Study On Co - Coagulation - Ultrafiltration Membrane Technology Of Ferromagnetism

The magnetic enhanced coagulation membrane filtration process as an effective water treatment technology was introduced into our research. Based on the conventional magnetic enhanced coagulation, zero valent iron(ZVI) as magnetic seeds was added to the process. In this study, by contrasting the characteristic indexes and fouling mitigation to analyze the differences of conventional coagulation membrane filtration, magnetic iron oxide(MIO) coagulation membrane and ZVI-coagulation membrane filtration process.Firstly, ZVI as magnetic seeds was added to magnetic enhanced coagulation membrane filtration process, thus the effect on flocs(size and fractal dimension(because of fractal dimension and floc size could influence the subsequent membrane fouling)) and water quality index were investigated. When the dosage of ZVI was 6-9mg/L, the results were better. Results indicated that membrane fouling can be mitigated by adding ZVI. By contrasting the characteristic indexes (TOC, CODMn, UV254) and membrane specific flux, the removal rates of these indexes in enhanced coagulation with ZVI were higher than those in conventional coagulation. Three dimensional fluorescence analysis demonstrated that the removal effect was better than without ZVI. Furthermore, it appeared that the added ZVI influenced the floc and cake layer properties, making floc larger and denser, cake layer looser and more permeable, respectively.Secondly, this study comparatively analyzed conventional coagulation membrane filtration and MIO-coagulation membrane filtration, results indicated that the addition of MIO can improve removal efficiency and mitigate membrane fouling to some extent, total resistance was relatively low. Besides, adding less dosage can achieve the same effect.Finally, by contrasting three process, the addition of ZVI had certain superiority in removal efficiency and fouling mitigation. The variation of ORP and ionic concentration indicated the activeness of ZVI. XRD and SEM analyses proved that ZVI reacted in the process and might adsorb some contaminants. Image of floc and SEM of cake layer also intuitively reflected differences of three processes.