Find in Library

In this study, the addition of bentonite at different proportions as clay minerals and various thicknesses (4, 5, and 6 mm) of ceramic membranes were evaluated for proton and oxygen mass transfer coefficients. Bentonite (20% and 4 mm) was found to be optimum and was then employed to assess earthen microbial fuel cell (EMFC) performance for different substrates (kitchen waste (KW) slurry and leachate) under batch mode. Both substrates were added in different concentrations of chemical oxygen demand (COD), i.e., 18, 15.2, 12.5, 9.7, and 6.9 g/L to EMFCs. The EMFC achieved superior organic removals for leachate (>96%). Intriguingly, the volatile fatty acids (VFAs) generation and consumption were different for each substrate. Each system expressed affinity towards acetic acid, but limited VFAs (acetic and propionic) were generated by KW while leachate generated acetic, propionic, and butyric. The leachate concentration having COD of 15.2 g/L produced the highest power density of 586.5 ± 38.8 mW/m3, while for KW, only 41.5 mW/m3 (6.9 g/L of COD for KW) was obtained. The study consolidates the need for an intermediate step to pre-treat the organic fraction of waste before its use for resource recovery. Bentonite was found as an effective clay mineral for manufacturing ceramic membranes. HIGHLIGHTS Bentonite (20%) at 4 mm thickness was found optimum for ceramic membrane.; Organic removal was superior for leachate (>96%) than kitchen waste (KW).; Highest PD of 586.5 ± 38.8 mW/m3 for leachate (LW-4) and 41.5 mW/m3 for KW (KW-1).; Resistance increased with KW concentration while decreased for leachate.; Substrate inhibition and limitation show importance of substrate strength and type.;