초록
<P><B>Abstract</B></P> <P>Fermentation experiments were designed to elucidate the functional role of the redox microenvironment on volatile fatty acid (VFA, short chain carboxylic acid) production and co-generation of biohydrogen (H<SUB>2</SUB>). Higher VFA productivity was observed at pH 10 operation (6.3g/l) followed by pH 9, pH 6, pH 5, pH 7, pH 8 and pH 11 (3.5g/l). High degree of acidification, good system buffering capacity along with co-generation of higher H<SUB>2</SUB> production from food waste was also noticed at alkaline condition. Experiments illustrated the role of initial pH on carboxylic acids synthesis. Alkaline redox conditions assist solubilization of carbohydrates, protein and fats and also suppress the growth of methanogens. Among the carboxylic acids, acetate fraction was higher at alkaline condition than corresponding neutral or acidic operations. Integrated process of VFA production from waste with co-generation of H<SUB>2</SUB> can be considered as a green and sustainable platform for value-addition.</P> <P><B>Highlights</B></P> <P> <UL> <LI> VFA production from food waste fermentation at variable redox conditions. </LI> <LI> Short chain carboxylic acids synthesis was higher at alkaline pH. </LI> <LI> Higher H<SUB>2</SUB> production was also observed at alkaline pH. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>