Process parameter optimization and enhancement of photo-biohydrogen production by mixed culture of Rhodobacter sphaeroides NMBL-02 and Escherichia coli NMBL-04 using Fe-nanoparticle

摘要

In this study, comparative enhancement effect of nanoparticle form and bulk form of Fe(SO4)OH(H2O)(2) on hydrogen production by mixed culture of Rhodobacter sphaeroides NMBL-02 and Escherichia coli NMBL-04 was investigated in batch process. The maximum cumulative hydrogen production and % substrate conversion efficiencies were observed at 300 mg/L Fe(SO4)OH(H2O)(2) concentration (Fe-concentration) with nano as well as bulk form. But the results obtained with nano form of Fe(SO4)OH(H2O)(2) were 1.2 fold higher in contrast to bulk form. Further optimization studies were also performed with two more factors namely pH and malate concentration. Response surface methodology (RSM) in accordance with Box-Behnken Design was employed to evaluate the interactive effects of these factors. From RSM the optimum values of pH and, malate concentration and Fe-concentration were obtained as 5.603, 3.948 g/L and 312.168 mg/L respectively.