Microbial fuel cell – A novel self-powered wastewater electrolyser for electrocoagulation of heavy metals

This paper describes the suitability of the Microbial Fuel Cell (MFC) for generation of electrical power with a simultaneous synthesis of active catholyte in the form of caustic solution. The active solution formed inside a terracotta based MFC reactor was a product of self-powered wastewater electrolysis utilizing i) wastewater with added sodium acetate as a carbon source and ii) neat urine. The catholyte solution that has been actively synthesized was harvested and used for precipitation of heavy metals such as: iron, copper and zinc showing its suitability for use in electro-coagulation (electro-flocculation). This proposed alternative approach to self-powered electrocoagulation is based on electrochemically formed caustic catholyte within the inner cathode chamber of the MFC and then used ex situ to form metal hydroxides that precipitate out from heavy metal solutions.