Analysis of Degradable Household Kitchen Waste and Harnessing Bioelectricity from it by Enhoncing Microbial Fulr cell ( MFC) Performance

Abstract

Today the world is facing a problem in solid waste management along with global energy depletion due to rapidly increasing population. Microbial Fuel Cell (MFC) technology, which transforms chemical energy residing in organic compound into electrical energy with the support of microbes, is regarded a promising alternative. In this study, dual chambered Microbial Fuel Cell (MFC) was operated to evaluate the potential for degradation of organic kitchen waste under anaerobic microenvironment using mixed consortia as anodic biocatalyst. The potential for bioelectricity generation from this system was also evaluated. Degradation potential of waste was evaluated by observing Chemical Oxygen Demand (COD), Ammoniacal-nitrogen and Phosphorus removal rates. Initially, the degradable kitchen waste had COD content of 26.75 ± 0.68 mg/g, Ammoniacal-nitrogen 0.017 ± 0.005 mg/g and Phosphorus 0.0956 ± 0.0068 mg/g. When multi-walled carbon nanotubes (MWCNT) coated graphite sheet electrode was used as anode, graphite sheet as cathode, organic kitchen waste as anolyte and phosphate buffer along with KMnO4 as electron acceptor there was reduction in COD by 41.53 %, Ammoniacal-nitrogen by 64.12 % and Phosphorus by 45.25 %. Sugar analysis in waste sample was done by HPLC. The amount of glucose was 167.39 ± 10.21 mg/g and arabinose was 11.22 ± 0.69 mg/g. These sugars were not detected during end product analysis by HPLC which means we can say there was complete removal of these sugars. The maximum OCV observed was 558.0 ± 25.23 mV when multi-walled carbon nanotubes (MWCNT) coated graphite sheet electrode was used as anode electrode. Maximum power density of 323.59 ± 33.89 W/m 3 was obtained when an external resistance of 1000 ohm was used. The Microbial Fuel Cell (MFC) electrical performance was examined with cyclic voltammetry (CV). Bacteria from anode biofilm were isolated. Their morphological, biochemical and molecular characterization up to PCR were performed and submitted for sequence analysis. Biocompatibility test was performed to observe if the coated MWCNTs and neutral red had negative effect on anode biofilm. Resistance of the isolates to multiple drugs suggested proper management and disposal of domestic waste. End products analysis after MFC performance was done by using HPLC and concentration of each compounds were determined. Finally, this research conveys that microbial fuel cell (MFC) can be a promising alternative for organic waste management along with electricity generation. Keywords: organic kitchen waste, Microbial Fuel Cell (MFC), Chemical Oxygen Demand (COD), Multi-walled Carbon Nanotubes (MWCNTs), Cyclic Voltammetry (CV), High Performance Liquid Chromatography (HPLC)