ENHANCED HYBRID SYSTEM OF MEC-AD THROUGH MODIFIED ELECTRODES WITH MULTI-WALL CARBON NANOTUBES

Abstract

 The hybrid system of microbial electrolysis cell (MEC) and anaerobic digester (AD) has been a promising approach for sustainable energy production and waste treatment. The integration of MEC and into the AD digester offers multiple advantages over conventional AD systems. The study was conducted on the modification of carbon felt (CF) anode, and stainless-steel mesh (SSTM) cathode with multi-wall carbon nanotubes (MWCNT), to facilitate the biomethane production and upgrade within the hybrid system. The microbial attachment to the electrodes was analyzed, the substrate concentration, current density, and biogas composition and volume were monitored. The SEM imaging of the electrodes showed that the microbes followed a different growth behaviour in modified and unmodified electrodes. In addition, MWCNT modified SSTM showed a potential hydrogenotrophic growth selectivity, unlike unmodified SSTM, which had a more syntrophic microbial community. Stainless steel mesh-modified cathode showed the highest biogas and methane production with a value of 14.4 ml CH₄/g glucose. In addition, the carbon-felt modified electrodes showed a maximum substrate degradation value of 93% and a current density of 4.5 mA/m².