Addressing the environmental risks posed by the persistence of penoxsulam, a widely used herbicide, microbial fuel cells (MFCs) offer a promising bioelectrochemical approach for simultaneous pollutant degradation and energy recovery. This study aimed to optimize a single-chamber air-cathode MFC for efficient penoxsulam degradation coupled with electricity generation. Key operational parameters were systematically investigated, including electrogenic bacteria (Shewanella putrefaciens, Shewanella oneidensis MR-1, mixed culture), cathode diffusion layer structure (2–8 PTFE layers), anode material (carbon cloth, carbon felt, graphite felt), initial penoxsulam concentration (1–20 mg/L), and initial anolyte pH (5.0–9.0). Results indicated that S. putrefaciens significantly outperformed other strains, achieving 62.7% degradation of 10 mg/L penoxsulam. Optimal configuration involved a four-layer PTFE cathode diffusion layer, providing stable operation (>240 h) and a maximum power density (Pmax) of 58.6 mW/m2, and a graphite felt anode, which exhibited the highest double-layer capacitance (0.0026 mF) and supported the greatest biofilm attachment. Penoxsulam degradation efficiency reached 97.2% at a low initial concentration (1 mg/L), which also yielded the highest Pmax (77.2 mW/m2), whereas higher concentrations inhibited both degradation and power output. Neutral to slightly alkaline conditions (pH 7.0–8.0) were optimal, maximizing power density (62.4 mW/m2 at pH 8.0) and degradation rate (62.7% at pH 7.0). This study demonstrates the feasibility of optimized single-chamber MFCs for effective penoxsulam bioremediation and electricity generation, highlighting the critical influence of microbial selection, electrode design, substrate concentration, and pH.
He et al. (Sun,) studied this question.