Controlling Uf Membrane Fouling Caused By Algal Extracellular Organics Using Manganese Dioxide Adsorption

Ultrafiltration technology in drinking water treatment has wide prospects.However, it will produce serious membrane fouling when it is applied toeutrophic water which has a large quantity of algal, algal extracellular organicmatter (EOM) is a membrane pollution substances, so, alleviate membranefouling caused by EOM is worth further study. In this paper, we chooseMicrocystis aeruginosa as representative algae of the natural water, usingthree different manganese dioxide (including in situ manganese dio xide,precast manganese dioxide and commercial manganese dioxide) as adsorptionpretreatment methods, and studied the effect of manganese dioxide onultrafiltration membrane fouling caused by algal extracellular organic matter.Three kinds of manganese dioxide’s physicochemical properties andadsorption performance are different between each other, the results show that:the iodine adsorption value of in situ manganese dioxide are1.4times and2.2times than the value of prefabricated and commodity manganese dioxide, andthe methylene blue adsorption values were10times and100times as much asthe other two; and in situ formation manganese dioxide have abundant surfacehydroxyl, and has excellent adsorption performance of protein and humic acid,the removal rate of them was above90%.Then I studied the adsorption efficiency of three kinds of manganesedioxide on algal extracellular organic matter EOM, and found that in situmanganese dioxide, precast manganese dioxide and commercial manganesedioxidein’s best adsorbent dosage are respectively17.4mg/L,17.4mg/L and5mg/L. their’s best adsorption time, the oscillation frequency and solution pHon adsorption experiment were12h, pH=7.0and100r/min,, and three kindsof manganese dioxide mainly adsorpte large molecular algae in EOM proteinmaitirail.Studies on the ultrafiltration experiments show that: three kinds ofmanganese dioxide(whether filtered after adsorption or unfiltered afteradsorption), adsorption by in situ manganese dioxide can make the flu xdecline during the ultrafiltration reduced by10%than EOM alone, however,prefabricated and commodity has no obvious effect on the flux decline; in situmanganese dioxide is better than the other two in reducing irreversiblemembrane fouling,if unfiltered after in situ manganese dioxide adsorption manganese dioxide can reduce the irreversible pollution in ultrafiltrationexperiments from23%when EOM alone to8%, and if filtered, it can reducethe irreversible pollution from23%when EOM alone to17%.the se resultsshow that the formation of cake layer can reduce the irreversibility ofmembrane fouling.This paper completed the research of part characteristics of UFmembrane fouling, in the meantime, I carried out the parameters optimizationdesign about the adsorption pretreatment and the effects of pretreatment onUF membrane fouling, the research results of this paper can provide technicalsupports for the ultrafiltration’s application on the water treatment.