Fermentative hydrogen production using enriched anaerobic sewage sludge microflora

摘要

Sucrose anaerobic acidogenesis was conducted in three completely stirred tank reactors operating at 35°C to investigate the characteristics of biological hydrogen production using sewage sludge microfloraas the seed. The seed sludge was separately enriched with base (1N NaOH), acid (1N HCl) and heated(100 °C for 45 min) to inhibit hydrogen-consuming microorganism bioactivity. The experimental resultsindicated that the reactors operated stably for more than 240 days at a hydraulic retention time of 12 h.The hydrogen gas content, hydrogen yield and hydrogen production rate ranged 28-38.7%, 1.4-3.5mol-H2/mol-sucrose and 144-367 mmol-H2/L/day, respectively. These hydrogen productivity valueswere comparable to hydrogen production using pure cultures. Base enrichment markedly enhanced thehydrogen productivity. Moreover, based on the hydrogen gas content in the biogas, it was found thatalthough steady-state conditions were obtained, a cyclic 10-days-declining- increasing-decreasinghydrogen production (25% variation referring to the data obtained at the steady-state conditions)occurred in the acid and base-enrichment reactors. Their periods were 85 and 120 days, respectively. Thedistribution variations in volatile fatty acid concentrations could also be used as a useful reactor operatingindex.