Preliminary investigation of the influence of pH on the solid-state refuse methanogenic fermentation

Laboratory refuse columns and bottle cultures were used to examine the responses of the interrelated metabolic processes of acid metabolism, solvent metabolism and methanogenesis of the solid-state refuse fermentation to single initial additions of exogenous buffering capacity. Refuse samples poised at neutral and alkaline pH values, by the addition of 0.2 mol/1 phosphate buffer, were found to promote acid-ogenesis to such an extent that methanogenesis was inhibited. The same inhibition was also apparent in the presence of acid pH regimes which were initially characterized by the accumulation of solvents. The possible implications of controlling pH by adding buffer to promote and exploit the refuse fermentation are discussed.