The Study Of Electrogenesis And Wastewater Treatment On Microbial Fuel Cell Combined With A~2/O

Microbial fuel cell is a new biological treatment technology converting organic wastewater into electricity with microorganism. This paper designed a device what MFC combined with A2/O in order to make the technology can be successfully applied to practical wastewater treatment, and to achieve the purpose of generate electricity at the same time in the treatment of sewage. The start-up and condition optimization of the coupled system was studied, and investigated it treating domestic wastewater and producing electricity in the same time.The coupled system stated-up successfully after running for 37d. The system reached the maximum average voltage of 574mV and the internal resistance of 381Ω, and power density of 0.0396 W·m-3. The effect was outstanding of the treating domestic wastewater, the average COD and ammonia removal efficiencies were 92.9% and 72.1%, respectively. The concentration of NO2-N and NO3-N were 4.41mg·L-1 and 16.41mg·L-1, respectively.Aiming at increasing performance of power generate and efficiency of treating domestic wastewater, the effect of C/N on the electricity production and wastewater treatment efficiency was studied. The coupled system achieveed the maximum voltage of 550mV, both of the COD removal efficiencies were 96.1%-97.1%, and few effect with ammonia when C/N was 4.2. The NO2-N and NO3-N were the minimum in effluent of 9.35mg·L-1 and 2.31mg·L-1, respectivelys and the removal rate of TN were the maximum of 57.9% when C/N was 6. The results showed that the coupled system reached optimum performance when C/N was 4.2.In the test on HRT for the coupled systemm, the results showed that the longer of HRT the output voltage was smaller, however, the removal rate of COD and NH3-N was higher. The removal rate of COD was constant after HRT was 20h and reaching the maximum of 98%, the removal rate of ammonia was 90%. The concentration of NO3-N was the minimum around 10mg·L-1, and the removal rate of TN was maximum of 72.3% when HRT was 20h. Taking into account of voltage and removal efficiencies, the coupled system achieved optimum performance when HRT was 18h.Then, the performance and removal efficiencies of coupled systems treating practical domestic wastewater was studied. The system reached the maximum average voltage of 469mV and the internal resistance of 337Ω, and achieved the maximum power density of 0.0310W·m-3 after running 21d. The maximum removal efficiencies of COD and TN were 88.6% and 78.5%, respectively. The results showed that the effect of treating practical wastewater significantly, at the same time produced electrical was considerable with the coupled system.Scanning electron microscope and aommounity analysis showed that the big difference of the species and quantity of microorganism on cathode and anode. The variety of electrogenesis bacteria were enrichment on anode and the high abundance of denitrifying bacteria were on cathode.