磁场强化絮凝减缓膜污染的影响因素分析

Analysis of the influence factors of magnetic enhanced flocculation mitigating membrane fouling

研究磁场及磁致效应对磁强化絮凝膜过滤工艺(Magnetic enhanced flocculation membrane filtration,MEFMF)处理地表水中膜污染的影响;运用Design-Expert7.0软件进行试验设计,考察了磁化时间、混凝剂浓度和磁粉浓度对磁强化絮凝膜过滤工艺中膜污染变化的影响,结果表明磁化时间、混凝剂浓度以及两者的协同作用是影响磁强化絮凝膜过滤工艺中膜污染的主要因素.磁化时间和混凝剂浓度的协同作用影响着磁絮体的粒径和膜表面滤饼层形态,磁絮凝工艺形成的絮体粒径大且分型维数高,减弱了膜孔堵塞,减缓了膜污染.磁强化絮凝减缓膜污染最佳试验条件是磁化时间为6 min,Fe3O4浓度为8 mg·L-1,FeCl3浓度为44 mg·L-1.

In this study, a magnetic enhanced flocculation membrane filtration （MEFMF） process was developed to treat surface water. The influence of magnetic field and magnetic effectiveness on membrane fouling was investigated. The experiments were designed using the Design-Expert7.0 software in the aspect of the influence of magnetization time, coagulant concentration and Fe3 04 concentration on the MEFMF. The results showed that the main influence factor of MEFMF were magnetization time, coagulant dose and their synergistic effect. The flocs and cake layer of the membrane surface were affected by the synergistic effect of magnetization time and coagulant dose. Flocs forming in MEFMF are of larger fractal dimension and particle size, and result in weakened membrane pore blocking and mitigation of the membrane fouling. The optimized experimental conditions for MEFMF to mitigate membrane fouling were magnetization time of 6 rain, Fe3 04 concentration of 8 mg·L^-1, and FeC13 concentration of 44 mg·L^-1.