Abstract

Dark fermentation hydrogen production from a mixture of food components using two different methods of methanogenic inhibition (autoclaving and BES) and three different temperatures (37, 60, and 70 Â?C) was examined in batch assays for two different mixed anaerobic cultures - one suspended sludge (S) obtained from an anaerobic digester and one granular sludge (G) obtained from a brewery wastewater treatment plant. In general, BES-inhibition of sludge was more robust when compared against heat-treated inoculum. Also, hydrogen, VFA, and sCOD production were affected by increases in temperature although the effects were less severe for G than for S. In addition, differences in individual VFAs were observed between the two inocula.
S produced more acetate as a percentage of VFA_TOTAL compared to G. Conversely, G produced more butyrate compared to S. Differences in the microbial communities were likely responsible for the diverse behaviour of the two inocula.