Biohydrogen Production Using Anaerobic Fermentation at Various pH Values

Abstract

Hydrogen production with waste water can reduce pollution and produce clean energy at the same time. Hydrogen production is affected by many factors. In this experiment, with automatic fermentor, hydrogen and acid production, as well as organic removal rates from brown sugar wastewater by anaerobic cultures at various pH values, are studied. Results showed that the highest hydrogen production efficiency could be achieved when the pH value was maintained at 6.0. The maximum hydrogen production was 61.1mlH2/(g.VSS.d), and COD removal rate reached up to 33.8%, relatively higher than other pH values. The acid production was significantly improved under the condition of pH=4.5. However, the composition of VFAs was similar at the different pH values. The amount of acetic acid and butyric acid was account for about 90% of the final liquor products, and only a little propionic acid has being detected. The TOC removal rate in the system under different pH conditions are increase with pH value, but all below 10%. As the reaction proceeds, the propionic acid accumulation were also observed, higher pH could decrease the producing rate of it.