Bioelectricity Generation from Brewery Wastewater in a Dual-Chamber Microbial Fuel Cell: A Repeated Fed-Batch Case Study

The increasing generation of industrial wastewater necessitates sustainable treatment strategies combined with resource recovery. Brewery wastewater, characterized by high organic content and low toxicity, represents a promising substrate for bio-electrochemical systems such as microbial fuel cells (MFCs). This study evaluates the feasibility of electricity generation from wastewater originating from a small-scale research brewery using a dual-chamber glass MFC equipped with a carbon felt anode and a foamed-glass separator. The system was operated in a repeated fed-batch mode over six consecutive 100 h cycles, with fresh wastewater supplied when the cell voltage decreased to 60% of its maximum value. Stable electrochemical performance was observed, with an average cell voltage of 304 mV and a maximum power density of 24 mW·m−2. A consistent decrease in COD concentration of approximately 8.66% per 100 h operational cycle was recorded, along with a 4.93% reduction in NO3− concentration, while NH4+ levels remained largely unchanged. The results indicate that brewery wastewater from small-scale facilities can support sustained bio-electrochemical activity under simplified, non-optimized conditions. Although power output and contaminant concentration changes were limited, the study provides a laboratory-scale study and highlights the need for further optimization of reactor configuration and operational parameters.