太湖原水中膜污染物质的确定与表征

采用混凝沉淀和浸没式微滤膜联用技术处理太湖原水,考察组合工艺中的有机物亲疏水性和分子量分布变化,并分析化学清洗水的有机物组分,以期确定造成膜污染的主要物质成分.结果表明,混凝预处理可有效去除大分子的亲水性有机物,这类有机物仅能导致可逆污染,而中等和小分子的有机物会导致不可逆污染.此外,三维荧光光谱表明与膜污染关系最密切的2个区域为:λex=230nm/λem=330~350nm (区域Ⅰ)和λex=280nm/λem=300~350nm (区域Ⅳ),其对应的胞外蛋白质类有机物和溶解性微生物产物(SMP)是造成微滤膜不可逆污染的主要物质.

Identification and characterization of membrane fouling substances in Taihu Lake

This study employed coagulation-sedimentation-submerged microfiltration membrane process to treat raw water from Taihu Lake and investigated the variation of hydrophilicity/hydrophobicity and molecular weight (MW) of organic matter along this treatment process. The organic component of chemical cleaning water was also analyzed to confirm the main material composition causing the membrane fouling. Coagulation pretreatment could effectively remove organics with hydrophilic macromolecules responsible only for reversible fouling, but showed less effective in removing the mid- and low-MW organic matters responsible for irreversible fouling. In addition, three dimensional excitation-emission matrix (3DEEM) fluorescence spectra exhibited that the two regions closely related to membrane fouling were: λex=230nm/λem=330~350nm (RegionⅠ) and λex=280nm/λem=300~350nm (Region Ⅳ). The corresponding organic foulants in the two regions were extracellular protein-like organics and soluble microbial products (SMP), which were responsible for irreversible fouling.