The Preparation Of Polysulfone Membrane And Application On Landfill Leachate Treatment

Because of the good permeability,thermal stability,solvent stability and goodstrength,polysulfone(PSF) membranes have been widely used in many fields,such as ultrafiltration,microfiltration,reverse osmosis, liquid/liquid or liquid/solid separation,gas separation,hemodialysis, wastewater treatment and so on.Polysulfone(PSF) ultrafiltration membranes were prepared from a series of casting solutions with different composition by phase inversion process.Polyethyleneglycol(PEG)/N-Methyl-pyrrolidone(NMP)were used as casting solvent and water was used as coagulant.The resulting membranes prepared by changing the polymer concentration(in the range of 14-18wt%),the molecular weight(600,800,1000Da)of PEG additive and the ratio of PEG were characterized by mechanical 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.The membrane surface texture does not have the hole structure,but the cross section structure changes by the loose lodging's fingered structure to the compact fingered hole.On the other hand,an UF membrane from a dilute polymer solution produced a thin skin layer,leading to a high value of flux but a relatively low percentage of rejection for PEG.The experimetal parameters are investigated by using orthoanal experiment.Based on the experiment results,the optimized PSF membrane is made.In order to strengthen the hydrophility of Polysulfone ultrafiltration membrane surface and rise its anti-fouling property,hydrophobic polysulfone membranes were modified by UV irradiation in 500ml/l ethanol.The structure and conformation carryout does not monomer of membrane on Its surface was characterized by strength of break,contact angle,FTIR,SEM and flux.The results showed that the strength of break reduces and their hydrophilicity increased with increasing in irradiation time.The water flux of menbranes which was irradiation goes up and retention reduce greatly.The contact angle of grafted membrane surface reduces,which show that the hydrophilicity of membrane surface strengthened.FTIR analysis confirmed that new functional group was grafted on the membrane surface.SEM experiment approved that the grafted chain was on the surface not within the pore.Ultrafiltration membrane is employed for removal of COD and turbidity in the landfill leachate.The experimental results that mean removal rate of COD is over 63%,the turbidity can be removed 90%.The operated pressure AP=0.06MPa was selected,and the gel layer model of disposing wastewater has been found,the equation isâ–³P/(μ·Jw)=0.14153×10¹²V+10.51429×10¹²The research results provide a theroy basis for the optimization for preparation of PSF membrane and for the improvement and enhance of the performance of membrane.It also provide a prospect for the application of ultrafiltration membranes on leachate treatment.