New operational strategies to overcome technical barriers in anaerobic digestion and extend its fields of application by using meta-omic approaches

The anaerobic digestion of sewage sludge is generally performed under mesophilic (30 – 40 C) or thermophilic (50 – 70 °C) conditions which implies the use of a significant amount of energy input to maintain the performances of the digester. The operation of anaerobic digestion of sewage sludge at low temperatures (between 30 °C and 25 oC) would lead to a reduction of the amount of energy required to heat the bioreactor. Nevertheless, it has also been reported that a decrease in temperature below 30 °C impairs the methane yield of mesophilic digesters, probably because the microbial community structure is affected. To evaluate the effect of temperature on microbial communities, the present study shows the results of the application of low temperature anaerobic digestion at full-scale.