Anaerobic Digesters at WWTPs: factors affecting stability and community composition revealed by time series analyses

Anaerobic digestion (AD) is a successful biotechnology for biogas production at wastewater treatment plants (WWTPs). Time series analyses with high resolution makes it possible to follow dynamics of microbes and investigate factors of importance for the dynamics observed. A large survey was conducted with high-resolution sampling for 3-5 years, covering 5 mesophilic, 2 mesophilic with thermal hydrolysis pre-treatment, and 3 thermophilic digesters located at 10 Danish wastewater treatment plants. This study showed that specific types of digesters had unique microbial communities at species level and each digester had a very constant population of growing dominant species, and fluctuations in the non-growing. Change in temperature from mesophilic to thermophilic showed a clear change in community composition.