초록
The effects of Fe<SUP>0</SUP> and Ni<SUP>0</SUP> nanoparticles on mesophilic dark hydrogen fermentation from starch were investigated using heat-shock pretreated anaerobic sludge in batch reactors. Starch concentration in the range of 0-20 g/L was used in the presence of 0-50 mg/L of each Fe<SUP>0</SUP> and Ni<SUP>0</SUP> nanoparticles while the initial pH of all experiments was adjusted to 7. The hydrogen production was optimized using response surface methodology (RSM) in a central composite design (CCD) mode. The results showed the significance of the linear effect of starch and Fe<SUP>0</SUP> concentrations, the interactive effect between Fe<SUP>0</SUP> and Ni<SUP>0</SUP> concentrations, and the squared effect of starch concentration on the biohydrogen production. The maximum yield of hydrogen production 149.8 mL/g-VS was obtained at starch, Fe<SUP>0</SUP> and Ni<SUP>0</SUP> concentrations of 5.37 g/L, 37.5 mg/L, and 37.5 mg/L, respectively. This was nearly 200% higher than those in the corresponding control test. Moreover, the analysis of metabolites indicated the hydrogen production through acetic acid pathway.