Energy valorization of crude glycerol and sanitary sewage in hydrogen generation by biological processes

Abstract

Biohydrogen production was studied with increased concentrations of crude glycerol (CG) co-digested with sanitary sewage by anaerobic consortium bacteria in anaerobic batch reactors, at 30 °C and initial pH 7.0. The CG was obtained during the biodiesel production from waste cooking oils (WCO). The anaerobic consortium was from a granular sludge of UASB reactor used in the treatment of poultry wastes heat treated to inhibit methanogenic activity previously. The higher H2 generation was observed with 240.0 g COD L−1 (35.82 mmol L−1), being consumed 63.9% of CG. The co-digestion associated with sanitary sewage facilitated the CG consumption with the increase of organic load, favoring the acetic acid and 1,3-propanediol production in a liquid phase of the reactors. These results are promising, contributing effectively to the treatment of both wastes with concomitant generation of bioenergy.