光催化协同TiO_2动态膜去除水中腐植酸及膜污染特性

Characteristics of membrane pollution in process of Ti O2 dynamic membrane coupled with photocatalysis for removal of humic acid in wastewater

针对物理扰动模式控制动态膜污染使涂膜层脱落方面的局限性,提出光催化氧化技术协同动态膜降低膜污染,对比了陶瓷微滤膜、动态膜、光催化协同动态膜处理含腐植酸废水及含腐植酸/TiO2混合废水过程中的膜通量、污染物去除率及膜污染阻力分布的变化趋势。结果表明:光催化协同作用可有效提高动态膜过滤腐植酸溶液过程中的膜通量、总有机碳(TOC)及UV254的去除率,并同时降低可逆污染阻力及不可逆污染阻力,其中可逆污染阻力明显大于其他部分阻力,可逆污染是造成膜通量衰减的主要原因。光催化预处理时间越长,稳态膜通量、TOC及UV254去除率增幅越显著,控制膜污染越有效。光催化预处理2h和8h再动态膜过滤时TOC去除率分别可达到80%和90%以上,UV254去除率都可达95%以上。

In order to solve the problem of peeling of the coated layer using physical disturbance models to control the dynamic membrane pollution,this paper presented photocatalysis coupled with dynamic membrane for mitigation of membrane fouling,and compared membrane permeate fluxes, pollutants removal and membrane fouling resistance distributions in ceramic microfiltration membrane,dynamic membrane and dynamic membrane/photocatalysis hybrid system in treatment of wastewater containing humic acid or humic acid/TiO2. The results showed that the photocatalysis dynamic membrane effectively improved the steady permeate flux and removal rates of pollutants,and reduced the irreversible and reversible membrane fouling resistances. The reversible membrane fouling resistances and the main reason leading to the reduction of membrane permeate fluxes were obviously greater than the other parts of membrane resistances. With longer pretreatment by photocatalysis,the membrane permeate fluxes and removal rates of TOC and UV254 were improved more significantly, thus the membrane fouling was more efficiently controlled. After 2 and 8 hours of photocatalysis pretreatment following by dynamic membrane filtration,the TOC removal rates were greater than 80% and 90%,respectively,and the UV254 removal rates reached more than 95%.