The Impact of Fe2+ and Na+ Concentrations on Hydrogen Production with Three Different Fermenter Bacteria

Abstract

Batch experiments were conducted to investigate the effects of Fe²⁺ and Na⁺ on the hydrogen (H₂) production performance from three different metabolic type hydrogen-producing bacterial strains. The appropriate amount of Fe²⁺ significantly promoted the H₂ production of all three hydrogen-producing bacteria. The combination of H₂ production and liquid products showed that Fe²⁺ was more suitable for the H₂ production and metabolism of E. harbinense ZGX4. When the Fe²⁺ concentration was 0.05 g/L, the H₂ production and liquid products concentrations were 2170 mL/L-medium and 6530 mg/L, respectively. Na⁺ enhanced the H₂ production of E. harbinense ZGX4 and C. butyricum 1.209 but inhibited the H₂ production of E. cloacae 1.2022. Na⁺ made C. butyricum 1.209 exhibit the best H₂ production and metabolic performance when the Na⁺ concentration was 2 g/L, while the H₂ production, and liquid products concentration were 2460 mL/L-medium and 5350 mg/L, respectively. At the end of the experiment, it was found that the addition of Fe²⁺ could change the type of fermentation in C. butyricum 1.209. Therefore, further exploration of the effects of other metal ions on model hydrogen-producing strains has great potential for achieving high hydrogen production rates, among other things.