초록
<P><B>Abstract</B></P> <P>The co-fermentation of vinasse and cheese whey (CW) was evaluated in this study by using two thermophilic (55° C) anaerobic fluidized bed reactors (AFBRs). In AFBR using vinasse and CW (AFBR-V-CW), the CW was added in increasing proportions (2, 4, 6, 8, and 10 g COD.L<SUP>−1</SUP>) to vinasse (10 g COD.L<SUP>−1</SUP>) to assess the advantage of adding CW to vinasse. By decreasing the hydraulic retention time (HRT) from 8 h to 1 h in AFBR-V, maximum hydrogen yield (HY), production rate (HPR), and H<SUB>2</SUB> content (H<SUB>2</SUB>%) of 1.01 ± 0.06 mmol H<SUB>2</SUB>.g COD<SUP>−1</SUP>, 2.54 ± 0.39 L H<SUB>2</SUB>.d<SUP>−1</SUP>.L<SUP>−1</SUP>, and 47.3 ± 2.9%, respectively, were observed at an HRT of 6 h. The increase in CW concentration to values over 2 g COD.L<SUP>−1</SUP> in AFBR-V-CW decreased the HY, PVH, and H<SUB>2</SUB>%, with observed maximum values of 0.82 ± 0.07 mmol H<SUB>2</SUB>.g COD<SUP>−1</SUP>, 1.41 ± 0.24 L H<SUB>2</SUB>.d<SUP>−1</SUP>.L<SUP>−1</SUP>, and 55.5 ± 3.7%, respectively, at an HRT of 8 h. The comparison of AFBR-V-CW and AFBR-V showed that the co-fermentation of vinasse with 2 g COD.L<SUP>−1</SUP> of CW increased the HPR, H<SUB>2</SUB>%, and HY by 117%, 68%, and 82%, respectively.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Addition of cheese whey (2 g COD.L<SUP>−1</SUP>) to vinasse increased H<SUB>2</SUB> yield (HY) by 82%. </LI> <LI> Excess cheese whey concentration decreased HY by lack of nitrogen. </LI> <LI> Decrease in hydraulic retention time (HRT < 6 h) decreased HY and production rate (HPR). </LI> <LI> Maximum HY (1.01 ± 0.06 mmol H<SUB>2</SUB>.g COD<SUP>−1</SUP>) was observed in HRT of 6 h. </LI> <LI> H<SUB>2</SUB> production in both reactors was dominated by acetic and butyric pathways. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>