Insights into correlation between hydrogen yield improvement and glycerol addition in photo-fermentation of Arundo donax L.

Abstract This study aimed to explore the correlation between hydrogen yield improvement of photo-fermentation of Arundo donax L. and glycerol addition. Different glycerol concentrations (g/L) (0, 10, 15, 20, and 30) were replenished to establish co-substrate system. And statistical analysis was introduced to evaluate the correlation. The maximum hydrogen yield improvement (294 %) was obtained from glycerol addition of 15 g/L in comparison with mono-substrate system of Arundo donax L.. Under the optimal glycerol addition (15 g/L), the glycerol/Arundo donax L. ratio, C/N ratio, initial medium redox potential (Eh), and solid/liquid ratio were 1:1, 25.1, 57 mV, and 1/68, respectively. In addition, canonical correlation analysis (CCA) indicated that initial and final medium redox potential (Eh) had the strongest relationship with yield improvement of photo-fermentation. Moreover, Pearson’s correlation analysis claimed that Arundo donax L./glycerol ratio played a key role during the photo-fermentative hydrogen production (PFHP) process.