Microalgae cultivation in ammonia rich digestate subjected to different pretreatment stages

Anaerobic digestion has been beneficial for the energy valorization of a broad variety of residues. However, the effluent from the digesters, the digestate, usually has high ammonia nitrogen, requiring additional measures for its management. Photosynthetic microalgae assimilate nitrogen, and can be used for the treatment of digestate, while grown biomass can be valorized in the formation of added value products. The aim of this work was the examination of the efficiency of Chlorella sorokiniana for the treatment of various digestate samples subjected to subsequent treatment stages. Results showed that Chlorella can efficiently be used in digestate, although high ammonia content may inhibit growth. Cells composition depends on operation conditions as well as on substrate properties.