Unraveling the mechanism of increased synthesis of hydrogen from an anaerobic fermentation by zinc ferrate nanoparticles: Mesophilic and thermophilic situations comparison

Abstract

In this work, ZnFe2O4 NPs were created using the pyrolysis process, and its effects on thermophilic (TF) and mesophilic (MF) fermentation were examined. In MF, the maximum hydrogen yield (MHY) occurred in the 50 mg/L ZnFe2O4 NPs group (228.01 mL/g glucose), which was 45.24% higher than that of the control group (157.01 mL/g glucose). While in TF, MHY appeared in 100 mg/L ZnFe2O4 NPs was 149.12 mL/g glucose, which was 38.83% higher than the control group (107.41 mL/g glucose). ZnFe2O4 NPs boosted the synthesis of ferredoxin, hydrogenase, and ethanol dehydrogenase by increasing the generation of butyrate in MF and acetate in TF. Moreover, Clostridium sensu stricto 5 and 10 in MF and TF rose by 9.20% and 9.40%, respectively, due to the increased abundance of predominant hydrogen-producing bacteria by ZnFe2O4 NPs.