The Research Of Modification And Pollution Of The Polypropylene Membrane

MBR is a water treatment technology that has been widely used in recent years. MBRhas small space occupation and high efficiency of the reaction by all the praise. However, thepollution is always the most important factor that has a big effect on treatment efficiency ofMBR. There are many influential factors of membrane fouling, such as membrane material,the nature of the sludge mixture, operation conditions and so on. This article mainly studiedmodification of membrane materials, that is, by use membrane surface modification toimprove membrane fouling.This article chooses polypropylene microporous membrane filter material to be basismaterial. Choose PVC and CS to be modifying agent and use the method of surfacemodification to change the hydrophilicity of the surface of membrane material. Choose staticwater surface contact angle and pure water flux to be the judgment indicators and use SEMobservations membrane surface morphology. Moreover, we studied the pollution behavior ofmodified membrane filter activated sludge mixed liquor.It shows that the greater the PVA concentration and the larger the membrane pore size,reducing the coating time, coating temperature and heat treatment temperature, chitosanweight was about0.5g, PVC and CS concentration ratio is about1, the glutaraldehydeconcentration of0.5wt%and the heat treatment time is60minutes can get a bettermodification effect and greater membrane flux. When the polyvinyl alcohol concentration is1.1wt%, the weight of chitosan is0.4g, glutaraldehyde concentration is0.5wt%, coating timeis100min, heat treatment time is20min can get the minimum static water surface contactangle. On the other hand coating temperature and heat treatment temperature have little effecton static water surface contact angle.Comparative study of the different properties of the membrane and found that before themodification, the surface of the basement membrane is very smooth, and the high porosity.After modification, the overall structure of the membrane has not changed, but the surface ofthe membrane is no longer smooth, surface roughness is increased, and while the surface ofthe membrane wrapped by some polymeric material membrane, pore size also reduces, andpure water flux decline, static water surface contact angle decreased. Modified membrane fouling membrane pores are blocked, surface of the membrane is covered by the sludge, themembrane fouling expressed as cake layer on the membrane surface contamination. Aftermembrane fouling, the pure water flux of modified membrane decreased, but still less than thebasement membrane before the modification.In filtered, study on modified membrane in activated sludge polluting behavior. We canfind that after each cycle the pollution of each membrane become more and more serious.And the most important factor is various. To the same basic membrane, the larger the borediameter of the membrane is, the easier it can be stopped by pollutant, and then lead to thedecrease of pure water flux. To PP and PVDF microporous membrane, if the membraneaperture is the same, PP microporous membrane is more likely to be blocked lead tomembrane throughput attenuation. Microporous membrane modified jam drag ratio are betterthan those of the basement membrane, while the modified layer of membrane hole has muchstronger resistance than that of the basement membrane.