Effects of volatile fatty acids on a thermophilic anaerobic hydrogen fermentation process degrading peptone

摘要: Hydrogen fermentation using glucose as a single substrate caused abrupt pH drops and the gradual losses of hydrogen producers, which in turn led to system failure. In this study use proteinaceous substrate, peptone, avoided reactive allowed for further exploration volatile fatty acids (VFAs) effects on process. Our results showed that: (1) during tests, were thus stability increased due production ammonia from peptone fermented, (2) control was not necessary addition acetate process had little effect process, (3) at extreme pHs either lengthened lag phase (pH ≤6) or slowed rate ≥ 8), both situations desired, (4) high VFA content sped up consumption gas. Results suggested that protein-containing substances beneficial maintaining pH. As long maintained around 6-8, inhibition VFAs accumulation minimized. Thus, optimal operation would be achievable via composition certain carbohydrate-to-protein ratio.