Design,Fabrication And Separation Performance Of Several Superwettability Membrane Materials For Oil/Water Emulsion Separation

Discharge of oily wastewater and frequent oil spill to human production and living and ecological environment caused serious harm.Due to the existence of a large amount of surfactant in water,the oil and water mixture is easy to form oil-in-water or water-in-oil emulsion,it is difficult to separate the oil/water emulsion in the traditional way.According to the above problem,this paper adopts a variety of simple method of preparing a series of infiltrating oil-water emulsion separation membrane materials,can effectively overcome the above problem The main research content is as follows:（1）A robust superhydrophobic mesh was prepared by a facile spraying Octadecyltrimethoxys modified attapulgite suspension combined with inorganic adhesive on mesh.The as-prepared meshes show eminent superhydrophobicity and acquire a gravity driven water-in-oil emulsion separation with efficiency above 99.7%and flux above 106.7 L m^-2h^-1 even after multiple cycles.In addition,the meshes exhibit robust and stable superhydrophobicity with water contact angles above 150°after 200sandpaper abrasion（transverse shear force）and harsh sand impact（longitudinal impact force）cycles,and meanwhile,still maintain outstanding emulsion separation performance during tests.（2）Pine nut shell waste material is a common life waste.We will through the pine nut shell lignin,pine nut shell cellulose,and then use a simple suction filter method for underwater superoleophobic pine nut shell cellulose（PNSC）membrane,and has realized the separation of oil-in-water emulsion The membrane filter with multi-stage rough structure and properties show the underwater super hydrophobic oil,oil contact angle in more than 150°At the same time can be for a variety of oil-in-water emulsion separation,and the separation efficiency were above 99.3%In addition,the membrane can be used in all kinds of corrosive mixture of acid alkali and salt solution and the separation of good chemical stability.（3）Inspired by desert beetle water collection capacity in air,a desert beetle-like composite membrane structure was constructed achieve oil capture in water,thus improving the separation performances of the surfactant-stabilized oilin-water emulsion.The as-prepared nanofibrous membrane consists of hydrophobic/oleophilic ZIF-8bumps and underlying underwater superoleophobic polyacrylonitrile（PAN）,and possesses a similar structure to desert beetles but with opposite wettability.In the process of emulsion demulsification,besides the sieving effect of the underlying traditional underwater superoleophobic PAN membrane,the bumpy oleophilic ZIF-8particles of the composite membrane can capture oil,thus strengthening the demulsification ability of the membrane.Furthermore,the separation efficiency of the inverse desert beetle-like membrane is up to 99.9%for surfactant-stabilized oil-in-water emulsion,which is superior to that of traditional single underwater superoleophobic PAN membranes lacking the hydrophobic bump structure.Moreover,for light oil-in-water emulsion,the permeation flux also increases because the captured tiny oil droplets can aggregate subsequently and grow large enough to detach from the underlying surface which greatly reduces the incidence of filter cake formation and congestion.