Biohydrogen Production from Sewage Sludge by Dark Fermentation: The Effects of Adding Inoculum and Heat Pretreatment

The main requirement for efficient H 2 production is the availability of efficient microbial consortia in which H 2 -utilizing and non-H 2 -producing bacteria are suppressed. This study evaluates the H 2 production potentials from sewage sludge with and without pretreated anaerobic culture used as inoculum. Three different anaerobic cultures (mixed anaerobic sludge from CSTR tank reactor, fermented manure, and heat-treated fermented manure) were used as inoculum. Due to hydrolysis during heat treatment, organic matter concentration increased during fermentation. Compared to other operating conditions, heat-treated fermented manure as inoculum and sewage sludge as the substrate mixture had the highest hydrogen production. The results showed that heat pretreatment of inoculum should increase H 2 production potential.