Dark fermentative hydrogen production from hydrolyzed sugar beet pulp improved by nitrogen and phosphorus supplementation

Abstract

The effect of nitrogen and phosphorous addition on hydrogen production from hydrolyzed Sugar beet pulp (SBP) was investigated using (NH₄)₃PO₄, NH₄Cl and K₃PO₄ as the supplements. In batch tests, the maximal hydrogen production of 279 dm³/kgVS was observed for K₃PO₄, which was added to SBP in a dose of 1 g/dm³. In semi-continuous experiments, the greatest hydrogen production of 36 dm³/kgVS was reported for the same supplement, and this value was twice higher than that of the control run. The analysis of microbiota revealed that the majority of bacteria was affiliated to the orders Clostridiales, Lactobacillales and Coriobacteriales. Moreover, a noticeable methane production was associated with the activity of Methanosphaera sp., which could grow in a low pH environment of dark fermentation.

Keywords: Dark fermentation; Hydrogen; Nitrogen; Phosphorus; Sugar beet pulp.