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β-Zeolite was synthesized and modified with ethylenediamine (EDA). The synthesized materials were characterized and used for the removal of nickel(II) from aqueous solutions. The influences of the pH, contact time, and temperature on nickel(II) adsorption onto synthesized β-zeolite and β-zeolite modified with ethylenediamine (β-zeolite–EDA) were studied by a batch technique, and X-ray photoelectron spectroscopy was employed to analyze the experimental data and identify the formation of coordination bonds between the adsorbents and nickel(II). The dynamic process showed that the adsorption of nickel(II) onto β-zeolite and β-zeolite–EDA matched the pseudo-second-order kinetics model, and the adsorption of nickel(II) was significantly dependent on the pH values. Through simulation of the adsorption isotherms by the Langmuir, Freundlich, and Dubinin–Radushkevich models, it could be seen that the adsorption patterns of nickel(II) onto β-zeolite and β-zeolite–EDA were mainly controlled by surface complexation a...

Succinamic acid-functionalized nanosilica (SA@SiO2) was synthesized, characterized, and tested for hexavalent uranium preconcentration from contaminated aqueous solutions. The succinamic acid grafted nanosilica exhibited improved uranium preconcentration capacity in comparison with that of raw nanosilica. The effects of environmental conditions such as pH, ionic strength, solid concentration, foreign ions, and temperature on uranium(VI) preconcentration performance were investigated by batch technique in detail, and the related mechanism is discussed with the aid of X-ray photoelectron spectroscopy. Results showed that U(VI) preconcentration by SA@SiO2 was strongly dependent on pH while less dependent on ionic strength; the preconcentration was mainly dominated by inner-sphere surface complexation. The coexisting cations had no effects, while anions influenced U(VI) preconcentration significantly. The preconcentration of U(VI) was favorable at lower temperatures; the maximum preconcentration capacity was ...