SIMULTANEOUS REMOVAL OF ANTIBIOTIC AND ANTIBIOTIC RESISTANT BACTERIA BY NANOMATERIAL

Abstract

The increasing prevalence of antibiotics in water systems poses significant environmental and health concerns, including antibiotic resistance and genotoxicity. This research focuses on synthesizing FeWO4 nanomaterials in three distinct morphologies- nanoparticles, nanorods, and nanofibers via a sustainable hydrothermal process. These nanomaterials were evaluated as heterogeneous catalysts in four different Fenton-based processes: conventional Fenton (CF), photo-Fenton (PF), sono-Fenton (SF), and sono-photo-Fenton (SPF). The performance of each morphology was systematically assessed for the degradation of ciprofloxacin (CIP), a common antibiotic pollutant found in water. The synthesized nanomaterials were characterized using UV-Vis, FESEM, XRD, XPS, EIS, and cyclic voltammetry (CV). The physicochemical analysis also confirmed differences in catalytic performance based on changes in their morphologies. The Response Surface Methodology (RSM) and Central Composite Design (CCD) were used to improve the degradation of CIP by altering three independent variables: solution pH, catalyst dose (mg/L), and reaction time (min). The quadratic model was found to be significant through analysis of variance (ANOVA). This mathematical model fits the experimental data satisfactorily, with R2 = 0.9953 and lack of fit = 0.2441 (P>0.05). Almost complete degradation was achieved at the optimum doses of 100 mg/L of FeWO4, pH = 7, and a 40-minute reaction time. Among the Fenton processes, PF and SPF demonstrated higher antibiotic degradation efficiency than CF and SF processes. Notably, FeWO4 nanoparticles exhibited the best performance, achieving complete degradation of CIP under optimized conditions of pH 7, FeWO4 dosage of 100 mg/L, and a reaction time of 40 minutes, with initial concentrations of 10 mg/L for CIP and 2 mM for hydrogen peroxide (H2O2). FeWO4 nanoparticles were found to be effective for inactivation of ARB E. Coli RP4 by 6.45 log within 20 min. No ARB regrowth occurred after 72 h, which demonstrates the efficacy of this approach in achieving permanent removal of ARB. The synthesized FeWO4 nanoparticles have the potential to degrade demonstrated stability and recyclability, generating potent reactive species such as hydroxyl radicals (HO•), superoxide radicals (O2 •-), and singlet oxygen (1O2). These findings underscore the potential of FeWO4 nanoparticles as effective heterogeneous catalysts in advanced oxidation processes for mitigating antibiotics and antibiotic-resistant bacteria in aquatic environments.