膜生物反应器中膜污染层胞外多糖性质及污染特征

Characteristics of Extracellular Polysaccharide in Bio-fouling Layer of MBR

胞外多糖是污水处理膜生物反应器中的重要膜污染物质,经醇析、Sevag法去除蛋白质、层析纯化、透析、冷冻干燥得胞外多糖样品。紫外光谱扫描鉴定该胞外多糖样品不含核酸及蛋白质,分别采用HPLC、GC、FT-IR及SEM等手段对其性质进行分析,考察其对聚偏氟乙烯膜的污染特征。结果表明,所得胞外多糖的重均分子量Mw为4.8×106,糖苷键类型主要为1-3和1-6型,是由葡萄糖、鼠李糖、木糖、甘露糖等组成、具有高度分枝网状结构的杂多糖。胞外多糖膜污染过程受沉积层控制,膜的主要污染形式为胞外多糖在膜表面的沉积。

Analysis of extracellular polysaccharide (EPS) from the fouling layer of a MBR which consists of PVDF hollow fiber modules was made by using instruments such as HPLC, GC, FT-IR and SEM. Result shows EPS's molecular weight, main components and chemical structure. It is concluded that filtration resistance which leads to flux drops attributes to EPS deposition onto the membrane surface.