One way to treat oil waste is a seawater desalination system that uses exoelectorgenic bacteria as an agent for the degradation of organic compounds contained in oil waste. Microbial Desalination Cell (MDC) is a development of Microbial Fuel Cell (MFC), a method that can eliminate salt content in seawater using electricity generated by bacteria from wastewater. Stacked Microbial Desalination Cell (SMDC) is an MDC development where SMDC uses many pairs of ion Exchange Membranes (IEMs) where IEMs are placed between the Anion Exchange Membrane (AEM) and the Cation Exchange Membrane (CEM). This is intended to increase the efficiency of electron transfer. SMDC can also return more energy than other types of MDC so that the cost is more effectively. In this research, using a 2-SMDC reactor configuration with graphite rods as anode, CFC coated with activated carbon as a cathode, potassium permanganate as catholyte, and adding ion exchange resin to salt chamber. Independent variables used in this research were activated carbon mass variations of 0, 2, and 4 g. Parameters that will be obtained are COD, electrical productivity, and pH. The results obtained in this study indicate that the optimum mass variation of activated carbon is 4 g by adding Ion Exchange resin (ratio Resin Na and Cl 1: 1) with a COD reduction of 57.808% and produces electrical productivity of 0.000561 W/m3, and the change in pH by 0.24.