Biosynthesis approach of zinc oxide nanoparticles for aqueous phosphorous removal: physicochemical properties and antibacterial activities

Abstract In this study, phosphorus (PO43–-P) is removed from water samples using zinc oxide nanoparticles (ZnO NPs). These nanoparticles are produced easily, quickly, and sustainably using Onion extracts (Allium cepa) at average crystallite size 8.13 nm using Debye-Scherrer equation in hexagonal wurtzite phase. The bio-synthesis ZnO NPs characterization and investigation were conducted. With an initial concentration of 250 mg/L of P, the effects of the adsorbent dose, pH, contact time, and temperature were examined. At pH = 3 and T = 300 K, ZnO NPs, the optimum sorption capacity of 84 mg/g was achieved, which was superior to many other adsorbents. The isothermal study was found to be fit the Langmuir model at monolayer capacity 89.8 mg/g, and the kinetic study was found to follow the pseudo-second-order model. The adsorption process was verified to be endothermic and spontaneous by thermodynamic characteristics. As a result of their low cost as an adsorbent and their high metal absorption, ZnO NPs were found to be the most promising sorbent in this investigation and have the potential to be used as effective sorbents for the removal of P from aqueous solutions. The antimicrobial activity results showed that ZnO NPs concentration had a greater antibacterial activity than conventional Cefotaxime, which was utilised as a positive control, in the inhibitory zone. However, there was no inhibitory zone visible in the controlled wells that had been supplemented with onion extract and DMSO.