| Abstract: | The procedure for starting‐up continuously stirred tank reactors (CSTR) for acclimating anaerobic hydrogen‐producing microorganisms with sewage sludge was investigated. Initially, feeding with glucose and sucrose as well as mixing were carried out in semicontinuous mode; hydraulic retention time (HRT) was in an order of 20, 15, 10, 5, 2.5 and 2 days. When the pH declined to its lowest value (pH 5.18), it was adjusted to 6.7 using sodium hydroxide (1 N). At the same time, the semi‐continuous operation was changed to a continuous one. Finally, the pH was continuously regulated at approximately 6.7. The results indicate that this procedure can be used to cultivate seed sludge for hydrogen production from sewage sludge resulting in a large hydrogen production in less than 60 days. When the substrate was glucose, a hydrogen yield of 1.63 mol H2/mol glucose and a specific hydrogen production rate of 321 mmol H2/g VSS day at an HRT of 13.3 h was achieved. When the substrate was sucrose with the same HTR, a hydrogen yield of 4.45 mol H2/mol sucrose and a specific hydrogen production rate of 707 mmol H2/g VSS day was obtained. |
