Research Information System
Biofuels like biobutanol and biohydrogen from lignocellulosic biomass, including waste figs, offer sustainable alternatives to fossil fuels. This study examined the impact of divalent cations (Zn2+, Mg2+, Mn2+) and electron mediators (neutral red, methyl viologen) on acetone–butanol–ethanol (ABE) fermentation. A one-factor-at-a-time design revealed that Zn2+ slightly boosted hydrogen production, while Mn2+ had negligible effects. Low Mg2+ concentrations (400 mg/L) significantly enhanced hydrogen yield (1300 mL), whereas methyl viologen (MV) and neutral red (NR) inhibited it. Organic acid production varied: divalent cations and mediators did not improve acetic acid yields, but low concentrations increased butyric acid, peaking at 9.0 g/L with 400 mg/L Mg2+. Ethanol, butanol, and acetone production peaked at 15 mM NR, 15 mM MV, and 56 mg/L Mn2+, respectively. These findings demonstrate the potential of fig waste in ABE fermentation, supporting a circular economy by converting hazardous waste into valuable biofuels. This approach aligns with global carbon neutrality and energy security goals, offering an eco-friendly fossil fuel alternative.
