ABSTRACT
Salah satu wilayah yang sangat menjanjikan dengan keberadaan danaunya yaitu Universitas Indonesia. Universitas Indonesia UI memiliki enam danau dengan total luas 269.107 m2 yang sangat penting keberadaannya bagi keseimbangan lingkungan sekitarnya. Saat ini keberadaan danau UI sudah tercemar dengan nilai COD sekitar.

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ABSTRACT
One of the most promising areas with the existence of the lake is Universitas Indonesia. Universitas Indonesia UI has six lakes with a total area of 269,107 m2 which is very important for its existence to balance the surrounding environment. Currently, the existence of UI lake has been contaminated with the COD value of about 1 to 8.000 mg L due to a lot of garbage that enters and buried in it, so that more attention is needed so that pollution will not increase. Microbial Desalination Cell MDC is a development system of Microbial Fuel Cell MFC , which has the ability to desalinate seawater and can produce electricity by using microorganisms as waste decomposers. In addition, MDC method can also reduce the level of waste contained in the substrate used. To improve the performance of MDC, this study utilizes bio charcoal from rice husks to assess the performance of sodium percarbonate in the cathode space with a variation of 0.05 M concentration 0.1 M 0.15 M and 0.2 M, and the performance of the addition of bacterial consortium on the substrate. The best results of this MDC study, in the variation of 0.15 M sodium percarbonate concentration with a decrease of COD and BOD of 93.99 and 83.78 and in variation of addition of bacterial consortium of 1 mL with decrease of COD and BOD 90.04 and 56.52.