Adsorption of anti-inflammatory drug diclofenac by MgAl/layered double hydroxide supported on Syagrus coronata biochar

The increasing levels of diclofenac sodium (DS) detection in aquatic environments have been causing great concern, thus the efficient removal of DS is of urgent importance. In this study, for the first time a composite with MgAl/layered double hydroxide supported on Syagrus coronata biochar was fabricated, characterized and used for diclofenac sodium adsorption. The physicochemical characterizations, including X-ray, FT-IR, N₂ adsorption and microscopy, confirmed the composite was successfully synthesized. Adsorption batch experiments demonstrated a high DS removal efficiency (higher of 82% for 200 mg.L⁻¹ of DS). Kinetic and equilibrium studies indicated the limiting adsorption mechanism was chemisorption providing maximum adsorption capacity of 138.83 and 168.04 mg.g⁻¹ at 30 and 60° C, respectively. Thermodynamics suggested DS adsorption was spontaneous, exothermic and created modification in the adsorbent structure.