초록
<P><B>Abstract</B></P> <P>Effects of biochar (BC) and ferrous iron (Fe<SUP>2+</SUP>) additions on hydrogen (H<SUB>2</SUB>) production from glucose were investigated using batch experiment. The glucose with both BC and Fe<SUP>2+</SUP> additions were incubated at 37°C for H<SUB>2</SUB> production. As compared with the control group (without BC and Fe<SUP>2+</SUP> additions), the synergic effects of BC and Fe<SUP>2+</SUP> make the lag phase time decease from 4.25 to 2.12h, and H<SUB>2</SUB> yield increase from 158.0 to 234.4ml/g glucose. Moreover, suitable concentrations of BC and Fe<SUP>2+</SUP> serve to enhance volatile fatty acid generation during H<SUB>2</SUB> evolution. These results indicate that H<SUB>2</SUB> production is improved by BC and Fe<SUP>2+</SUP> regulations, where synergic mechanisms are described as follows: BC acts as support carriers of anaerobes and system pH buffers, which promotes the biofilm formation and maintains suitable pH environment; Appropriate Fe<SUP>2+</SUP> concentration can improve hydrogenase activity in H<SUB>2</SUB> production.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Suitable ferrous iron (Fe<SUP>2+</SUP>) could improve [Fe-Fe]-hydrogenase activity. </LI> <LI> Biochar (BC) addition could facilitate hydrogen-producing bacteria growth. </LI> <LI> Maximum H<SUB>2</SUB> yield of 234.4ml/g glucose was obtained at 3:1 of BC/Fe<SUP>2+</SUP>. </LI> <LI> Fe<SUP>2+</SUP> and BC showed synergistic effects on biohydrogen production. </LI> <LI> BC value chain was expanded by the use as additive in hydrogen fermentation. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Effects of biochar (BC) and ferrous iron (Fe<SUP>2+</SUP>) additions on hydrogen (H<SUB>2</SUB>) production from glucose were investigated. Results showed that suitable Fe<SUP>2+</SUP> concentration could enhance [Fe-Fe]-hydrogenase activity, while BC addition could facilitate hydrogen-producing bacteria growth. Both of them could synergistically improve H<SUB>2</SUB> production, indicating a simple, cost effective and practical process.</P> <P>[DISPLAY OMISSION]</P>