Abstract

Fluoride (F) in high concentration is very hazardous to human health. The efficacy of nickel oxide nanoparticles (NiO NPs) was investigated in this research as an adsorbent for the elimination of fluoride from aqueous solutions. The effects of pH, contact time, initial concentration of F, and adsorbent dosage on the performance of NiO NPs in the removal of fluoride from aqueous solutions were investigated at room temperature. Langmuir, Freundlich, Temkin, Koble-Corrigan, and Redlich-Peterson adsorption isotherms were employed for the analysis of the adsorption process. Maximum adsorption was achieved at 60 min at pH 5, an adsorbent dosage of 0.02 g/L, and an initial fluoride concentration of 20 mg/L. The results also showed that fluoride adsorption by NiO NPs was more compatible with the Freundlich isotherm (R-2 = 0.999). and that the process followed the pseudo-second-order kinetic, Ho (type I) (R-2 = 0.9999 and R-2 = 0.9997 at 20 and 25 mg/L fluoride concentrations, respectively). From the results obtained, it can be concluded that NiO NPs can be used with high efficiency for fluoride removal.