초록
<P><B>Abstract</B></P> <P>In this study, the performance of a new cell immobilization material, namely ceramic ball, was examined for continuous biohydrogen production in comparison to suspended cell culture system (CSTR). Production of biohydrogen in both systems was assessed under thermophilic conditions. Both systems were operated at varying hydraulic retention times (HRT) by shortening HRT values from 24 to 1.5 h at an influent sucrose concentration of 10 g/l. The immobilized bioreactor configuration outcompeted the CSTR bioreactor in terms of both volumetric hydrogen production (2.7 l H<SUB>2</SUB>/l/day for immobilized system @ HRT = 3 h and 0.5 l H<SUB>2</SUB>/l/day for CSTR @ HRT = 24 h) and resistance to cell-washout (CSTR reactor lost significant amount of biomass at short HRT values). It was concluded that immobilized bioreactor configuration is much more robust than CSTR against high organic loading rates and 5 fold more volumetric hydrogen production was achieved in 8 fold smaller immobilized bioreactor.</P> <P><B>Highlights</B></P> <P>► Biohydrogen production by immobilized and suspended bioreactors were compared. ► Ceramic balls (450 m<SUP>2</SUP>/L) were used as support matrix for the first time. ► Stable biohydrogen production was achieved even at low HRTs in immobilized reactors. ► 5 folds more hydrogen production was achieved in 8 times smaller bioreactor.</P>