Research Of Poly (Aryl Ether) Containing Heterocycle Moeity Composite Membrane And Its Application In The Wastewater Treatment

Contradiction between the water scarcity and the industrial water consumption overabundance is more and more severe.The membrane separation method of treating industrial wastewater is more and more applied.Among them,ultrafiltration and reverse osmosis membranes with dense separation layers play an important role in wastewater treatment.Development of thermal stable membranes is meaningful since it can further broaden membrane application fields,improve separation efficiency and spare energy.A integrated membrane process which named Ultrafiltration-Reverse Osmosis process is reviewed to treat organic wastewater with high concentration of acid and salt.It gets ideal result and shows that the grouping craft has abroad prospects and value in application.A UF membrane of poly(phthalazinone ether sulfone)(PPES) was chosen to pretreat organic waste water with high concentration of salt and COD instead of the traditional pretreatment.The experiments on the removal of organic substance and SS using ultrafiltration process were carried out,part of the COD was removed and the removal efficiency of SS can approach to 100%in ultrafiltration process.A part of organic substance would be removed in ultrafiltration process.The casting formula is PPES15.0wt.%,NMP 69.0 wt.%,HAc16.0wt.%,in which flux of treating wastewater gets to 25 L'm^-2·h^-1.Based on the pretreatment,the RO experiments for the treatment of the organic wastewater were carded out.RO membrane were prepared by interfacial polymerizing 1,3, 5-benzenetricarbonyl chloride(TMC) with m-phenylenediamine(MPDA) on the surfaces of PPESK support membranes.The best concentration of MPDA is about 1.20wt.%, concentration of TMC is about 0.12vet.%.The operating conditions(such as pressure, temperature and time) were studied in reverse osmosis process.The results indicated that the optimal operation pressure is 1.80 MPa.The permeation flux at 60℃is as 3 times as at 20℃in the first grade RO progress and the rejection rate keeps constant.The permeation flux declined smoothly in original 10d.PPESK membrane shows well anti- polluted.While in the second pass RO progress,the optimistic temperature and pressure are 50℃and 1.6MPa, respectively.According to the characteristic of the operation and the membrane fouling,different cleaning methods(cold water,hot water,acid lye and alkali lye to back washing) of reviving were used to membrane modules.The back-washing time was studied,and also compar ing the effect of the different cleaning.The best back-washing method was confirmed.The results indicated that the effect of chemical cleaning is better than water back washing.The best washing method is cleaning 45minutes with Na₂EDTA for ultrafiltration membrane and using the 1.0wt.%HCI and 1.0wt.%NaOH alternating cleaning 30minutes for reverse osmosis membrane.Compared with simple washing method,alternating cleaning method gets the better effect.