Thermophilic anaerobic digestion for sewage sludge stabilization

The microbially mediated biochemical reactions that occur during anaerobic digestion processes for methane production from soluble carbon energy substrates are well known, but in spite of this, the interactions within the multi-species cultures responsible for the overall process require more detailed elucidation. When the process feed comprises mixed, solid, carbon energy substrates, as in the case of waste sewage sludge stabilization, many aspects of both the process biochemistry and microbiology are unresolved. This mini-review seeks to identify some of these unresolved questions, particularly with respect to operation at thermophilic temperatures.