Layered magnesium oxide for efficient removal of fluoride from groundwater

Abstract

This study presents a novel layered magnesium oxide (MgO) adsorbent synthesized using a sodium dodecylbenzene sulfonate (SDBS)-assisted hydrothermal method aimed at enhancing fluoride removal from water. The optimized MgO sample exhibited a specific surface area of 164.7 m² g⁻¹ and an average pore size of 5.4 nm, achieving a fluoride removal rate of 91.95% at an initial concentration of 10 mg L⁻¹ over a wide range of pH. Adsorption studies revealed a maximum capacity of 126.405 mg g⁻¹, aligned with the Langmuir isotherm model and pseudo-second-order kinetics. The fluoride removal mechanism involves converting MgO to Mg(OH)₂ followed by ion exchange processes, elucidated through X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). The adsorbent demonstrated good regeneration potential and pH tolerance across varying conditions. Notably, fluoride-adsorbed MgO showed enhanced catalytic activity in Knoevenagel condensation reactions and plastic degradation, indicating its dual functionality in both water treatment and catalysis. This research offers valuable insights into developing multifunctional materials for environmental remediation and catalytic applications, addressing critical challenges in water treatment technologies.