Abstract
Fast expanding industries raise concerns about the role of magnetic nanoparticles in environmental applications; however, the impact of these nanoparticles on bacterial behavior in wastewater treatment remains unknown. The present research assessed the role of greenly prepared magnetic iron oxide nanoparticles (Fe3O4 NPs) on the bioremediation of dairy effluent using selected microbial isolates. Three bacterial species (Proteus mirabilis, Pseudomonas batumici, and Providencia vermicola) were isolated from the dairy sludge. The pure cultures of dairy sludge isolates were effective in dairy effluent bioremediation in terms of BOD5, COD, and TOC reduction. The ranking of BOD5 reduction efficiency is Providencia vermicola > Proteus mirabilis > Pseudomonas batumici. Pure cultures containing different concentrations of Fe3O4 NPs were also prepared to investigate the role of Fe3O4 NPs in dairy effluent bioremediation. The influence of greenly synthesized Fe3O4 NPs on bacterial richness was investigated. The study result documented that greenly synthesized Fe3O4 NPs enhance the growth of the studied bacterial species that is effective in dairy effluent bioremediation. Furthermore, the optimum concentration of Fe3O4 NPs was close to 40 mg L-1. Fe3O4 NPs incorporating cultures show remarkable improvement in dairy effluent bioremediation compared with pure cultures.