Synthesis, Characterization, and Effective Adsorption of Naproxen Sodium from Wastewater Using Eco-Friendly Gum Acacia-Grafted-Poly(N,N-Dimethylacrylamide)/CoFe2O4 Hydrogel Nanocomposite

Water scarcity and declining water quality, made worse by pharmaceutical waste, pose significant challenges worldwide. There is a high demand to eliminate such contaminants from wastewater. In this study, authors have synthesized a Gum acacia-g-poly (N,N-dimethylacrylamide)/CoFe₂O₄ nanocomposite hydrogel adsorbent by free radical polymerization technique using N,N-dimethylacrylamide (DMA) monomer, and cobalt ferrite (CF) nanofillers. The structural, morphological, and thermal properties of the synthesized nanocomposite hydrogel were characterized by Fourier-transform infrared spectroscopy (FTIR), powder X-ray diffraction (XRD), scanning electron microscopy (SEM), point zero charge (pH_PZC)_, Brunauer–Emmett–Teller (BET) analysis, and thermogravimetric analysis (TGA). XRD analysis revealed a semi crystalline structure with distinct peaks corresponding to CoFe₂O₄, indicating increased crystallinity upon adding CF nanoparticles. SEM images showed a porous surface morphology with CF dispersed throughout the hydrogel matrix, leading to an increased BET surface area of 0.7099 m² g⁻¹ compared to the hydrogel without nanofillers. The effectiveness of the GA-g-P(DMA)/CF nanocomposite hydrogel for removing the non-steroidal anti-inflammatory drug (NSAID) naproxen sodium (NS) from aqueous solutions was investigated. Adsorption experiments were conducted under various conditions including solution pH (2 − 11), adsorbent dose (10–100 mg), initial drug concentration (25–200 mg/L), contact time (2–24 h), and temperature (20–60 °C). The maximum adsorption capacity (q_max) of the hydrogel for NS was determined to be 344.827 mg/g, and the Langmuir isotherm model provided the best fit for the experimental data. The pseudo-second-order kinetic model described the adsorption kinetics well. Electrostatic interactions and hydrogen bonding were identified as the main mechanisms for NS adsorption onto the hydrogel. Furthermore, adsorption − desorption studies demonstrated that the hydrogel could be efficiently recovered and reused for four consecutive runs without significant loss in adsorption performance.