季铵盐两性离子陶瓷膜制备及抗污染性能研究

Research on the preparation and the antifouling performance of quaternary ammonium zwitterion ceramic composite membrane

以3-氨丙基三甲基硅烷(KH551)与3-缩水甘油基氧基丙基三甲氧基硅烷(KH560)为基体,合成含叔胺基硅氧烷溶胶后涂覆于陶瓷膜表面,并在2-溴乙基磺酸钠(SBTS)作用下生成季铵盐,制备出季铵盐两性离子复合陶瓷膜.表征结果证明,季铵盐成功地接枝于膜表面,优化后改性膜接触角约为39.4°,且通量受凝胶负载影响程度小.微生物吸附实验表明,改性后膜相比改性前减少了90.5%的活菌吸附,动态过滤通量至少提高8.2%.以污泥中溶解性微生物产物(SMP)、松散结合的胞外聚合物(LB-EPS)作为有机污染物模型,将改性前后膜通过SMP、LB-EPS溶液,考察通量变化,并通过Hermia模型分析污染机理,激光共聚焦显微镜(CLSM)观察污染物黏附于膜表面情况.结果表明,过滤SMP、LB-EPS至稳定时,膜改性后比通量比改性前分别提高38.9%、29.3%,反洗后通量提高了11.6%、32.3%,且改性膜表面污染物残留量分别减少27.2%、41.5%.以上结果均表明,通过季铵盐两性离子进行表面修饰能有效提高陶瓷膜抗污染性能.

Using 3-Aminopropyltrimethoxysilane(KH551), 3-Glycidyloxypropyltrimethoxysilanen(KH560) as substrates, the siloxane sol containing tertiary amino was synthesized and coated on the ceramic membrane. The quaternary ammonium salt-zwitterion composite ceramic membrane was prepared by reacting with sodium 2-bromoethyl sulfonate(SBTS) for retarding the fouling in the MBR system. The surface properties, permeability, biofouling and organic fouling resistance of the modified membrane were characterized. The results showed that the quaternary ammonium salt was successfully grafted onto the surface of the membrane. After optimization, the contact angle of the modified membrane was about 39.4°, and the flux was almost unaffected by gelation. The results of static adsorption experiment showed that the adsorption of live bacteria decreased by 90.5% after modified, and the flux increased by at least 8.2%. Taking soluble microbial products(SMP) and loosely bound extracellular polymeric substances(LB-EPS) in sludge as organic fouling models, the flux changes of the membrane were characterized through SMP and LB-EPS solutions, the fouling mechanism was analyzed by Hermia model, and the adhesion of fouling to the membrane surface was observed by CLSM. The results showed when SMP and LB-EPS were filtered to stable flux, the specific flux of modified membrane was 38.9% and 29.3% higher than primary membrane, the flux after backwashing was increased by 11.6% and 32.3%, and the attached fouling on the surface of modified membrane were reduced by 27.2% and 41.5% respectively. The above results indicate the surface modification by quaternary ammonium salt-zwitterion can effectively improve the antifouling performance of ceramic membrane.