Research On Enhancing Treatment Of Ship Domestic Sewage By Electro-coagulation

Membrane Bioreactor(MBR)has significant advantages in the treatment of marine sewage because of its small footprint and strong decontamination capacity.However,as the IMO improves the standards for the discharge of ship domestic sewage,the problem of unsatisfactory removal of nitrogen and phosphorus from MBR has become one of the current research hotspots.Electro-coagulation technology has a reliable treatment effect and rapid processing ability,and is widely used in the phosphorus removal treatment of sewage.Electro-coagulation technology has been widely used in wastewater treatment due to its high efficiency of phosphorus removal and rapid processing capabilities.In this research,the object of treatment is ship domestic sewage,through the electro-coagulation enhancing MBR dynamic test and electro-coagulation static test,the influencing factors and the decontamination performance were examined,the measures to delay the passivation of the polar plates was thoroughly explored.The influence factors of the electro-coagulation process were studied through static tests,and the effects of electrolysis time,current density,p H,and chloride ion concentration on the removal efficiency of pollutants were investigated.The results show that electrolysis time,current density,and p H are the main factors affecting the decontamination efficiency of electro-coagulation.In the optimal working conditions,the effect of electro-coagulation on TP removal was significant,reaching over 90%.In order to study the interactions between influencing factors,a multiple regression analysis model was established by response surface methodology.The results show that the interaction between the electrolysis time and the current density is significant.In order to investigate the enhancing effect of electro-coagulation on MBR,a comparative analysis of MBR and electro-coagulation MBR dynamic tests was conducted.The results showed that the effect of electro-coagulation on the phosphorus removal efficiency of MBR was significant,the concentration of TP was decreased from 5.66 mg/L to less than 1 mg/L.The effect of enhanced removal of ammonia nitrogen and CODCr was not significant.In order to examine the effect of electro-coagulation on the properties of the mixed liquor,the properties of the mixed liquor were tested.The results showed that electro-coagulation caused a significant increase in the concentration of suspended solids in the mixture,and had no significant effect on the conductivity of the mixture.In order to investigate the effect of electro-coagulation on activated sludge,the activated sludge was analyzed by scanning electron microscope and energy spectrum.The results showed that electro-coagulation can improve the flocculation and sedimentation effect of activated sludge.Scanning electron microscope and energy spectrum analysis were performed to observe the morphology and composition of the passivation of the plate surface.The results show that the longer the reaction time,the more holes are formed on the surface of the plate by active anions,the greater the oxygen content on the surface of the plate,and the more severe the passivation of the plates.The passivation test was conducted to examine the influence of the power supply form and the active anion on the passivation and energy consumption of the electrode.The results show that alternating current and adding active anions can delay electrode passivation and reduce energy consumption.