▎ 摘 要
In this study, the adsorption property of 3.0 generations polyamidoamine dendrimer functionalized magnetic graphene oxide (MGO-PAMAM-G3.0) for Ag(I) in aqueous solution was investigated by batch experiments and magnetic separation technology. The adsorption mechanism was studied by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR) and N-2 adsorption/desorption isotherm. The effect of the adsorption conditions, such as pH, initial Ag(I) concentration, contact time and temperature on the adsorption property of MGO-PAMAM-G3.0 for Ag(I) was explored. The equilibrium data were analyzed using the Henry, Langmuir, Freundlich and Temkin isotherm models. The pseudo-first-order and pseudo-second-order adsorption kinetic models were employed to fit kinetics experimental data. The results showed that the main adsorption mechanism of MGO-PAMAM-G3.0 for Ag(I) was the formation of N-metal ions chemical complex and Ag(I) was reduced to element Ag in the adsorption process. The solution pH value had a major impact on adsorption Ag(I) with optimal removal observed around pH = 4.0-6.0 and the MGO-PAMAM-G3.0 was suitable for the adsorption low concentration Ag(I) from aqueous solution. The experimental data were better fitting of the Langmuir isotherm model and the pseudo-second-order equation, respectively.