Electrocatalytic Mesoporous Filtration Membrane For The Treatment Of High Salt Direct Red 31 Wastewater

The membrane separation is a kind of technology which uses chemical bit difference or external energy as the driving force to finish the separation,grading,purification and enrichment of mixtures.It also separates the components in a mixed solution by using the selective transmittance of membranes.This technology has many characteristics such as high separation efficiency,cleanness,no pollution,no phase change and easy operation.It has been widely and effectively used in water preparation,seawater desalination,water supply and drainage treatment and other environmental protection fields in recent years because of its rapid development.During the development of membrane industry,there are many reasons restricting the development and application of membrane separation technology all the time,one of them is the anti-pollution properties of organic membranes.During the process of membrane separation,organic materials are easy to attach to the membrane surface forming a cake layer,and can block the pores of the membrane,which greatly affects the organic membrane flux and reduces the life of the organic membrane.Therefore,how to mitigate membrane fouling is a very important research direction in the field of membrane separation.At present,physical cleaning and chemical cleaning are the commonly used methods,easing the membrane fouling.While,this process will greatly increase the cost and reduce the separation efficiency.Electrocatalysis called environmentally friendly catalytic oxidation technologies can decompose organic pollutants into small molecules organic matter or directly degrade into water and carbon dioxide.In order to solve the problem of membrane fouling and increase the membrane’s life,this article focuses on the combination of electrocatalytic technology and membrane separation.In this paper,two kinds of polyether sulfone ultrafiltration membranes were prepared by adding two kinds of different electric catalysts with carbon cloth as support.And then use it as the basal membrane,while chitosan as aqueous monomer,benzoyl chloride(TMC)as organic phase monomer.The electro-catalytic mesoporous membrane was prepared with ultrathin functional layer forming on the surface of substrate by interfacial polymerization.Polyether sulfone electric catalytic organic membrane was prepared with polyether sulfone as polymer,dimethylacetamide as solvent,polyethylene pyrrolidone as additive,and polyether sulfone electric catalytic organic membrane was prepared by adding conductive polymer and electrochemical catalyst in casting membrane solution with the method of phase inversion.Among them,two different catalysts are Co-N-C and Pt/CNTs.Two kinds of polyether sulfone electric catalytic organic membrane containing different catalysts were characterized by EDX,SEM,XRD,XPS,CV and so on.The results showed that Pt/CNTs electro-catalytic mesoporous membranes contain polyaniline,Sb-SnO2 and Pt/CNTs,Co-N-C electro-catalytic mesoporous membranes contain polyaniline,Sb-SnO2 and Co-N-C.The surface is uniform,smooth and flat,and the cross-section has a uniformly distributed finger hole.The top layer forms a ultrathin and dense functional layer.The average aperture is less than 2nm.In this experiment,the direct red 31 dye was selected as target.Several process parameters affecting membrane separation process were studied.The experimental results show that when the transmembrane pressure difference is 0.3 MPa,the voltage is 8.0V,the salt content is 8%,and the initial dye concentration is 20mg/L,the solution pH is 6,Pt/CNTs electro-catalytic mesoporous membrane performs better in the degradation of direct red 31 dye.When the transmembrane pressure difference is 0.4 MPa,the voltage is 8.0V,the salt content is 8%,and the initial dye concentration is 20mg/L,the solution pH is 6,Co-N-C electro-catalytic mesoporous membrane performs better in the degradation of direct red 31 dye.Compared with the process of separate membrane separation,the electro-catalytic mesoporous membrane flux has been improved,and the electro-catalysis process has greatly degraded the fouling on the membrane hole and membrane surface,which has relieved the membrane fouling to a large extent.Under the condition of the experiment,the interception rate of direct red 31 dye is more than 98%,the permeation liquid is colorless and transparent,the retention rate of inorganic salt NaCl is below 1%,and the separation of salt and organic matter is realized.