Preparation Of Carbon Black-Based Ceramic Separation Membranes And Their Biodegradability For Diesel Oil

China is a country lacking of drinking water resources.Oily wastewater is one of the main pollutants in water body.The treatment and improvement of water quality is a hot research topic.Membrane separation technology has the characteristics of convenient operation,environmental protection and high efficiency,which makes it play an important role in the field of water treatment.However,there are some problems in traditional membrane separation,such as membrane fouling,the contradiction between membrane permeability and membrane selectivity,which seriously restrict the application of membrane separation technology in the field of oily wastewater treatment.In this paper,a ceramic separation membrane based on carbon black was designed and fabricated.The coupling of electrochemistry and membrane separation was realized by its conductivity.The selectivity and anti-pollution of the separation membrane were improved by electrochemical assistance.The mechanism of degradation of oily wastewater by the separation membrane under electrochemical assistance was explored.Carbon black ceramic separation membrane?CTM?were prepared by vacuum suction-high temperature sintering on Al₂O₃ ceramic substrates.The surface morphology,valence distribution and surface roughness of CTM were characterized by scanning electron microscopy?SEM?,X-ray photoelectron spectroscopy?XPS?,and Fourier transform infrared spectroscopy?FT-IR?.The results show that the surface of the prepared CTM is rough and irregular granular.Increasing the surface roughness can increase the surface area of the film and improve its electrochemical performance.XPS peak analysis of aluminum and carbon elements in CTM showed that the characteristic peaks of Al-O-C appeared in the spectra of aluminum and carbon,indicating that metal-oxygen-carbonization bonds were formed on the surface of the prepared carbon black ceramic separation membrane.The simulated oily wastewater?diesel oil?was treated by electrochemical catalytic oxidation with CTM as anode and titanium plate as cathode.The effects of pH value,current density,reaction time and electrolyte concentration on diesel oil removal rate or COD removal rate were investigated.The above factors were investigated and optimized by orthogonal test and single factor optimization method.The results show that catalytic oxidation with CTM electrode can effectively reduce the oil content in wastewater.Under the optimum experimental conditions,the distance between the electrodes is 10 mm,the pH value is 6,the current density is 20mA/cm²,the concentration of Na₂SO₄ is 15 g/L,the electrolysis time is 90 minutes,and the diesel oil removal rate and COD removal rate of the oil-bearing wastewater solution with initial concentration of 200 mg/L can reach 93.1%and 84.7%,respectively.The removal rates of diesel oil and COD were 63.6%and 53.4%respectively when the CTM membrane electrode was used to treat 1600 mg/L high concentration oily wastewater.Compared with the traditional metal electrode,the CTM membrane electrode had better electrocatalytic performance.In addition,in the process of CTM electrodes degrading oily wastewater under different conditions,the oil content of the solution varies with the reaction time,and the relationship between ln?C₀/C_t?and time t is obtained,which conforms to the first-order reaction kinetics.