Microbial fuel cells (MFCs) are considered as 1 of the main sources of renewable energy. Besides, as a novel kind of these systems, sediment microbial fuel cells (SMFCs) turned many eyes into their effective application in power generation. Applying SMFCs in areas where nutrient-rich precipitates are used to grow microorganisms has been studied for several times over the last few years. One way to produce renewable and nondestructive energy is the usage of energy found in biomass resources which is proved by MFC technology and all types of it such as SMFCs. In this research, conductive metal brushes with high effective surface were evaluated as cathode electrode in the system. Also, we have investigated the effect of different kinds of sediments in power generation of SMFC. At the beginning, 4 different ecosystems (sea and 3 different areas of the river at a distance of 200, 300, and 400 m far from the sea) were evaluated to assess their potential for electricity generation. In comparison to other ecosystems, river sediment generates the highest power density of about 121 mu W/cm(2). As well, the influence of catholyte conductivity increment was analyzed with economic salt (NaCl). By this, it was concluded that the output power increases while catholyte conductivity increase. To determine the depth of the cathode between the sediment and water surface, the electrode was placed in 3 different distances of about 0.5, 3, and 6 cm. The results demonstrated that the electrode with less distance from the sediment surface could produce more power and current density.