Microbial fuel cells (MFC) generate clean energy from organic wastes. This study reports the development and application of novel lab-scale MFC with granular activated carbon-modified electrode fed with synthetic sugarcane vinasse. Biological activity involving nitrogen in the cathode chamber was assessed as a strategy to improve cathode performance under different temperatures (~25, 35 and 55 °C) and external resistance (13 and 300 Ω). High organic matter removal (>90%) was obtained regardless of the condition applied. Nitrification occurred in the cathode chamber at temperature up to 35 °C; this resulted in a decrease in pH to <7, which favored the cathode performance. The anode, applied at 35 °C and 55 °C, presented lower internal resistance and more negative potentials; this shows that the temperature reduced the anode overpotentials. The application of 13 Ω external resistance promoted higher electrogen activity, which resulted in coulombic efficiency up to 12.6 ± 2.4% against 1.9 ± 0.2% at 300 Ω. The combination of the proposed configuration, operation and electrode materials yielded maximum power density of 41.3 W m⁻³, which is higher than values reported by other studies with similar electrode materials, reactor configuration (not stacked) and substrate composition (diversified). The findings contribute to the development of scalable renewable energy generation systems based on combination of biochemical and bioelectrochemical processes in wastewater treatment.

微生物燃料电池（MFC）从有机废物中产生清洁能源。这项研究报告了新型的实验室规模的MFC的发展和应用，该MFC具有由合成的甘蔗酒糟喂养的颗粒状活性炭改性电极。作为在不同温度（〜25、35和55°C）和外部电阻（13和300Ω）下改善阴极性能的一种策略，评估了在阴极室中涉及氮气的生物活性。无论采用何种条件，都能获得较高的有机物去除率（> 90％）。在高达35°C的温度下在阴极室中发生硝化；这导致pH值降低至<7，这有利于阴极性能。在35°C和55°C的条件下施加的阳极呈现出较低的内部电阻和更多的负电势。这表明温度降低了阳极过电势。13Ω的外部电阻的施加促进了更高的电子活性，从而导致库仑效率高达300Ω时的1.9±0.2％达12.6±2.4％。所建议的配置，操作和电极材料的组合产生的最大功率密度为41.3 W m^-3，高于其他研究报告的类似电极材料，电抗器配置（未堆叠）和基板组成（多样化）的值。这些发现有助于废水处理中基于生化和生物电化学过程相结合的可扩展可再生能源发电系统的开发。