Yoshida Naoko, Miyata Yasushi, Iida Kazuki
Department of Civil Engineering, Nagoya Institute of Technology Nagoya Aichi Japan
Nagoya Municipal Industrial Research Institute 3-4-41, Rokuban, Atsuta-ku Nagoya 456-0058 Japan.
RSC Adv. 2019 Nov 29;9(67):39348-39354. doi: 10.1039/c9ra07671a. eCollection 2019 Nov 27.
The oxidation of a carbon anode has been reported to enhance electricity recovery in a microbial fuel cell (MFC). This study investigates the applicability of electrochemically oxidized graphite felt (EOGF) as the anode for the recovery of electricity from sewage wastewater when polarized at 0.2 V during MFC operation. EOGFs were prepared by polarizing graphite felt (GF) at 2 V in 1% sulfuric acid or nitric acid. The nitric acid-treated EOGF inoculated with an sewage sludge produced a maximum current of 110 μA cm, which exceeds that produced by the original GF (91 μA cm) under electrochemical cultivation at 0.2 V Ag/AgCl. This outcome is attributed to a decrease in charge-transfer resistance and an increase in the capacitance of the anode. In contrast, electrochemical oxidation did not affect the chemical oxygen demand (COD) removal rate or the microbial community structure of the anode. The MFC equipped with the EOGF delivered 340-560 mW m-MFC of electricity during operation in the drainage water channel of a primary sedimentation tank, which corresponds to 11-15 μA cm of current density. The lower current produced in the MFC compared to that observed during electrochemical cultivation indicates that factors other than the anode material restrict current production in the MFC. Even with the small amount of generated electricity, when operated for more than three days, the MFC provides a positive net energy balance when integrated with post-aeration treatment.
据报道，碳阳极的氧化可提高微生物燃料电池（MFC）中的电力回收。本研究调查了电化学氧化石墨毡（EOGF）作为阳极在MFC运行过程中于0.2 V极化时从污水中回收电力的适用性。EOGF通过在1%硫酸或硝酸中于2 V极化石墨毡（GF）制备。接种了污水污泥的经硝酸处理的EOGF产生的最大电流为110 μA/cm²，超过了在0.2 V Ag/AgCl电化学培养条件下原始GF产生的电流（91 μA/cm²）。这一结果归因于电荷转移电阻的降低和阳极电容的增加。相比之下，电化学氧化并未影响阳极的化学需氧量（COD）去除率或微生物群落结构。配备EOGF的MFC在初沉池排水渠道运行期间提供了340 - 560 mW/m²-MFC的电力，这对应于11 - 15 μA/cm²的电流密度。MFC中产生的电流低于电化学培养期间观察到的电流，这表明除阳极材料外的其他因素限制了MFC中的电流产生。即使产生的电量很少，但当运行超过三天时，与曝气后处理相结合的MFC提供了正的净能量平衡。
