Influence of nickel and hematite nanoparticle powder on the production of biohydrogen from complex distillery wastewater in batch fermentation

An application of nano-sized particles for an enhancement of biohydrogen production has gained global attention owing to their inherent potentials. In the current communication, influence of nickel oxide (NiO) and hematite (Fe2O3) nanoparticles (NP) on biohydrogen production have been investigated. The complex distillery wastewater was used as a substrate during batch fermentation test. Results showed that the maximum hydrogen yield (HY) and specific hydrogen production rate (SHPR) of 7.85 mmol/g COD and 16.71 mmol/g VSS.d, respectively, corresponding to sole addition of Fe2O3 (200 mg/L) were approximately 1.2-fold higher than those NiO NP, and representing a 44%, and 196%, enhancement compared to control, respectively. The highest HY and SHPR of about 8.83 mmol/g COD, and 18.14 mmol/g VSS.d, respectively, were obtained for the batch test of complex distillery wastewater with co-addition of Fe2O3 (200 mg/L) plus NiO NP (5 mg/L). The results of present study impeccably implies that the co-addition of Fe2O3 and NiO NP is about 1.2–4.5 order more effective for enhanced hydrogen recovery from complex distillery wastewater compared to control, and sole nanoparticles addition. Furthermore, an enhanced activity of ferredoxin oxidoreductase and hydrogenase at Fe2O3 plus NiO nanoparticles interface could be a plausible reason for an observed highest relative enhancement in HY, 62%, and SHPR, 221%, during batch test.