Abstract:
Fouling comparisons of the organic fractions in surface and algae-laden waters make it possible to determine the main compounds responsible for the fouling of ultrafiltration (UF) membranes. This study examined the fouling of UF membranes and its relationship to the characteristics of the organic fractions found in drinking-water supply. Four types of water were prepared by combining natural organic matter (NOM) from lake water with algal organic matter (AOM) from four algae species commonly found in freshwater. Liquid chromatography-organic carbon detection (LC-OCD) and a fluorescence excitation-emission matrix (FEEM) were used to analyze the feed water and permeate to assess the interactions between and fouling behavior of the organic fractions. The results showed that the interaction of large-molecular-weight AOMs on the membrane surfaces and their transport through the membrane pores were the main fouling mechanisms. Polysaccharides followed by protein-like substances were the organic compounds responsible for the fouling of the UF membranes. The fouling affinity of these substances was attributed to two processes, the adsorption of their carboxyl, hydroxyl and cationic groups on the membrane surfaces, and the molecular complexation of their organic groups. The humic substances\' retention was marginal and attributed to the synergetic effects of the polysaccharides and proteins.
摘要:
对表面和充满藻类的水中的有机部分进行污垢比较,可以确定导致超滤(UF)膜结垢的主要化合物。这项研究检查了UF膜的结垢及其与饮用水供应中有机组分特征的关系。通过将湖水中的天然有机物(NOM)与淡水中常见的四种藻类的藻类有机物(AOM)相结合,制备了四种类型的水。使用液相色谱-有机碳检测(LC-OCD)和荧光激发-发射矩阵(FEEM)分析给水和渗透物,以评估有机馏分之间的相互作用和结垢行为。结果表明,大分子量AOM在膜表面的相互作用及其通过膜孔的传输是主要的污染机理。多糖和蛋白质样物质是造成UF膜污染的有机化合物。这些物质的污垢亲和力归因于两个过程,它们的羧基的吸附,膜表面上的羟基和阳离子基团,以及它们有机基团的分子络合。腐殖质的保留很少,归因于多糖和蛋白质的协同作用。