Pre-composting of municipal solid wastes as enhancer of bio-hydrogen production through dark fermentation process

Abstract

This study was focused on bio-hydrogen production from thermophilic dry anaerobic acidogenic co-digestion (55 °C and 20 % of total solids) of pre-composted mixtures of organic fraction of municipal solid waste (OFMSW) and food waste (FW). Three different mixture ratios of OFMSW:FW (80:20, 70:30 and 50:50) have been tested. The application of pre-composting improved the hydrolytic and acidogenic phases in the subsequent acidogenic co-digestion, reaching an increase in the bio-hydrogen production in the range of 45.4–46.7 %. In this sense, the best results were obtained for the pretreated mixture with the ratio 70:30, with 42.9 LH2/kg VSadded and 53.9 % of H2 in the biogas. Finally, the kinetic study has corroborated that pre-composting clearly enhances the kinetics of acidogenic fermentation of OFMSW and FW mixtures. In fact, the μmax and YP values for the pretreated mixtures have been increased by a 20 % and 33 % respectively.