Simultaneous Treatment Of Two Different Wastewaters By Photosynthetic Microbial Fuel Cell (PMFC)

With modern social pollution problems and energy shortages becoming more and more serious,the use of traditional sewage treatment methods requires a large amount of energy,and different types and properties of different wastewaters need to be disposed separately.Therefore,it is necessary to seek a high efficiency,low operating cost and energy consumption and adaptable sewage treatment technology.Microbial fuel cell?MFC?can directly convert energy from organic waste into electrical energy,which has dual functions of power generation and waste disposal.However,MFC has a good treatment effect for simple and easy-to-treat pollutants,and the treatment effect for some refractory pollutants still needs to be improved,which is far from the realization of large-scale industrial application.To broaden the application prospect of MFC in refractory wastewater treatment,a dual-chamber MFC was designed based on the principle of microbial fuel cell and related research literature.In the MFC anode,the laboratory-preserved photosynthetic bacteria PB-Z was used to treat starch wastewater with high COD concentration?about 12,000 mg/L?with the assistance of solar energy,and the laboratory-preserved heterotrophic nitrifying bacteria Alcaligenes sp.C16was used in the cathode to treat nitrate wastewater without organic carbon source?initial C/N is 0,simulating groundwater contaminated with nitrate?.Through the optimization of a series of factors in the MFC system,the reaction time was shortened and the treatment efficiency was improved,and the utilization of solar energy,efficient simultaneous degradation of high-concentration starch wastewater and nitrate wastewater?including low C/N ratio and even no organic carbon source?and energy utilization in organic pollutants were realized.It provided some inspirations and references for the application of microbial fuel cells in wastewater treatment.On the cathode side,by selecting the best external resistance to 500?and adding the optimal concentration of 1 mmol/L of Cu²⁺to the cathode,the removal rate of nitrate at a C/N ratio of 0 was improved,and the problem of nitrite accumulation was solved.In the aspect of battery anode,the removal efficiency of anode COD and cathode nitrate in MFC was improved by determining the optimum anode nitrogen source with ammonia nitrogen,the optimum concentration of nitrogen source as6 mmol/L,the optimum illumination condition as continuous illumination and heating and stirring in the anode chamber.While improving the battery conditions,the hydrogen production of PB-Z from starch,the denitrification of C16 in the absence of carbon source,open-circuit and closed-circuit batteries were studied.The feasibility of the MFC constructed in this paper was verified.After the battery was operated for a period of time,for the aging of the anode and cathode strains,it was determined that the cathode was filled with 60%v/v of the membrane-activated activated carbon and the anode was filled with 30composite bacteria to complete the supplement and improvement of the MFC strain.