Degradation of cefixime antibiotic by heterogeneous catalytic ozonation process using novel LDH/zeolite nano-composite: modeling and optimization process.

Abstract

In recent decades, the indiscriminate use of antibiotics and their discharge into the environment have caused serious consequences for aquatic and terrestrial organisms. The present study investigates the optimization of cefixime antibiotic decomposition by a powerful catalytic ozonation process. In this study, the MgAl-LDH /zeolite nanocomposite was synthesized and used as an ozonation-adsorption catalyst to degrade Cefixime antibiotic from an aqueous solution. XRD, FE-SEM, and FTIR analyses were scrutinized to reveal the main characteristics of the as-prepared nanocomposite, showing that it was well-synthesized. The investigated variables in the catalytic ozonation of Cefixime by the mentioned nanocomposite included solution pH level (5-9), nanocatalyst dose (0.5-2.5 g/L), Cefixime concentration (5-25 mg/L) and reaction time (5-60 min) which they were optimized by adopting RSM-CCD. The results showed that all variables positively affected the efficiency of the catalytic ozonation process. Nonetheless, the lowest effect of operational factor pH, the degradation of Cefixime was subjected to the initial content of Cefixime in this treatment system. The optimal conditions for cefixime removal by catalytic ozonation process were determined at pH of 7.72, nanocatalyst dosage of 1 g/L, cefixime concentration of 23 mg/L, and reaction time of 55 min. In the optimized operating conditions, the removal efficiency of Cefixime by MgAl-LDH /zeolite nanocomposite was high, up to 98.37%, and It is suggested that due to the high efficiency of this process, it can be used in the treatment of pharmaceutical wastewater.

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