活性中心,促进了催化臭氧活化能力.喷涂TiO_(2)/MnO_(2)催化剂后,陶瓷膜的纯水通量略有下降,12层为适宜的喷涂层数,采用TiO_(2)/MnO_(2)-CM对2 L初始浓度为20 mg·L^(−1)的RhB在臭氧浓度为2.5 g·m^(−3)条件下,反应40 min去除率可达100%,去除效率远高于空白膜,陶瓷膜负载TiO_(2)/MnO_(2)有助于提高O_(3)溶解性、加速生成·OH.本工作可为染料废水等难降解有机废水的高效低耗处理,提供新技术思路.

Dye wastewater exhibits characteristics of large production,high color,high COD,low biodegradability,and refractory.In this work,TiO_(2)/MnO_(2) hybrid catalyst was prepared by a hydrothermal method,and was characterized by XRD,XPS,and SEM/EDS.Its catalytic ozonation performance was evaluated to degrade a simulated dye wastewater of Rhodamine B(RhB).Afterwards,the TiO_(2)/MnO_(2) catalyst was loaded onto a planar ceramic membrane(CM)by a facile spraying method to prepare a reactive ceramic membrane(TiO_(2)/MnO_(2)-CM).Besides,a new TiO_(2)/MnO_(2)-CM fixed bed water treatment system was proposed,and its degradation performnce of RhB and permeate flux was comprehensively investigated.The results showed that rod-shaped and irregular spherical combined TiO_(2)/MnO_(2) catalysts were successfully synthesized,and the XPS results showed that the existence of Mn^(4+)provided active centers for the O_(3) reaction and promoted the ozone activation ability.In addition,the TiO_(2)/MnO_(2)-CM with twelve spraying layers revealed better degradation performance of the dye solution.As for 2 L of RhB with an initial concentration of 20 mg·L^(−1),under the condition of ozone concentration of 2.5 g·m^(−3),a reaction time of 40 min,the removal efficiency of RhB by TiO_(2)/MnO_(2)-CM could reach 100%.Besides,the up-mentioned removal rate is much higher than that of blank CM,which was mainly attributed to a increase of ozone solubility in water and promoting the production of·OH.This work could provide an alternative solution for the treatment of refractory organic wastewater with lower energy comsuption but higher efficiency.