Heavy metal removal using SnO_۲ nanoparticles prepared in a grape extract media

SnO۲ nanoparticles were first synthesized using a grape extract media, then characterized by XRD, FE-SEM, TEM, BET, and DLS techniques, and finally used as an efficient adsorbent for the removal of Pb۲+ and Cd۲+ ions from wastewater. The prepared sample had a tetragonal phase with an average crystallite size of ۴۱ nm (XRD analysis), a specific surface area of ۴۷.۰۸ m۲.g-۱ (BET method)/۴۶.۲۵ m۲.g-۱ (BJH method), and a pore diameter of ۶.۴۹ nm (BJH method). The best conditions for adsorbing were a ۳۰ ppm concentration of metal ions, ambient temperature, pH of ۶, and ۰.۰۲۵ g of an adsorbent. The maximum adsorption for Pb and Cd ions was ۹۷ and ۹۳%, respectively. The Elovich model was matched as the most suitable kinetic model, indicating that the adsorption mechanism is chemical adsorption. The negative values of ΔG (Pb: -۶.۳۸ kJ.mol-۱; Cd: -۴.۱۶ kJ.mol-۱) represent the spontaneousness of the adsorption process. The negative values of the parameters ΔH (Pb: -۶۳.۰ kJ.mol-۱; Cd: -۴۲.۹۵  kJ.mol-۱) and ΔS (Pb: -۱۸۸.۸ J.mol-۱; Cd: -۱۲۸.۴ J.mol-۱) represent the exothermic nature of the adsorption.

کلیدواژه ها:

Removal of heavy metals ، Kinetic and thermodynamic ، grape extract ، Wastewater ، SnO۲