Optimisation of the removal of antibiotics from aqueous environments through ultrasonic processing with α-hematite nanoparticles using response surface methodology (case study: cefixime)

Abstract

The occurrence of contamination of emerging concerns (CECs) has turned into a significant challenge. In the present study, the elimination of Cefixime from the aquatic media was optimized. The ultrasonic method, combined through α-hematite nanoparticles, was studied using the response surface methodology (RSM). In this examination, various factors were evaluated to determine their impact, including pH levels (ranging from 5 to 11), nanoparticle dosage (0.05–0.3 g/L), contact time (10–90 min), primary Cefixime concentration (25–100 mg/L), and ultrasound wave frequencies (35–130 kHz). Nanoparticle characteristics were determined through Brunauer–Emmett–Teller (BET) and X-ray diffraction (XRD) analysis. The chemical oxygen demand (COD) was measured to monitor the removal of Cefixime. The outcomes of the data analysis revealed that the catalyst dosage and contact time were the most significant factors influencing the Cefixime removal rate. The optimal conditions determined during the experiments included a pH of 3, an ultrasound wave frequency of 37 kHz, an initial Cefixime concentration of 25 mg/L, a catalyst dosage of 0.25 g/L, and a reaction time of 90 min. Under these conditions, a COD elimination efficiency of 98.7% was attained for Cefixime. The process kinetics adhered to a pseudo-second-order (PSO) model, achieving an R² value of 0.9905. The findings of this research demonstrate the high efficiency of the sonocatalytic removal technique in eliminating Cefixime antibiotics from aqueous solutions.