Perspective on anaerobic digestion for biomethanation in cold environments

The anaerobic digestion (AD) has become an important part of the wastewater treatment plants that regulates the sustainable management of organic wastes with simultaneous production of bioenergy. AD at low temperatures using psychrophilic anaerobes with optimum growth temperatures < 20 degrees C has gained significant attention for improvement of biogas productivity in cold regions. The present review discusses the detailed characteristics of psychrophilic anaerobes, and how the properties of those particular psychrophiles can be utilized towards the cost-effective production of methane at cold environment. The different challenges for AD at low temperature have been described thoroughly. The various strategies such as (a) adaptation of microbial community, (b) optimization of operational parameters, (c) utilization of specialized biodigester design, and (d) modification of downstream process to improve the AD and biomethane production in cold environments have also been summarized. The present review proposes the future technological developments which should be aimed at effective performance of anaerobic digesters to improve biomethanation in cold regions.