Preparation And Properties Of Nanofibrous Membrane Material For Water Treatment

Currently,the increasing scarcity of fresh water resources has become a serious problem in today's world.There are two methods to ease the shortage of water resources,means increasing water resources and clean waste water.In the revenue side,it is an important research direction to develop a reverse osmosis(RO)membrane for desalination.The base material which is commonly used in the preparation of the RO membrane generally has a high mass transfer resistance,low porosity and a lot of dead-end pores.Electrospun nanofibrous membranes do not require very large pressure to achieve higher throughput because they have high porosity.In this way,they can work efficiently and save much energy.In this paper,electrospinning technology was used to prepare a base membrane.The material of the base membrane is polyethylene terephthalate(PET),which is widely used in industrial fields and has excellent physical and chemical properties of the film as a base material.Then composite RO membrane was prepared by interfacial polymerization.Polymerization monomers and conditions have an impact on the morphology and filtration performance of the polyamide thin film.What's more,the amount of surface active agent added to the aqueous phase has a crucial influence on the uniformity of the thin separation layer.A composite RO membrane with high rejection rate and throughput is prepared by adjusting the conditions.In terms of clean waste water,dyeing wastewater has a large proportion of effluent discharge.In this paper,an efficient membrane for dyeing wastewater treatment was prepared.PET and PES were prepared together to be well combined.Finally PES was prepared alone as the upper filter layer.NMP/H₂O was used as a mixed solvent to immerse the PES nanofibers innovatively to get a dense layer.This layer can effectively filter the indigo particles.Combined with the unique properties of electrospun membranes,the composite membranes have excellent reusability but low flux.To improve the flux of PES/PET composite membrane,the surface of membrane was oxidize modified.After oxidation,the water flux of the membrane was significantly increased.The recycling situation vary a lot between modified films obtained by different oxidant concentration since the membrane fouling and cleaning situation is too complex.