The valorization of the anaerobic digestate from the organic fractions of municipal solid waste: Challenges and perspectives.

The anaerobic digestion is a well-established process for the treatment of organic solid waste, pursuing its conversion into a methane rich gas destined to energy generation. Research has largely dealt with the enhancement of the overall bioconversion yields, providing several strategies to maximize the production of bio-methane from the anaerobic processing of a wide variety of substrates. Nevertheless, the valorization of the process effluents should be pursued as well, especially if the anaerobic digestion is regarded in the light of the circular economy principles. Aim of this work is in identifying the state of the art of the strategies to manage the digestate from the anaerobic processing of the organic fractions of municipal solid waste. Conventional approaches are described and novel solutions are figured out in order to highlight their potential scale up as well as to address future research perspectives.