Valorization of solid waste biomass by inoculation for the enhanced yield of biogas

The current work reports experimental outcomes about anaerobic digestion (AD) of the organic fraction of catering solid waste to produce biogas and methane yield and solidity of the entire system. The possibility of developing AD as an efficient technique for food waste management has also been considered. Inoculation is an established technique to enhance biogas yield through digested sludge, rumen fluid, and slurry recirculation; although this method is proven on cattle manure, however, it is not well studied on food waste. The current study investigates the use of animal intestinal waste as inoculums to enhance biogas yield of food waste. The findings are benchmarked with cattle manure employing known digester materials of carbon steel, aluminum alloy, and at anaerobic mesophilic conditions. The inoculation was varied up to 30% by mass of the substrate materials in each case. The research finds that food waste inoculation was up to 30% using carbon steel reactor under mesophilic temperature conditions (30 ± 1 °C). The food waste produced biogas at a faster rate with a higher yield compared to cattle manure in all digester materials. The biogas yield kept increasing with increasing inoculum ratio reaching optimal at 30% in the case of both food waste and cattle manure with all the digester materials. Graphic abstract