Small-scale microbial fuel cells utilising uric salts

• Uric salts were tested for the first time as fuel for electricity generation in MFCs.
• When uric salts were added to other substrates, power generation and longevity improved.
• Small-scale MFCs produced a comparable amount of power output to that produced by larger MFCs.

With exhausting fossil fuels and increasing greenhouse gas emissions, numerous attempts, to overcome future energy challenges, are being pursued. In this study, small-scale microbial fuel cells (MFCs, 0.7 mL anodic chamber volume) were built to investigate their electrical performance with uric salts as fuel for power generation. When uric salts were added to other substrates such as urine or sewage sludge, results showed improved power generation and longevity. The small-scale MFCs produced a comparable amount of power output (PMAX: 11.09 mW/m2; 44.36 W/m3) to that produced by larger MFCs, which suggests that MFC miniaturisation and multiplication is a sound approach for scale-up and practical implementation.