The effect of adding zero-valent iron nanoparticles on biohydrogen production from refectory waste

Abstract

The objective of the current research was to increase biogas and biohydrogen production by adding zero-valent iron nanoparticles (Fe0NPs) to refectory waste by the dark fermentation method. Loading was done at 0, 2, 4, 8, and 10 gVS/gVS ratios to determine the highest S/I ratio. The best yield was obtained at the S/I loading ratio of 4 gVS/gVS. Different Fe0NP concentrations (0, 50, 100, 200 and 400 mg/L) were studied at the best loading rate. The highest biogas (86%) and biohydrogen production (140%) occurred at a Fe0NP concentration of 100 mg/L. The highest TS and VS removal were determined as 50% and 37%, respectively, in the reactor with the 100 mg/L Fe0NP concentration added. The highest total VFA concentration was observed at the S/I loading ratio of 4 gVS/gVS and 100 mg/L Fe0NP concentration added. Considering biogas and biohydrogen production, biofilm samples were taken from the S/I = 4 gVS/gVS reactor with the highest efficiency and the best results in the addition of Fe0NP, and as a result of examining their microbial distribution, Lactobacillus, Pseudomonas, and Clostridium were determined as the most dominant species.