Design And Research Of Electrocatalytic Carbon Membrane Reactor Used For Sewage Treatment

With the rapid development of industrial society,industrial products are increasingly rich day by day.but the environmental pollution problems which induced can not be ignored.The massive discharge of industrial wastewater has brought great disaster to the environment.Seeking for efficient and low-energy sewage treatment technology has always been a hot topic in the field of chemical industry.Conventional water treatment technology mainly include photocatalytic oxidation,electrocatalytic oxidation method,a membrane seperation method,biological method and the like.The photocatalytic oxidation and electrocatalytic oxidation method can better degrade organic matter in sewage,but consume too much energy.Which large-scale industrial applications are limited by the economic costs.biological methods require very high reaction conditions.which has no processing capacity to the high toxic wastewater basically.Maintenance costs limit its applicaton.Membrane separation technology is widely used in separation field,but there are also concentration polarization,membrane fouling and other issues,and the separation function is so simple that can not degrade pollutants.On the other hand,the composition of sewage is becoming more and more complex,a single sewage treament technology has not been competent for the degradation of the complex wastewater,therefore,multi-technology combination is the development trend of sewage.In this paper,the microfiltration membrane separation technology was designed with the new type of porous carbon material,coal-based carbon membrane,which combined the electrocatalytic oxidation technology,a new technology-“membrane separation-electrocalytic oxidation” came into being.This technology can be used for refractory wastewater with low energy consumption and high degradation efficiency.The sealed and hollow plate of carbon membrane was used as the microfiltration equipment in the reactor.The microfiltration equipmen deal with the sewage under the negative pressure,at the same time,the carbon membrane plays as the anode of electrocatalytic oxidation.Stainless steel mesh serves as cathode.The pollutants deposited on the pore surface are degraded under voltage.The caculation of hydraulic characteristics of the reactor shows that the flow state inside the carbon membrane is moderate diffusion(Dispersion is 0.218),slightly bias towards ideal flow(Morrill Index is 3.71).Internal dead zone percentage is 6.7%,The dead zones mainly exist in four right angles of the carbon membrane.The electrocatalytic membrane reactor has a better effect on wastewater simulated by Phenol.The experimental results indicate that 2V's electrocatalytic voltage has a good degradation of pollutants and the energy consumption is low.The longer the hydraulic retention time(HRT)is,the better degradation efficiency,but the shorter hydraulic retention time is able to exert turbulence to a certain extent and improve the degradation rate.The effect of phenol wastewater treatment under acidic and alkaline conditions is better than that under neutral conditions.The electrode spacing has little effect on the treatment effect in a small range.Carbon membrane in the long-time water treatment will gradually fail since the active site of the carbon membrane is gradually covered by contaminants.The failed carbon membrane can completely restore its water treatment performance by carbonization regeneration.The failure curve of carbon membrane shows that the degradation of pollutanta has a great relationship with the absorbtion properties of carbon membrane.Adsorption experiments show that the adsorption equilibrium of carbon films accords with Langmuir isothermal adsorption equation.The adsorption rate is in accordance with the pseudo-second-order kinetic adsorption equation.The failure curve of the carbon membrane is defined as the "adsorption-electrocatalytic" breakthrough curve,According to the reaction rate constant and the adsorption equation,the failure model of the electrocatalytic carbon membrane and the breakthrough curve equation can be calculated.