Kinetics analysis of PAHs degradation using SiO2-ZnO nanoparticles and evaluating their antibacterial and antibiofilm efficacy.

ABSTRACT

The adsorption of Polycyclic aromatic hydrocarbons (PAHs) using nanoparticles is gaining significant attention due to the rapid removal or treatment rates. In this study, Silicon Dioxide-Zinc Oxide nanoparticles (SiO2-ZnO NPs) were synthesized to adsorb pyrene. Physicochemical characterization of SiO2-ZnO NPs showed plasmon resonance at 323 nm, agglomeration, irregular dispersion, and diameters of 90-100 nm. FT-IR analysis identified major functional groups on SiO2-ZnO NPs, including alkyne, amine, and isothiocyanate. SiO2-ZnO NPs demonstrated significant pyrene adsorption at pH 5, with 10 µg/mL of SiO2-ZnO NPs and 2 µg/mL of PAHs, performing better under UV irradiation. Two isotherm models, adsorption isotherm and kinetics adsorption, were used to analyze the PAHs adsorption by SiO2-ZnO NPs. Additionally, SiO2-ZnO NPs were tested for antibacterial and antibiofilm activities against both Gram-negative and Gram-positive bacteria. At a concentration of 150 µg/mL, SiO2-ZnO NPs produced inhibition zones of 21.57 mm, 20.30 mm, 19.30 mm, and 11.30 mm against Staphylococcus aureus, Escherichia coli, Bacillus subtilis, and Klebsiella pneumoniae, respectively. They also inhibited and disrupted biofilms of Micrococcus luteus and Acinetobacter baumannii. Furthermore, SiO2-ZnO NPs exhibited photocatalytic degradation of lead, achieving 68.24% degradation within 5 h of treatment. Therefore, SiO2-ZnO NPs are efficient candidates for multiple applications, including pyrene adsorption, bacterial biofilm disruption, and lead degradation under sunlight.