用夹子将质子交换膜和载铂量为0.2 mg/cm^2碳纸固定在阳极室的短臂端口构成短臂型空气阴极微生物燃料电池.利用污泥电池从厌氧消化污泥中富集产电菌于石墨棒表面,循环伏安法检测发现这些微生物具有电化学活性.将富集好的石墨棒作为阳极用于短臂型空气阴极微生物燃料电池,以醋酸钠为底物时该电池的最大功率密度为738 mW/m^2,内阻为280Ω,开路电压为741 mV.连续向阳极室通氮气和去掉质子交换膜可分别将电池的最大功率密度提高到745 mW/m^2和759 mW/m^2,当两者同时作用时最大功率密度可达到922 mW/m^2,而这3种条件下电池的内阻仍保持在280Ω左右.当底物浓度在12.62~100.96 mg/L、外电阻为510Ω时,电池的最大输出电压和底物浓度之间存在明显的线性关系(R^2=0.99).当底物浓度高于100.96 mg/L时,电池的最大输出电压不再增大并保持在302 mV(外电阻为510Ω).然而,电池的库仑效率则随着底物浓度的提高而提高,从31.83%逐渐增大到45.03%.
The short-arm air-cathode microbial fuel cell(ACMFC) was constructed using a cramp to fix the proton exchange membrane(PEM) and carbon paper with 0.5mg/cm^2 onto the short-arm side of the anode chamber.Exoelectrogens on the surface of graphite rod were enriched by a sludge microbial fuel cell from the anaerobic digestion sludge.And the cyclic voltammetry result showed these microbes had electrochemical activities.Using the graphite rod covered by exoelectrogens as the anode and sodium acetate as the substrate,the short-arm ACMFC showed a maximal power density (Pm) of 738(mW/m^2),internal resistance (Ri) of 280Ω and open circuit voltage(OCV) of 741 mV.Continuous sparging the anode chamber with nitrogen or removal of the proton exchange membrane enhance the P_m of the cell to 745(mW/m)2and 759 (mW/m^2) respectively.When both of the two measures were used together,the P_m reached up to 922(mW/m^2).Under these three conditions the Ri of the cell was kept around 280 Ω.When the substrate concentration was 12.62-100.96(mg/L) and external resistance was 510 Ω,the maximal voltage of the cell and the substrate concentration showed an obvious linear relation(R^2=0.99). But when the concentration was above 100.96(mg/L),the maximal voltage stably kept around 302mV(the external resistance was 510 Ω).However,the Coulombic efficiency of the short-arm ACMFC gradually increased with the increase of the substrate concentration,from 31.83% to 45.03%.