Study On Performance Of Microbial Fuel Cell Incorporating Up-flow Constructed Wetland For Pig Farms Biogas Slurry Treatment And Bioelectricity Generation

In this paper,a microbial fuel cell coupled with up-flow constructed wetland was build as the reactor to study the system's electric performance and pollutant removal efficiency during start-up period;the system's the treatment effect when deal with simulate the pig farms biogas slurry under different hydraulic retention time;the system's pollutants removal efficiency and the resistance under different external resistance condition at the best HRT;the system's wastewater treatment effect along the reactor height in the open circuit and closed circuit mode under different external resistance condition at the best HRT.The main conclusions are as follows:The output voltage of the start-up period was stabilizing at 550 mV,system's COD_cr and ammonia nitrogen average removal rate were 89.17%and 58.07%respectively;The dissolved oxygen concentration of effluent is 3.84 mg/L;PH swings between 6⁸.When HRT is 36h,24h,48h respectively,the 48 h can be determined as the best HRT according to the various pollutants index removal rate size of the system.From the polarization curve and power density curve,we can be sure that the the open circuit voltage of system was 561.0mV;the output maximum power density of system was 61.98 mW/m3.Based on polarization curves of linear fitting,the fitting curve equation was y=-420.27x+0.553 and the fitting correlation coefficient was0.93258 and the apparent resistance was 420.27?.Resistance was selected in 450ohms,250 ohms,150 ohms,50 ohm and measured from small to big value.Based on the system of various pollutants index,we can determine best outside the resistance of the device was 150?.Under the open circuit and closed circuit mode,the change rule of effluent's dissolved oxygen concentration along the reactor was similar.The bottom place of reactor was anaerobic condition,the The middle section including aerobic,anaerobic and anoxic environment,and upper part of reactor was aerobic condition.Under the condition of closed-circuit effluent COD_cr,ammonia nitrogen and total nitrogen removal rate is higher than open circuit conditions 1.6%,10.73%,11.34%respectively.For the accumulation of nitrate in the process of denitrification reactor,the final effluent concentration of nitrate were 1.28 mg/L and 1.16 mg/L;the acidity-alkalinity of effluent is neutral when the system was operated at open circuit and closed circuit mode.