Biological hydrogen production from mixed waste in a polyurethane foam-sequencing batch reactor

This study investigated the effects of polyurethane foam on continuous hydrogen production from mixed wastes. Molasses was co-fermented with non-pretreated sewage sludge in a sequencing batch reactor. The results indicated that the addition of polyurethane foams as a microbial carrier in the reactor mitigated biomass loss at HRT 12 h, while most of the biomass was washed out during the operation period with no carrier. There was a stable hydrogen production rate of 0.4 L-H₂/l/d in the carrier-sequencing batch reactor. Suspended biomass in the carrier-reactor indicated it possessed the highest specific hydrogen production rate (241 ±4 ml-H₂/g VSS/d) when compared to that of biomass on the surface (133 ± 10 ml-H₂g VSS/d) or inner carrier (95 ± 14 ml-H₂/g VSS/d).