文献类型：期刊文献

英文题名：The Role of Coagulants in Constructing an Effective Pre-Filtering Layer for Membrane Fouling Control

作者：Li, Yue[1]; Yu, Meifeng[1]; Meng, Xianghao[1]; Liang, Dawei[1]; Liu, Hongju[1]; Yang, Linyan[2]; Shen, Liang[3]; Zhao, Qian[4]; Meng, Shujuan[1]

机构：[1] School of Space and Environment, Beihang University, Beijing, 100191, China; [2] School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai, 200237, China; [3] Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China; [4] School of Municipal and Environmental Engineering, Shandong Jianzhu University, 1000 Fengming Road, Jinan, 250101, China

年份：2022

外文期刊名：SSRN

收录：EI(收录号：20220305190)

语种：英文

外文关键词：Coagulation - Membranes - Microfiltration - Sodium alginate

摘要：Organic matter is one of the major components causing membrane fouling in feedwater to membrane system, which contains humic acid, polysaccharide, protein and so on. Coagulants are often used to alleviate membrane fouling caused by organics. However, the effect mechanism of coagulant components on organic foulants are lack of in-depth analysis, especially the impact on the morphological characteristics of foulants at the micro level and the related fouling mitigation mechanism. In this study, sodium alginate is selected as the surrogate of organic foulants to study the influence mechanism of typical coagulants Al 3+ and Fe 3+ on fouling control. The results show that the addition of different concentrations of coagulants will deeply affect the process of polysaccharide aggregation to form transparent exopolymer particles (TEP), and the concentration and morphological characteristics of TEP are dependent on the level of coagulants. Given a certain level of alginate (50 mg/L), both Al 3+ and Fe 3+ show the highest production of TEP at the concentration of 0.05 mM and further increase of coagulants surprisingly reduce the TEP amount. Combination of filtration tests and analysis of fouling mechanism reveal that the small and amorphous TEP developed at low concentration of coagulant is intercepted by the membrane and forms a dense fouling layer resulting in the decreasing of membrane flux, while larger granular TEP developed from alginate accumulates on the membrane surface to form a porous fouling layer which in turn acts as a pre-filtering layer mitigating fouling. This study indicates that the addition of coagulants significantly changes the microscopic properties of foulants and the fouling mechanism. With the qualitative and quantitative analysis of TEP formed by foulant, the theoretical basis and data support are provided for the addition of coagulation to construct an effective pre-filtering layer for membrane fouling control. ? 2022, The Authors. All rights reserved.