*7.4. Salinity*

Although approximately 5% of the earth's wastewaters are extremely saline, MFC may be more helpful in treating these wastewaters. Increased salinity improves power generation through increased conductivity. Increased conductivity promotes proton transport and therefore reduces the system's internal resistance. Lefebvre et al. demonstrated that adding up to 20 g/L of NaCl improved the cumulative efficiency of MFCs by decreasing internal resistance by 33% and boosting maximum power output by 30% [154].
