ABSTRACT

 Zinc oxide nanoparticles are known for their adsorption properties and multifunctional features that aid pollution remediation. It finds its application in the removal of dyes and agricultural pollutants such as pesticides. In this research, zinc oxide was synthesized by precipitation method using zinc acetate and sodium hydroxide as precursors. The synthesized zinc oxide nanoparticles were further modified using Oleic acid and Aluminium oxide. The resulting nanoparticles were characterized by Scanning Electron Microscope (SEM), XRay diffraction (XRD) and Fourier Transform Infra-Red (FTIR). Adsorption applications of zinc oxide nanopartic/es for the removal of glyphosate and cypermethrin pesticide pollutant were conducted The conditions for the adsorption of pesticides under investigation by modified and unmodified zinc oxide nanoparticles were: adsorbent dosage (0.1 g, 0. 2g, 0.4g and 0.6g), contact time (10mins, 20mins, 30mins, 40mins, 50mins and 80mins), concentration of the pesticide (20mL, 3.0mL, 4.0mL, 4.5mL and 6.5ml) and pH (3, 5,7, 9). The adsorbent was characterized before and after adsorption using Fourier transform Infra-red (FTIR). Experimental data were tested with four different isotherm model: Langmuir, Freundlich, Dubinin-Raduskevich and Temkin isotherms. Results showed that the two pesticides, glyphosate and cypermethrin, had better adsorption onto unmodified zinc oxide nanopartic/es followed by organic modified nanoparticles. The highest adsorption occurred at pH 7 for glyphosate and pH 9 for cypermethrin. The highest adsorption occurred at the mass of 0. 6 g of the unmodified, inorganic modified and organic modified nanoparticles. The adsorption rate increased with time, highest adsorption was recorded at 80 mins for the three adsorbents.