REFUSE ACIDOGENESIS AND METHANOGENESIS - EFFECTS OF FERMENTATION GASES (H2, CO2, CH4)

The effects of selected fermentation gases (H2, CO2, CH4) on refuse acidogenesis and methanogenesis were examined with laboratory batch cultures. Although extremely limited initial stimulation of total methanogenesis resulted from H2 supplementation, both acetogenesis and acetate methanogenesis were inhibited. A culture headspace atmosphere of 100% CO2 effected 98% inhibition of methanogenesis and partial suppression of acetogenesis. A gas mixture of CO2‐CH4 (40: 60) also exerted inhibitory effects on methanogenesis but not acetogenesis. Conversely, 100% CH4 did not significantly reduce methanogenesis or acetogenesis. Individual supplementation with N2 or CO2 in conjunction with increased culture headspace pressure (1.6 bar) approximately doubled the CH4 volumes but volatile fatty acid pattern changes were not apparent. The possible implications of high partial pressures of gas on refuse methanogenesis are discussed. Copyright © 1990, Wiley Blackwell. All rights reserved