초록
<P><B>Abstract</B></P> <P>In this study, molasses and dark fermentation effluent were solidified using agar and used for H<SUB>2</SUB> production by dark and photo-fermentation. During dark fermentation, the solid jelly form of molasses enabled a slow release of the substrate to the liquid broth hindering fast pH decreases. The initial total sugar concentration, H<SUB>2</SUB> yield, H<SUB>2</SUB> rate and lag phase in dark fermentation were 36.2 g/L, 226.24 mL H<SUB>2</SUB>/g TS, 29.85 mL H<SUB>2</SUB>/h and 4.37 h, respectively. Photo-fermentation of 5.77 g TVFA/L embedded dark fermentation effluent did not lead to efficient H<SUB>2</SUB> production. The best performance in photo-fermentation was obtained with 1.55 g TVFA/L containing diluted dark fermentation effluent. The H<SUB>2</SUB> yield, H<SUB>2</SUB> rate and lag phase in photo-fermentation were 870.26 mL H<SUB>2</SUB>/g TVFA, 0.913 mL H<SUB>2</SUB>/h and 54.07 h, respectively. Embedding concentrated substrate using agar can enhance H<SUB>2</SUB> production performance but only if the release of the substrate does not exceed inhibitory levels and if the rate of diffusion is tolerable for microbial activity.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Molasses and dark fermentation effluent were solidified using agar for H<SUB>2</SUB> production. </LI> <LI> Slow-release of sugar in DF enabled efficient H<SUB>2</SUB> production. </LI> <LI> TVFA release in photo-fermentation from the solid matrix was not convenient. </LI> <LI> Embedding of molasses enabled to start DF with 36.2 g total sugar/L. </LI> <LI> Yields of DF and PF were 226.24 mL H<SUB>2</SUB>/g TS and 870.26 mL H<SUB>2</SUB>/g TVFA, respectively. </LI> </UL> </P>