1.College of Environmental Science and Engineering,Hebei University of Science and Technology,Hebei;2.Hebei Institute of Geological Environment Monitoring,Key Laboratory of Geological Resources and Environment Monitoring and Protection of Hebei Province
微生物燃料电池(MFC)在处理含硝酸盐(NO3--N)废水时具有同时产电和脱氮的潜力,寻找成本低且改善其产电脱氮性能的阴极修饰材料是MFC在含氮废水处理领域应用的关键。氧化亚铜/还原氧化石墨烯(Cu2O/rGO)复合材料具有良好的电化学性能,在替代铂基材料提高MFC性能方面具有一定的应用前景。本研究通过还原法制备了Cu2O/rGO复合材料,并对材料的结构和氧还原性能进行表征；同时,将其负载于阴极碳布后分析其电化学性能,并通过MFC的输出电压、功率密度和NO3--N的去除率探究Cu2O/rGO阴极对MFC产电和脱氮性能的强化作用；通过对反硝化相关酶活性和胞外聚合物的测定,探究Cu2O/rGO阴极强化MFC性能的机理。结果表明：Cu2O/rGO复合材料具有大量的介孔结构,能够为电子传递提供更多的通道,并且Cu2O/rGO复合材料具有良好的氧化还原可逆性；与Pt/C阴极相比,Cu2O/rGO阴极的交换电流密度升高33.53%,电子转移阻力降低65.53%；Cu2O/rGO-MFC在处理NO3-N废水时获得的最大平均输出电压(662.54 mV)、最大功率密度(26.27 mW/cm2)、平均库伦效率(32.02%)和NO3--N去除速率(83.33 mg NO3--N L/h)均高于Pt/C-MFC(485.33 mV,16.98 mW/cm2,7.38%,41.67 mg NO3--N L/h)；Cu2O/rGO复合材料通过提高MFC阴极反硝化关键酶活性和类蛋白组分含量,改善了MFC的产电和脱氮性能。
Microbial fuel cells (MFC) have the potential of generating electricity and removing nitrogen simultaneously in the treatment of nitrate containing wastewater. It is crucial to find a cathode modified material with low cost and improved performance of generating electricity and removing nitrogen for the commercial application of MFC in the field of wastewater treatment. Cuprous oxide/reduced graphene oxide (Cu2O/rGO) composite which has the advantages of excellent electrochemical properties, hold a wide application prospect in replace of Pt-based material for improving performance of microbial fuel cells (MFCs). In this study, material characterization and oxygen reduction property were conducted to analyze the synthesis of Cu2O/rGO composite materials after synthesis by reduction method. The electrochemical performance of Cu2O/rGO cathode was analyzed after it was loaded on the surface of cathode carbon cloth. The enhancement effect of Cu2O/rGO cathode on the power generation and nitrogen removal performance of MFC were investigated through the output voltage, power density and NO3--N removal rate of MFC. The mechanism of Cu2O/rGO cathode enhancing MFC performance was investigated by measuring denitrifying enzyme activity and extracellular polymer. Results showed that Cu2O/rGO which has a large number of mesoporous structures, provide more channels for electron transport, and Cu2O/rGO has better redox reversibility. Compared with Pt/C cathode, the exchange current density of Cu2O/rGO cathode increases by 33.53%, the electron transfer resistance decreases by 65.53%. The maximum average output voltage (662.54 mV), maximum power density (26.27 mW/cm2), NO3--N removal rate (83.33 mg NO3--N L/h) and average coulomb efficiency (32.02%) of Cu2O/rGO-MFC were higher than those of Pt/C-MFC (485.33 mV, 16.98 mW/cm2, 7.38%, 41.67 mg NO3--N L/h). Cu2O/rGO composite material enhance the activity of key enzymes and the content of protein-like components in denitrification of MFC cathode, improving the performance of electricity generation and nitrogen removal of Cu2O/rGO-MFC.