Innovative bioelectrochemical-anaerobic-digestion coupled system for ammonia recovery and energy production from ammonia-rich residues

Inhibition of anaerobic digestion process by high levels of ammonia (NH4+/NH3) is the most serious problem existing in Danish biogas plants. No viable/applicable method to overcome this problem has been found up to now. This project proposes an innovative process which integrates bioelectrochemical system (BES) with anaerobic digestion to recover ammonia, and thereby enhance biomethanation of ammonia-rich residues. In this process, ammonia recovery and electricity production will be realized in a novel BES submersed in an anaerobic reactor. Moreover, removal of ammonia from anaerobic reactor will alleviate or counteract ammonia inhibition and enhance the conversion of ammonia-rich wastes to biogas, giving synergistic advantages for both ammonia recycling and increase of biogas production. The system performance and potential limitations will be addressed and technical solutions will be developed.