Evaluation of Antimicrobial Activity of Zinc Oxide Nanoparticles in Animal farm Wastewater

Abstract

This study evaluates the antimicrobial activity of zinc oxide (ZnO) nanoparticles against resistant microbial populations in the animal farm wastewater source. ZnO nanoparticles were synthesized via a chemical precipitation method and characterized using Scanning Electron Microscopy/Energy Dispersive X-ray (SEM/EDX) and Fourier-Transform Infrared Spectroscopy (FTIR) to analyze surface morphology and functional groups. The antimicrobial potential was assessed by investigating the effects of nanoparticle dosage, pH, and contact time. Animal wastewater samples were cultured in nutrient broth, and ZnO nanoparticles were introduced in varying concentrations of 10%, 20%, and 30%. The pH was adjusted to 3, 7, and 9, and the samples were incubated for up to 72 hours. Microbial growth was monitored through optical density (OD) measurements taken at 280 nm, allowing for quantitative analysis of microbial inhibition over time. Results showed a significant decrease in OD values with increasing nanoparticle concentration and extended incubation time. The highest antimicrobial efficiency was observed at alkaline pH (9), indicating a strong correlation between environmental conditions and ZnO nanoparticle activity. Overall, this study demonstrates that ZnO nanoparticles can effectively reduce microbial load in wastewater under optimized conditions, supporting their potential as a sustainable and low-cost antimicrobial agent in environmental applications. Future research should focus on pilot-scale implementation and testing against specific resistant bacterial strains.