Eliminating methanogenic activity in hydrogen reactor to improve biogas production in a two-stage anaerobic digestion process co-digesting municipal food waste and sewage sludge

► A two-stage AD model fed with a mixture of municipal FW and sewage sludge was operated for about 280 days. ► Key variables: treatment methods of feedstock and the mixed liquid in H2 reactor. ► Key findings: both feedstock and the mixed liquid need treatment to get significant H2 production. ► CH4 production in second stage was improved by H2 production in first stage by a factor of 2-fold. ► CH4 production was also evaluated by BMP test using feedstock and H2 reactor effluent as substrate.