Effects of electrolyte conductivity on power generation in bio-electrochemical systems

Bio-electrochemical systems (BESs) have recently attracted considerable attention as a promising technology for sustainable wastewater treatment. However, the practical applications of BESs remain limited partly because the conductivity of actual wastewater can vary from 0.2 to 40 ms/cm which is out of the appropriate range for power generation. Herein, we investigated the effect of anolyte and catholyte conductivities on power generation. The maximum current density (0.73 mA/cm 2 ) was achieved by reactors using an anolyte solution with a conductivity of 14.93 ± 0.02 ms/cm; this was four times higher than the minimum current density (0.13 mA/cm 2 ), obtained using a solution with a conductivity of 2.61 ± 0.04 ms/cm. Anolyte conductivity was found to be the primary rate-limiting factor for power generation and had a greater effect than the conductivity of the catholyte. Furthermore, an anolyte conductivity range of 6.45–14.93 ms/cm was found to be most appropriate for superior BES performance.