EFFECTS OF CARBON-DIOXIDE AND METHANE ON METHANOGENESIS

A mixed microbial culture, enriched from sewage sludge, was cultivated on a glucose medium in a high turbulence fermentor at constant temperature, pH and loading rate. Effects of high pCO2 (0.95 atm) and pCH4 (0.90 atm) were compared to those of low pCO2 (0.05 atm) and pCH4 (0.05 atm). Generally, rapid in creases in pCO2 resulted in rapid decreases in methane production and, conversely rapid decreases in pCO2 by N2-sparging resulted in rapid increases in methane production. Decreased values of methane production were also accompanied by acetic acid accumulation. No inhibiting effects of high pCH4 were detected. A method to obtain low pCO2 by gas recycling combined with CO2-absorption is proposed. © 1979 Springer-Verlag.