Integrated persulfate/ozonation process using Fe3O4/AC catalyst for antibiotic degradation - optimization and kinetic insights

Sep 30, 2026

Antibiotics are persistent emerging contaminants, and cefixime is frequently present in pharmaceutical effluents, demanding efficient removal. The study optimized catalytic ozonation for cefixime degradation by activating persulfate with magnetic activated carbon (Fe3O4/AC). Influences of pH (5–11), contact time (5–60 min), catalyst dose (0–2.5 g/L), initial cefixime concentration (10–200 mg/L), and persulfate concentration (0–70 mM) were evaluated. Central composite design with response surface methodology modeled and validated performance (R2 = 0.90). Reaction time and pH were most significant. At pH 8, cefixime 57.5 mg/L, MAC 1.5 g/L, persulfate 1.75 mM, and 46.25 min contact time, 97% removal was achieved, supporting potential pharmaceutical wastewater application.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages16

Reading Time40 min

AccessFree to download

Introduction

Antibiotics as emerging contaminants

Cefixime: properties and environmental concerns

Limits of conventional wastewater treatment

Rationale for advanced oxidation processes

Methods and Process Optimization

Catalytic ozonation with persulfate activated by Fe3O4/AC

Factors evaluated and experimental design

Statistical modeling and kinetic insights

Results and Discussion

Model performance and key influencing variables

Optimal operating conditions and removal efficiency

[www. nature.com/scientificreports](www. nature.com/scientificreports) OPEN Integrated persulfate/ozonation process using Fe 3 O4/AC catalyst for antibiotic degradation: optimization and kinetic insights Zahra Shahbeiki1, Hojjat Nadimi2,3, Maryam Khodadadi4􀀍 & Yousef Dadban Shahamat5􀀍 Antibiotics are considered emerging contaminants due to their persistence and potential ecological risks. Among them, cefixime is frequently detected in pharmaceutical effluents and requires effective removal strategies. This study aimed to optimize catalytic ozonation for cefixime degradation using persulfate activated by magnetic activated carbon (Fe3O4/AC or MAC). The effects of pH (5–11), contact time (5–60 min), catalyst dose (0–2.5 g/L), initial cefixime concentration (10–200 mg/L), and persulfate concentration (0–70 mM) were evaluated. A central composite design (CCD) under response surface methodology (RSM) was applied to model and optimize the process. Model performance was assessed by statistical indicators. The quadratic model showed good predictive ability (R2 = 0.90) . Reaction time and pH were the most significant variables influencing cefixime degradation. Under optimized conditions (pH 8, cefixime 57.5 mg/L, MAC 1.5 g/L, persulfate 1.75 mM, and 46.25 min contact time), 97% removal efficiency was achieved. The findings indicate that catalytic ozonation activated with persulfate and MAC is an effective and statistically validated process for cefixime removal from aqueous solutions. These results support its potential applicability for pharmaceutical wastewater treatment. Keywords Cefixime, Advanced oxidation processes, Catalytic ozonation, Magnetic activated carbon, Persulfate, RSM Pharmaceutical residues, particularly antibiotics, are increasingly recognized as serious environmental contaminants due to their extensive and often indiscriminate use in medicine, agriculture, and industry1. Classified as contaminants of emerging concern (CECs), they reach aquatic systems mainly through hospital effluents, industrial discharges, and direct excretion in unmetabolized forms2. Reports show that 30–90% of antibiotics can be excreted unchanged, with concentrations up to 1 mg/L detected in wastewater—levels considered environmentally significant by the United States Environmental Protection Agency (EPA)3,4. The recent surge in antibiotic consumption during global health crises such as the COVID-19 pandemic has further intensified concerns, highlighting the persistent environmental footprint of these compounds5. Among antibiotics, beta-lactams are of particular interest due to their clinical effectiveness and widespread prescription6. Cefixime (Table 1), a third-generation cephalosporin, is commonly used to treat respiratory, urinary, gastrointestinal, and dermatological infections7. Its popularity stems from broad antimicrobial activity, affordability, and accessibility8. However, cefixime is poorly metabolized in the human body, and its complex molecular structure resists biodegradation. As a result, residues persist in aquatic environments, where they may disturb ecological balance, promote antimicrobial resistance, and pose risks to public health8. In addition, interactions of cefixime with chlorine during disinfection can form toxic or carcinogenic by-products, exacerbating its environmental impact8. Conventional wastewater treatment technologies are generally ineffective in addressing such persistent antibiotics9. Adsorption, biological processes, and coagulation–flocculation can remove some contaminants, 1Student Research Committee, Birjand University of Medical Sciences, Birjand, Iran. 2Department of Environmental Health Engineering, School of Health, Tehran University of Medical Sciences, Tehran, Iran. 3Students’ Scientific Research Center (SSRC), Tehran University of Medical Sciences, Tehran, Iran. 4Department of Environmental Health Engineering, School of Health, Medical Toxicology and Drug Abuse Research Center

FAQs

What is the study’s main goal for treating cefixime in water?

To optimize a catalytic ozonation process in which persulfate is activated using magnetic activated carbon (Fe3O4/AC) for cefixime degradation.

Which variables were investigated as key factors affecting cefixime removal?

pH (5–11), contact time (5–60 min), catalyst dose (0–2.5 g/L), initial cefixime concentration (10–200 mg/L), and persulfate concentration (0–70 mM) were evaluated.

How was the process optimized and how good was the predictive model?

A central composite design under response surface methodology modeled the system, achieving R2 = 0.90 for predictive ability.

What operating conditions produced the highest removal efficiency?

Under optimized conditions (pH 8, cefixime 57.5 mg/L, MAC 1.5 g/L, persulfate 1.75 mM, and 46.25 min contact time), 97% removal efficiency was achieved.

Sep 30, 2026

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