Improvement of montmorillonite adsorption capacity for lead ions by modifying with hexadecyl trimethyl ammonium chloride: Characterization, modelling and optimization studies

Abstract

Heavy metal pollutants, particularly Pb are considered as critical contaminants causing harmful health risks for a human. In this study, montmorillonite modified with hexadecyl trimethyl ammonium chloride surfactant (N-HTAC) was applied as a new adsorbent for the Pb+2 adsorption from aqueous solutions. The N-HTAC was characterized by the scanning electron microscopy, x-ray diffraction, energy-dispersive x-ray spectroscopy, and Brunauer-Emmett-Teller. The central composite design using R software was chosen for modelling the effect of operating parameters. Based on the findings obtained from the analysis of variance, reduced full second-order model with multiple R2, 0.94, adjusted R2, 0.93, and LoF, 0.96, was represented satisfactory adjustment with experimental data. The Solver “add-ins” was employed to gain the optimum conditions for the modelling. The optimum operating points giving the maximum Pb+2 removal (99.99%), were found to be initial Pb+2 concentration: 0.1 mg L1− adsorbent dosage: 4.33 g L-1, HTAC dosage: 4.19 g L-1, pH: 7.13, temperature: 28.06ºC, and the reaction time: 103.4 min. The findings of the study showed that by enhancing and improving natural adsorbents, a significant amount of environmental pollutants can be eliminated. • In this study, a new modified adsorbent (N-HTAC) was used to remove lead ions. • The results of this study showed that the N-HTAC used has high efficiency (99.99%) in the removal of lead. • The results of this study and the data obtained can be used to supplement the information on the removal of contaminants with adsorbents. Method name: Montmorillonite modified with hexadecyl trimethyl ammonium chloride surfactant (N-HTAC) was applied as a new adsorbent for the adsorption of Pb (II) ions, Keywords: Nano clay, Hexadecyl trimethyl ammonium chloride, Pb (II), Modeling, Response surface methodology, Optimization