Bio-Electricity generation from industrial wastewater by Microbial Fuel Cell

Abstract

The current study was conducted using a novel approach to develop an up flow anaerobic sludge blanket reactor (UASB) & microbial fuel cell (MFC) together for generating bio-electricity. This technique was used to address the problems that limit upscaling of MFCs along with developing better understanding of waste water treatment. The hybrid technology was used on sugar industry wastewater trying to produce bio-electricity by showing a comparison between 100% wastewater and 80% wastewater and 20% media in order to study the effect of membranes, surface area of electrodes, use of mediators, reactor type which are the limiting factors that control the efficiency of current generation. The micro niches in biofilm oxidizes organic compounds and send electrons to anode and cathode that were made of graphite electrodes having a surface area of 6.67cm2 each. During an intensive review of literature it was seen that Double chamber microbial cell can reduce internal resistance and increase current density as compared to single chamber microbial fuel cell. Therefore, PTFE membrane was selected for developing Double chamber MFC which increased current density and reduced internal resistance. Also studies have shown that electrons are transported more efficiently within few centimeters through biofilm on electrodes, so surface area will be increased by adding electrodes in series in this study 3 electrodes on either sides were used. This provided more area for biofilm development and electron transfer rate was increased. The results achieved by treating 100% sugar industry wastewater giving a maximum of 1.6mA Current generation and OCV value of 7.031mV with an overall COD removal efficiency of 65.5%. ix 10 Whereas, 80% wastewater and 20% media gave a more stable current generation of 0.62 m A and OCV value of 2.114mV with an overall COD removal efficiency of 72.9% The important aspect of this current research based study was to see an overall effect of UASB & MFC in combination to eliminate wastes and treat water for further use enabling it to harness enough bio-electricity and highlight the aspects which are needed to be resolved for future studies that limit the upscaling of this technology to achieve sustainable energy via bio degradable materials.