Application of Response Surface Methodology to Optimize Removal Efficiency of Fluoride by Ionic Liquid Modified Magnetic Activated Carbon Nanocomposite From Aqueous Solution

Fluoride in high concentrations is hazardous and a threat to human life. This study used response surface methodology (RSM) to remove fluoride using ionic liquid-modified magnetic activated carbon (IL@mAC) nanocomposite and optimized the process parameters. The IL@mAC nanocomposite was synthesized by Fourier transform infrared spectroscopy (FTIR) and X-ray powder diffraction (XRD), and its adsorption efficiency for removal of fluoride was investigated under different operational such as pH (2-8), contact time (15-100 minutes), initial concentration (10-50 mg/L), and IL@mAC composite (0.01-0.1 g) at room temperature. The equilibrium experiment showed that the highest removal efficiency (~88%) was obtained at pH 5, the initial concentration of adsorbent of 0.1 mg/L, the initial concentration of fluoride of 50 mg/L, and the processing time of 15 minutes. The findings indicated high correlation coefficients for the proposed model (adjusted R2=0.9527 and R2=0.8048). Furthermore, the pseudo-second-order kinetic model was ideal (R2=0.998). The current study suggested that the adsorption process optimized by effective operational factors is highly efficient for fluoride removal.