壳聚糖/无纺布复合膜的制备及其耐污染性能研究

Preparation of CS/NWF Composite Membrane and Research of its Antifouling Performance

采用内表面涂覆法,制备天然高分子壳聚糖与聚丙烯无纺布的复合膜。环境扫描电子显微镜观察发现,壳聚糖/无纺布复合膜的形态结构变化较小。衰减全反射-傅立叶变换红外光谱分析表明膜表面引入了-OH和-NH2。复合膜表面的亲水性明显提高,水动态接触角从基膜的95°降至改性后的33.4°。通过考察膜的清水通量和阻力及MBR运行出水的粒径分布,分析基膜及复合膜的渗透和截留性能,表明复合膜的渗透能力和截留能力比基膜均有提高。对复合膜的抗污染性能进行了分析,结果表明复合膜表面BSA的静态吸附量降低了96.5%,在MBR中持续运行60小时后,纯水通量降低率比无纺布基膜低24.66%,通量在水洗和化学清洗后的恢复率比基膜分别高38.76%和35.78%,而污染后的比通量是基膜的1.85倍。表明无纺布膜在经过壳聚糖改性后,抗污染能力明显增强。

The chitosan/polypropylene non-woven fabric （CS/NWF） composite membrane was prepared by internal surface coating method. The photographs of environmental scanning electron microscope （ESME） show that the morphologies of the prepared composite membrane changes slightly,and the spectra of Fourier transform infrared-attenuated total reflectance show that the functional groups of -OH and -NH2 are introduced on the membrane surface. The hydrophilicity of the composite membrane is improved,and the water contact angle of the membrane surface decreases from 95.08° to 33.40°. Pure water flux,membrane resistance and the particle size distribution in the effluent of the membrane bioreactor （MBR） show that the permeation and retention properties of the composite membrane are improved. The antifouling property of the prepared composite membrane was investigated. Compared with the original NWF membrane,the static absorption quantity of BSA decreases by 96.50%,and after continuous operation in the MBR for about 60 h,the reduction of pure water flux of the composite membrane with 90.5%（wt） CS is 24.66% lower,the flux recoveries after water and chemical cleaning are 38.76% and 35.78% higher,respectively,than those of the original NWF membrane. Moreover,using the prepared composite membrane,the flux ratio after fouling is 1.85 times bigger than that of original NWF membrane,it implies that the antifouling property of the NWF was improved by internal surface coating CS.