Efficient Fluoride Removal Using Nano MgO: Synthesis, Mechanisms, and Performance Evaluation

Abstract

Abstract In this study, highly efficient fluoride removal of nano MgO was successfully synthesized using a simple hydrothermal precipitation method. CTMAB was used as a surfactant, and its long-chain structure tightly wrapped around the precursor crystal of basic magnesium chloride, inhibiting the growth of the precursor crystals, reducing their size and improving the dispersion of the crystals, enhancing the adsorption of nano MgO to fluoride. The adsorption performance of nano MgO for fluoride was investigated through the discussion of adsorption isotherms and kinetics,. The results indicate that the adsorption behavior of fluoride by magnesium oxide can be described by pseudo-second-order kinetics and the Langmuir isotherm model. The maximum adsorption capacity for fluoride was determined to be 122.27 mg/g. Additionally, factors that may affect the adsorption performance in practical applications, such as pH and competing ions, were also examined. Fourier-transform infrared and X-ray photoelectron spectroscopy analyses demonstrated that the nano MgO exhibited preferential adsorption of fluoride through specific inner-sphere complexation. The defluorination mechanisms of the nano MgO mainly included Mg2+-O defect, pore filling, ion exchange, and surface adsorption. The experimental findings unequivocally demonstrate the remarkable potential of the employed nano MgO in the efficacious removal of fluoride.