Increasing biohydrogen production from swine wastewater influenced by anaerobic consortium and nickel ferrite nanoparticles

Abstract

Screening of efficient microbial consortia and supplementing nanoparticles for pure hydrogen gas evolution have recently become urgent issues in the field of wastewater-derived hydrogen production. In this study, a newly isolated anaerobic consortium combining with nickel ferrite (NiFe2O4) nanoparticles (NPs) was applied to increase the biohydrogen production from swine wastewater. The suitable swine-wastewater-to-rice-straw-hydrolysate proportion was determined as 2:3, which corresponded to a cumulative hydrogen production of 1560.4 ± 10.3 mL/L. The addition of 200 mg/L NiFe2O4 NPs was found to be the most favorable for hydrogen gas evolution, resulting in a cumulative hydrogen production that was 21.8 % higher than that of the control (0 mg/L). Moreover, with the optimal dose (200 mg/L) of NiFe2O4 NPs, butyric acid was converted to the dominant volatile fatty acid, the microbialcommunity was dominated by Clostridium_sensu_stricto and Rummeliibacillus, and the relative expression of hydrogenase gene increased 175.4 ± 31.7-fold after 24 h of fermentation. The changes in microbial metabolism, distribution, and hydrogenase gene expression are helpful to increase the biohydrogen production with the addition of optimal dose of NiFe2O4 NPs.