Preparation and characterization of natural gum nanomuscovite nanocomposite for removal of heavy metals

Abstract A common technique to boost the adsorption capability of adsorbent material’s is to alter its composition. In this study, novel nanomuscovite / Arabic gum nanocomposite was synthesized to increase heavy metals adsorption capacity of nanomuscovite. The nanocomposite was fabricated using freeze-drying precipitation by loading gum Arabic (GA) on muscovite nanoparticle. Arabic gum particle was loaded into nanomuscovite with ratios 1:1, 2:1, and 1:2 by weight. The prepared nanocomposite was characterized using transmission electron microscopy (SEM), Fourier transform spectroscopy (FTIR), X-ray diffraction pattern (XRD), scanning electron microscopy (SEM), and BET specific surface area. The effects of various parameters (pH, solution temperature, composite dose, contact time, and metal concentrations) on adsorption capacity of Cd and Pb were studied. Four surface adsorption models were used, including Langmuir, Dubinin-Radushkevich, Temkin, and Freundlich models. The kinetics adsorption of Cd and Pb on the adsorbent surface was investigated using the pseudo first order, pseudo second order, intraparticle diffusion, and Elovich models. It was reported that nanocomposite prepared with a 2:1 w ratio of Arabic gum to nanomuscovite exhibited higher Cd and Pb removal than with the others. Additionally, the maximum Cd and Pb adsorption efficiencies (45.9, 38.01 mgg -1 , respectively) and high removal percentage (95% and 96%, respectively) were achieved at pH 7, 0.1 g adsorbent dosage, 75 ppm metal concentration, 25 °C solution temperature, and 60 min shaking time. The adsorption of these metals followed the Langmuir model, while the kinetics information fits a pseudo-second order. Thermodynamic calculation of Pb and Cd ion interactions indicate that the reaction is exothermic, as evidenced by the negative free energy ΔG° value, which suggests that the process occurs spontaneously.