Enhancement of biohydrogen production in industrial wastewaters with vinasse pond consortium using lignin-mediated iron nanoparticles

Abstract

The aim of this work was the enhancement of biohydrogen production by an anaerobic bacterial consortium with incorporation of lignin-mediated iron nanoparticles in the fermentation medium. Lignin magnetic nanoparticles (LMNP), identified as magnetite by XRD, exhibited spherical shape and average particle size of 8.6 nm, while lignin non-magnetic nanoparticles (LNMNP) exhibited high agglomeration and an amorphous nature in TEM and XRD, respectively. The fermentation medium (pH 7) was composed of 88% soft drink wastewater (SDW) and 12% corn steep liquor (CSL) and supplemented with NaHCO3 (1.0 g/L) and cysteine-HCl (0.5 g/L). Under optimal conditions, BioH2 production was 17.67 ± 0.54 mL, after 48 h of fermentation at 37 °C. Addition of LMNP and LNMNP increased BioH2 production in 91.0 and 74.3%, respectively. Additionally, 200 mg/L of LMNP and LNMNP in the fermentation medium improved the BioH2 yields (mL H2/g CODremoved) in 2.8- and 2.3-fold, respectively.