The final stage of methanogenesis produces methane by two
groups of methanogenic bacteria: the first group splits acetate into
methane and carbon dioxide and the second group uses hydrogen as
electron donor and carbon dioxide as acceptor to produce methane.
2.2. Affecting parameters
Within the anaerobic environment, various important parameters
affect the rates of the different steps of the digestion
process, i.e. pH and alkalinity, temperature, and retention times.
2.2.1. pH, alkalinity and volatile acids/alkalinity ratio
Each group of micro-organisms has a different optimum pH
range. Methanogenic bacteria are extremely sensitive to pH with