Acclimatization of methanogen consortium capable to digest relevant percentages of municipal solid waste in codigestion with cattle manure

The acclimatization of an anaerobic consortium capable of producing methane through the co-digestion of municipal solid waste (MSW) and cattle manure was achieved through a fed batch procedure1. Anaerobic microcosms consisting of 46 mL of pre-treated MSW were set up under strictly anaerobic conditions and statically incubated at 35°C. MSW volatile solids (VS) were from 60 to 100% of the mixture applied. Four successive 1-month batch experiments were performed by leaving 10% (v/v) of the digested sludge in the bottles and refilling them with the corresponding fresh cattle manure amended MSW. Biogas production and composition as well as VS, volatile fatty acids and electron acceptors occurring in the microcosms were investigated together with the structure and composition (via DGGE analysis) of microbial population responsible for the MSW digestion. Biogas and CH4 production increased significantly from the 1st to 4th batch experiment, especially where higher amounts of cattle manure were applied (i.e., about 160 mlCH4/gVS, representing the 41% of the total biogas produced, by digesting MSW with 60% of total VS). 1. Bertin, L.; Todaro, D.; Bettini, C.; Fava, F. Wat. Sci. Technol. 2008, 58(9), 1735-1742.