Sustainable green synthesis and statistical optimization of Co@Cu–MOF/alginate beads for efficient antibiotic adsorption from aqueous systems

Abstract

The growing prevalence of antibiotic pollutants in aquatic habitats presents significant health and ecological hazards, making the creation of efficient and sustainable remediation techniques imperative. Co@Cu–MOF embedded alginate beads were manufactured in this study adopting a facile and environmentally friendly method, and they were utilized as a novel adsorbent to remove antibiotics from aqueous solutions. Alginate's inexpensive cost and biological compatibility as a natural support matrix were utilized in the manufacturing procedure in order to boost the MOF material's stability, flexibility, and recyclability. A series of characterization approaches, including x-ray diffraction patterns, Fourier transform infrared spectroscopy, scanning electron microscopy, and energy-dispersive x-ray spectroscopy analyses were used to describe the synthesized material's shape and elemental composition, indicating that the in situ synthesis of Co@Cu-based MOFs with alginic acid was achieved. Response surface methodology was used to comprehensively optimize the adsorption performance at pH (3–10), initial antibiotic concentration (10–100 mg/L), adsorbent dosage (0.02–0.35 g/L), and duration of contact (5–80 min) and validate the model. The Co@Cu–MOF/alginate beads demonstrated a high adsorption capacity of 95.75 mg/g and great affinity toward antibiotic molecules under the ideal conditions (pH 9, 45 min contact duration, and 0.17 g adsorbent dosage). Multilayered adsorption was confirmed by the equilibrium following the Freundlich isotherm and the kinetic data fitting well with the pseudo-second-order model. After four regeneration cycles, the beads maintained more than 90% of their efficiency, demonstrating stability and reusability and ecofriendly treatment of antibiotic-polluted water.