| Polyethersulfone(PES) ultra filtration membranes were prepared from a series of casting with different composition by phase inversion process. Dimethylacetamide(DMAc)/Polyvinylpyrrolidone(PVP) K30 were used as casting solvent and water was used as coagulant.The resulting membranes prepared by changing the polymer concentration(in the range of 14-22wt%)and the ratio of PVP were characterized property,scanning electron microscope observations,measurements of water flux and rejection.Results showed that the flux of the membrane decreased while the separation performance for particle solutes increased with an increase in polymer concentration.This means that the outer skin layer of the membranes became apparently thicker and denser with increasing polymer concentration.On the other hand,an UF membrane from a dilute polymer solution produced a thin and porous skin layer,leading to a high value of flux but a relatively low percentage of rejection for PVP.The experimental parameters are investigated by using orthoanal experiment based on the experiment results;the optimized PES membrane is made.In order to enhance the polyether sulfone ultra filter diaphragm's water affinity performance,enhances its anti-pollution however nature,to tested the polyether sulfone membrane which prepared to carry on the modification.In the self-made polyether sulfone ultra filter diaphragm's foundation,an increase different content's cellulose acetate carries on the blending modification,seeks for the best modified condition,changed the polyether sulfone membrane structure.Mainly inspected the cellulose acetate increase to the polyether sulfone performance structure influence, through superficial angle of contact methods and so on cryoscopy, scanning electron microscope,modified membrane's pure water flux and interception performance attributes around modified the structure performance change situation.Research surface:Increases the different cellulose acetate content through the test,has discovered when increases 2%cellulose acetate,the modified membrane's flux and the interception rate achieves the optimum condition,has served the modified purpose.Through the above craft preparation's polyether sulfone ultra filter diaphragm,uses in the Sewage treatment plant sanitary sewage and industrial waste processing.This experiment as tests the water used take the Songjiang District new town Sewage treatment plant aeration tank's sewage.Inspected around the modified seepage flux,has studied the ultra filter diaphragm in the elimination waste water aspect and so on COD, turbidity,chromaticity performance.Experimental result surface:The seepage flux changes gradually along with the running time is small,but is slightly small after the modified membrane flux reduction scope;The ultra filter diaphragm to the COD elimination rate is above 80%,the turbidity elimination rate is above 98%,to the chromaticity elimination is above 80%.Andt after both membrane clean,the restoration ratio achieves above 78%.The reason of the two membranes fouling is investigated by membrane resistance determination in membrane bio-reactor;it is found that membrane fouling mainly result from concentration polarization and gelatin layer.The dead-end filtration of sludge reflects the mechanism of membrane fouling,and it is in street conformity with the cake filtration law.It verifies the Membrane fouling is mainly caused by deposit on membrane surface to scan the electric mirror photo.The research results provide a theory basis on the optimization of preparation for PES membrane and for the improvement of the membrane performance.It also provides a prospect for the application of ultra filtration membranes on wastewater treatment.
|
PDF Full Text Request