Transition of mesophilic anaerobic digesters to thermophilic conditions
Research Project , 2019 – 2020

Anaerobic digestion of sewage sludge and organic waste is an important process to minimize the waste mass and
produce energy-rich biogas. Increasing the temperature from mesophilic (35°C) to thermophilic (55°C) conditions is a
method to increase the biogas yield and kill pathogens. However, the microorganisms that carry out degradation of
organic matter are different in mesophilic and thermophilic conditions and the shift in microbial community that occurs
when the temperature is increased can lead to unstable operation or process failure. The best strategy for converting
mesophilic digesters to thermophilic conditions is unknown.
The goal of this study is to clarify how different conversion strategies affect the microbial communities in anaerobic
digesters. We will analyze samples collected during a pilot-scale experiment carried out at Rya wastewater treatment
plant in Gothenburg. Six reactors were operated in parallel, three were converted to thermophilic conditions and three
served as mesophilic controls. The measurements and samples collected during the experiment form a unique set of
data with high practical relevance because of the similarity to full-scale conditions. We will use high-throughput DNA
sequencing to examine changes in the microbial community during the temperature increase.

Participants

Oskar Modin (contact)

Professor at Chalmers, Architecture and Civil Engineering, Water Environment Technology

Frank Persson

Associate Professor at Chalmers, Architecture and Civil Engineering, Water Environment Technology

Britt-Marie Wilen

Professor at Chalmers, Architecture and Civil Engineering, Water Environment Technology

Collaborations

Gryaab AB

Gothenburg, Sweden

Funding

Stiftelsen Längmanska kulturfonden

Funding Chalmers participation during 2019–2020

J. Gust. Richert stiftelse

Funding Chalmers participation during 2019–2020

Gryaab

Funding Chalmers participation during 2019–2020

Related Areas of Advance and Infrastructure

Sustainable development

Driving Forces

Energy

Areas of Advance

C3SE (Chalmers Centre for Computational Science and Engineering)

Infrastructure

More information

Latest update

2020-04-27