中文摘要：

在不同Mg2+条件下,使用耗散型石英晶体微天平(QCM-D)技术考察了腐植酸(HA)在乙烯-乙烯醇共聚物(EVOH)膜面的吸附行为及HA吸附层结构特征,定量测定了EVOH-HA及HA-HA之间作用力随Mg2+含量的变化特征,结合宏观EVOH膜污染实验,揭示Mg2+对天然有机物超滤膜污染行为的影响机制.结果表明:Mg2+对HA污染行为的影响分为2个阶段:在较低的Mg2+条件下,电荷屏蔽、络合及架桥等作用使得EVOH及HA表面所带净电荷量减小,削弱了EVOH-HA及HA-HA之间的静电排斥力,进而促进HA在膜面的吸附累积,且形成密实的HA污染层,相应膜污染加剧.随着Mg2+含量继续增大,EVOH-HA及HA-HA之间水合排斥力逐渐增强,成为控制膜污染的主要因素,有效减缓了HA在EVOH膜面的吸附累积速率,且膜面形成松散多孔的HA吸附层,伴随着膜污染速率及污染幅度的减小.

英文摘要：

In this study,adsorption behaviour of humic acid(HA)on Ethylene-vinyl alcohol copolymer(EVOH)ultrafiltration membrane surface and HA adsorbed layer structure were determined in the different concentration of Mg2+,combined with the interaction forces of EVOH-HA and HA-HA,and HA fouling experiments to unravel the influence mechanism of Mg2+on natural organic matter fouling of ultrafiltration membrane.According to the results,the effects of Mg2+on HA fouling were in two stages:at the lower Mg2+range,the net charges of EVOH and HA surface were reduced because of the charge screening and complex bridge and this weaken the electrostatic repulsion of EVOH-HA and HA-HA,thus a higher deposition rate of HA was accumulated and a denser HA layer was formed on the membrane surface,so the membrane fouling aggravated.However,when Mg2+dosage above a critical value,the hydration repultion forces were provoked effectivity,which caused a decrease in the deposition rate and extent of HA onto the membrane surface,and more nonrigid HA layer was formed,corresponding membrane fouling was mitigated.