膜传质强化催化臭氧氧化技术的研究与机理分析

Research and mechanism analysis on membrane mass transfer enhanced catalytic ozonation technology

为解决传统臭氧(O_(3))曝气技术O_(3)逸散及污染物处理效率不高等问题,以疏水性聚四氟乙烯(PTFE)中空纤维膜材料制成膜接触器,并进行膜接触O_(3)无气泡传质催化O_(3)氧化技术研究。以苯酚为污染物,通过对比实验、催化O_(3)氧化实验、动力学分析、自由基屏蔽实验、紫外-可见吸收光谱分析等对新技术的传质特性、氧化效果和氧化机理进行了研究。结果表明,相较于单独O_(3)氧化,催化氧化体系对苯酚的去除情况均存在不同程度的提升,其中α-Fe_(2)O_(3)表现出较高的O_(3)催化活性。屏蔽实验通过投加叔丁醇(TBA)和Na_(3)PO_(4)来屏蔽自由基和反应位点,COD去除率较正常实验时分别降低了21.05%和11.80%,说明催化剂表面的路易斯酸性位点是催生·OH的主要原因。膜接触O_(3)无气泡传质与α-Fe_(2)O_(3)催化O_(3)氧化具有良好的协同作用,高效去除苯酚的同时解决了O_(3)逸散问题。

In order to solve the O_(3)escaping and low pollutant treatment efficiency problems of traditional ozone(O_(3))aeration technology,a membrane contactor is made of hydrophobic polytetrafluoroethylene(PTFE)hollow fiber membrane material,and the study is performed on membrane contact O_(3)bubble-free mass transfer catalytic O_(3)oxidation technology.The mass transfer characteristics,oxidation effect and oxidation mechanism of the new technology are studied through contrast experiment,catalytic O_(3)oxidation experiment,kinetic analysis,free radical shielding experiment and UV-visible absorption spectrum analysis.Results show that compared with O_(3)oxidation alone,catalytic oxidation system delivers an improved removal of phenol to varying degrees,andα-Fe_(2)O_(3)shows higher O_(3)catalytic activity.In the shielding experiment,tert-butanol(TBA)and Na_(3)PO_(4) are added to shield free radicals and reaction sites.As a result,COD removal rates are 21.05%and 11.80%,respectively lower than by normal experiment,indicating that Lewis acid sites on the catalyst surface are the main reason for the generation of·OH.There is good synergistic effect between membrane contact O_(3)bubble-free mass transfer andα-Fe_(2)O_(3)catalytic O_(3)oxidation,which can efficiently remove phenol and solve the problem of O_(3)escaping.