Construction Of Carbon Based Nanofiber Composite Membranes And Purification Of Oily Wastewater

The discharge of industrial and domestic oily wastewater has brought great harm to the ecological environment.How to separate oily wastewater efficiently and green has become a research hotspot.The traditional oil-water separation method is miscellaneous,high cost and even secondary pollution,so it is not an ideal scheme for oil-water separation.The film material with special wettability has special wettability to oil and water,and has the advantages of green,simple and efficient.Although the special wettability film material has natural advantages for the separation of oil-water mixture,it can not separate the soluble organic matter dissolved in water.In addition,the film has a single wettability,which can not deal with different oil-water mixture.Intelligent response wettability materials can achieve wettability conversion(such as pH response,light response,electric field response,etc.),but there are some problems such as complex preparation process,long response time and high operation requirements.In this case,in this paper,zinc oxide(ZnO)was loaded on the surface of carbon fiber by electrospinning carbon fiber,which gave the film the ability of photocatalysis.The composite film was modified by stearic acid,and the quick and simple wettability conversion of the film was realized.The specific research is as follows:1)Carbon fiber films were prepared by electrospinning and carbonization,and then modified by octadecyl triethoxysilane to enhance its hydrophobicity.Janus ZnO/carbon fiber composite films were synthesized by one-sided oxidation and potential enhanced hydrothermal treatment.2)The effects of conductivity,oxidation treatment and potential enhanced hydrothermal treatment on the morphology of ZnO were discussed through the construction of galvanic cell.It is concluded that every step is the necessary condition for the uniform growth of ZnO on the surface of carbon fiber.The main strong peak of potential enhanced hydrothermal method is(101)crystal plane,which indicates that ZnO is oriented growth.3)The different wettability of Janus film surface gives it good oil-water separation performance.Due to the photodegradation performance of ZnO,the film can degrade the soluble organic matter after oil-water separation;The results show that the flux of dichloromethane,n-hexane,carbon tetrachloride and hexadecane is 18076 lm-2h-1,12885 1m-2h-1,10637 1m-2h-1,11514 1m-2h-1 respectively.With the increase of hydrothermal time,the flux also decreases,and the separation efficiency is more than 99%.4)The film was modified by stearic acid and UV irradiation to achieve unidirectional transmission performance.The hydrophobicity of ZnO surface was further enhanced by prolonging the modification time.The reversible conversion of wettability of the film was realized by using the high solubility of stearic acid in tetrahydrofuran.The flux of the composite film did not decrease significantly after stearic acid modification.Figure[34]table[7]references[112]...