The Technoligies Of Saline Wastewater Treatment Coupled With Electricity Generation And Nitrogen And Phosphorus Removal Using Microbial Fuel Cell

Ammonia nitrogen and phosphate have been included in the total pollutant discharge control system of China's "13th Five-Year" environmental protection plan,and it is particularly important to discharge the sewage after treatment.Wastewater treatment is a high-energy consumption industry,and the wastewater contains a lot of energy,just like a huge "energy storage tank".Therefore,the recycling and purification of energy in wastewater is of great significance to reduce energy consumption.Microbial fuel cell(MFC)is a device in which electricigens oxidizie organic matter to convert chemical energy into electricity.In this paper,a coupling system for MFC electricity generation and wastewater purification is established,which uses electricity-generating microbial chemical energy to convert electrical energy,while using moderate halophilic bacteria as a power-producing strain to provide anti-reverse assistance in high-permeability environment and improve pollution in wastewater and reduce removal efficiency of the object.It is expected to solve the problems of poor adaptability of wastewater produced by MFC in the wastewater,low power generation efficiency,and unsatisfactory removal of pollutants.It is a new technology for achieving efficient energy recovery and purification of wastewater.In this paper,a single-chamber MFC system was constructed.The activated sludge from the primary sedimentation tank of the wastewater treatment plant was used as the MFC matrix,and a dominant strain S01 with the ability to produce electricity and denitrification was isolated and screened.It was identified as the genus Shewanella and was named Shewanella sp.S01.The optimal conditions for MFC production of Shewanella sp.S01 were investigated.The optimal production matrix was MF55,the optimum concentration of sodium acetate was 3.6 g/L,the optimum temperature was 30?,and the initial pH of the electricity-producing matrix was 9;The effect of the additional electron intermediaries on the electricity production of MFC is that riboflavin is the best electron intermediator.The open circuit voltage of MFC is increased by 35.2%and the internal resistance is reduced by 60.0%.The Shewanella sp.is verified and inspected.The anaerobic denitrification capacity and influencing factors of S01:sodium acetate is the optimal organic carbon source,the optimum initial pH of anaerobic denitrification is 9,and the optimum C/N ratio is 10.A number of moderately halophilic strains were isolated from the sediment of a salt pond in Dalian,and 14 of them were identified as Halomonas.The strain H12 with nitrogen and phosphorus removal function was screened out and identified as Halomonas sp.H12.The nitrogen removal and phosphorus removal conditions of Halomonas sp.H12 were optimized by response surface methodology.The nitrogen and phosphorus removal processes were studied under comprehensive optimization conditions.The nitrogen removal and phosphorus removal rates of the strains were as high as 78.5%and 49.2%,respectively.It provides an important theoretical basis for future research on industrial high-salt wastewater treatment.Establish a coupling system for MFC electricity generation and wastewater purification in high-salt wastewater.The enhancement effect of Ectoine on the electricity production of Shewanella sp.S01 under high salt was investigated.It was proved that Ectoine has anti-reverse assisting effect on MFC production under high salt.When MFC was enhanced with Halomonas strain for power generation and wastewater purification,the efficiency of power generation and pollutant removal was significantly increased under high salt and high nitrogen and phosphorus matrix.The output voltage and nitrogen removal rate were 10.1 times and 1.4 times higher than those without Halomonas strain.That is,Ectoine secretory strain Halomonas salina DSM5928 can provide antiretroviral assistance for Shewanella sp.SOl.Based on this,this paper proposes a model for salt generation,transmission and acquisition in MFC,and reveals the salt tolerance mechanism of MFC coupling system.The nitrogen and phosphorus removal strains can provide MFC with efficient pollutant removal.Therefore,the coupling system has important theoretical and practical value.