| "Everything comes from water","The benevolent man delights in water, the wise mandelights in mountains". and the deterioration of water resources have already become a topicof many domestic and foreign research scholars values. Research and development ofmembrane bioreactor (MBR) technology has been40years, but the real application only morethan ten years, it is a new technology with biological treatment process of membrane filtrationtechnology combined with each other, however, MBR the membrane pollution problems inthis process is largely restricted operating mode. Therefore, it is very important to understandthe advantages and disadvantages of membrane separation technology, The optimization ofthe MBR membrane module, The selection and application of membrane material, Theinfluence factors of membrane fouling and prevention.The advantage of PVDF-HFM ultrafiltration membrane were high strength, corrosionresistance, thermal stability, good toughness so that it has been widely used in the MBR, butits low surface energy, strong hydrophobic, it will form impermeable layer in the process ofthe membrane. And it is easily adsorb pollutants in the MBR. In order to improve thepollution resistance of PVDF in MBR wastewater treatment process, in this paper, we use thelow temperature plasma modification methods to deal with PVDF-HFM to study thepollution resistance.Submerged membrane bioreactor treatment process has a small footprint, highconcentration of microorganisms in the reactor, resistance to shock loading, high-performancemembrane separation can achieve full automation and control and so on. In this paper,PVDF-HFM conducted five different modification methods, the use of SEM, FT-IR,mechanical testing, characterization of membrane water flux of the modified membranesurface properties of the original film; and analyze the MBR membrane fouling mechanism,the establishment of membrane fouling mathematics model; membrane fouling-resistantproperties and water effects analysis of modified hybrid plasma chemical vapor depositionfilm processing MBR with the original film negative pressure (siphon) sewage process; filmsof different modification methods modified from the original film in the MBR positive effectof water-resistant properties and sewage pollution treatment compression. Specificconclusions are as follows:(1) SEM and EDS spectrum of elements test showed that depositing a layer of a polymeron the membrane surface after the hybrid plasma chemical vapor deposition, the apparentdensity of the membrane pores is reduced; just after the plasma modification, the membranepores is difficult to find, the surface projections, roughness increases; and increase the surfaceoxygen content. FT-IR analysis showed that the mixed plasma chemical vapor deposition filmsurface modification plasma AA successfully grafted polymer. Analysis results by themechanical properties of hybrid plasma chemical vapor deposition modified membrane pliable best performance, And the modified membrane flux increased by12.04%-16.12%than modified membrane before modification.(2) The Research of fouling resistance about Mixed plasma chemical vapor depositionmodified membrane and the original film In the negative pressure (siphon) MBR, it is showedthat the static adsorption fouling resistance of the modified membrane is one-third time asmuch as the original membrane, In the motimo manufacturer recommended air-water ratio(20:1) operating conditions the cake layer of the modified membrane is thinner, flux decayrate is lower. After the hydraulic and chemical cleaning, the permanent irreversible foulingresistance of the original film is about five times as much as the modified membrane, it showsthat the modified membrane fouling resistance is better than the original membrane. Andaverage COD removal efficiency is87.04%,86.85%, The average removal rate of ammonia is75.08%,74.42%, Effluent turbidity substantially0NTU, it is showed that mixed plasmachemical vapor deposition modification has no effect on the accuracy of the membrane filter.(3) Research the fouling resistance about five different modification methods membranein MBR, the membrane static adsorption fouling resistance from small to large followed:MBR experimental results show that the critical pressure is more meaningful than the criticalflow rate, pressure distribution suitable for the analysis of critical membrane surface cakelayer, the critical pressure of "U" shaped PVDF-HFM membrane is10.8kPa, only plasmamembrane fouling resistant modified the best performance, the worst performance of theoriginal film resistant to pollution; after ultrasonic cleaning, a membrane flux recovery rate isthe highest, c membrane and original membrane flux recovery rate is the lowest, b\dmembrane rank only second to a membrane. COD removal efficiency of the modifiedmembrane and original membrane are90.0%-96.5%, water turbidity substantially are0NTU. |
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