초록
Mixing method and hydraulic retention time (HRT) have been shown to affect the photo-fermentation hydrogen production process. In this study, different bioreactors with diverse mixing methods, batch and continuous modes, and a range of HRTs were investigated to determine the optimum operating conditions. The pH value, cell optical density (OD<SUB>660</SUB>), reducing sugar concentration, and cumulative hydrogen yield were monitored during experiments. Experimental results show that magnetic-stirring had negative impacts on hydrogen production due to the OD<SUB>660</SUB> value, substrate conversion efficiency, and cumulative hydrogen yield were all less than half of the static bioreactor. The baffle photo-fermentative bioreactor had the highest hydrogen production rate of 7.37 mmol L<SUP>-1</SUP> h<SUP>-1</SUP>with the highest cumulative hydrogen yield of 512.29 mmol L<SUP>-1</SUP>. Consequently, it was selected as the preferred bioreactor for continuous hydrogen production. In addition, we found the digestion stability increased with an increase in HRT using the baffle photo-fermentative bioreactor. However, the highest cumulative hydrogen yield of 589.21 mmol L<SUP>-1</SUP> and satisfactory substrate conversion efficiency of 40.48% occurred at an HRT of 24 h.