Conventional wastewater treatment plants generally use an anaerobic digester to stabilize the wastewater settleable solids and the excess microbial solids produced within the plant. The anaerobic fermentation process is very pH dependent. The methane bacteria which are responsible for the final step in the anaerobic fermentation process and are probably responsible for most operational problems as they are considered to be very pH sensitive. Because of this sensitivity, the pH tolerance of the acetate fermenting methane bacteria was investigated using laboratory anaerobic filters. The research involved the following studies: determining what relative rate of methane production can be achieved at various pH levels, determining the effect of the non-optimum pH duration on the fermentation rate, and determining what fermentation recovery time can be expected from non-optimum pH levels and what effect the non-optimum pH duration has on this recovery.

Includes bibliographical references (pages 134-141). Microfiche.