Study On Phosphorus Removal Performance From Domestic Sewage By CW-MFC Coupling System

This experiment aims at the problems of water resources pollution,water eutrophication and energy shortage in China.Laboratory research is the main method.Construction of a microbial fuel cell system coupled with constructed wetland for wastewater treatment and power generation.Taking the total phosphorus in artificial simulated domestic sewage as the treatment target,the optimal phosphorus removal effect and electricity production were found by comparing the operating conditions such as matrix,hydraulic residence time and so on.The phosphorus removal mechanism was preliminarily analyzed by measuring the phosphorus content along the process.Through the kinetic experiments,three kinds of matrix were screened,magnesia and garnet were selected as the experimental matrix.The results show that the maximum theoretical adsorption capacity of garnet and magnesia is 1.675mg/g and 2.3285mg/g respectively.The phosphorus adsorption process of the two kinds of substrates was in accordance with the quasi second-order kinetic model,Langmuir isotherm and Freundlich isotherm.Set four different concentrations of influent pollutants.Two groups of systems with different substrates operate together.With the increase of hydraulic residence time,the removal rate of phosphorus in CW-MFC system of magnesia and garnet is on the rise.The longer hydraulic residence time is,the better the phosphorus removal efficiency of the system.When the influent phosphorus concentration is 1mg/L,two systems have the highest removal efficiency of total phosphorus,80.3% and 92.4% respectively.The phosphorus removal efficiency of garnet-based system is significantly higher than that of magnesia-based system.Comparison of phosphorus removal efficiency between CW system and CW-MFC system.The results show that the phosphorus removal efficiency of CW system is obviously lower than that of CW-MFC system.With the increase of influent phosphorus concentration,the difference of phosphorus removal efficiency between CW system and CW-MFC system increases gradually.The maximum removal difference of garnet group was 19% when the influent phosphorus concentration was 5mg/L,the maximum removal rate difference of magnesia group is 22.5%.Automatic monitoring of power generation voltage of two systems,with the increase of pollutant concentration in the influent,the power generation voltage first increases and then decreases.When the influent phosphorus concentration is 2mg/L and COD concentration is 460mg/L,the power generation performance of CW-MFC system is the best.The maximum stable voltage of garnet assembly is 500 mV,and that of magnesia assembly is 290 mV.Figure 40;Table 8;Reference 85...