Effect of Organic Acids Stress on Biohydrogen Production by Anaerobic Granular Sludge

Abstract:

The major organic acids produced in the fermentative hydrogen production by mixed cultures were acetic acid, propionic acid, lactate acid and butyric acid, etc. which had negative effect on hydrogen production. The acid tolerance of mixed cultures was improved by the metabolites stress and the sludge activities under different stresses were investigated through the dehydrogenase activity (DHA) determination in the work. The results showed that certain metabolite stress could increase the hydrogen production and the metabolite yield, especially when acetic acid and butyric acid were used for stress. Importantly, the cumulative hydrogen quantity nearly doubled compared with the control. Interestingly, the acetic acid production enhanced extensively regardless of the stress method of all groups.