Saline catholytes as alternatives to phosphate buffers in microbial fuel cells

► High salinity solution used instead of phosphate buffer in two-chamber MFCs. ► Maximum power of 491 mW/m2 was only 17% less than from MFCs with 50 mM PBS. ► The air-cathode was kept relatively free of a biofilm and CE was increased. ► Current production was reduced slightly due to pH changes.