Effects of N/C, P/C and Fe/C ratios on dark fermentative hydrogen gas production from waste paper towel hydrolysate

The effects of N/C, P/C and Fe/C ratios on dark fermentative hydrogen gas production from activated carbon treated WPT hydrolysate were investigated using Box-Behnken statistical experiment design. N/C, P/C and Fe/C ratios were chosen as independent variables while the H-2 yield and SHPR were set as the objective functions. H-2 yield and SHPR functions were described by two quadratic model functions. The addition of a proper amount of N, P and Fe to the fermentation media was found to be essential to enhance the H-2 production performance. Linear and interaction terms of N/C and Fe/C did have a significant effect on the H-2 yield in the model function. However, the SHPR was significantly affected by the linear and interaction terms of N/C and P/C. The most convenient N/C, P/C and Fe/C ratios resulting maximum H-2 yield (0.656 mol H-2/mol glucose) and SHPR (241.64 mL H-2/g biomass.h) were determined as 0.05, 0.09 and 0.003 (w/w), respectively. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.