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Influence of initial pH on hydrogen production from cheese whey

2005; Elsevier BV; Volume: 120; Issue: 4 Linguagem: Inglês

10.1016/j.jbiotec.2005.05.017

1873-4863

Mongi Ferchichi, Edward Crabbe, Gwang-Hoon Gil, William E. Hintz, Amer Almadidy,

Biofuel production and bioconversion

Batch experiments were conducted to investigate the effect of initial pH, between 5 and 10, on fermentative hydrogen production from crude cheese whey (87.5% (v/v) by Clostridium saccharoperbutylacetonicum). Hydrogen was produced over the range of pH studied. The hydrogen production rate and yield peaked at an initial pH 6 and then steadily decreased as the pH increased. The highest rate and yield were 28.3 ml h−1 and 7.89 mmol g−1 lactose, respectively. Sugar consumption was unaffected between pH 5 and 9 and remained at 97%. All final pHs were acidic and increased alongside the initial pH. There was no correlation between the initial pH and the fermentation time; the times were shorter (50–52 h) between pH 6 and 8, and longer (62–82 h) outside this range. A modified Gompertz equation adequately described fermentative hydrogen production from cheese whey. The respective maximum hydrogen production rate and hydrogen potential at an optimal pH of 6 were 47.07 ml h−1 and 1432 ml. Lag phase times were much longer at acidic pHs than at alkaline pHs.