Caliskan, NeclaKul, Ali RizaAlkan, SalihSogut, Eda GokirmakAlacabey, Ihsan2025-05-102025-05-1020110304-38941873-333610.1016/j.jhazmat.2011.06.0582-s2.0-80053259427https://doi.org/10.1016/j.jhazmat.2011.06.058https://hdl.handle.net/20.500.14720/1277Alacabey, Ihsan/0000-0002-3080-2296; Gokirmak Sogut, Eda/0000-0002-7707-3924The removal of Zn(II) ions from aqueous solution was studied using natural and MnO2 modified diatomite samples at different temperatures. The linear Langmuir, Freundlich and Dubinin-Radushkevich (D-R) adsorption equations were applied to describe the equilibrium isotherms. From the D-R model, the mean adsorption energy was calculated as >8 kJ mol(-1), indicating that the adsorption of Zn(II) onto diatomite and Mn-diatomite was physically carried out. In addition, the pseudo-first-order, pseudo-second-order and intraparticle diffusion models were used to determine the kinetic data. The experimental data were well fitted by the pseudo-second-order kinetic model. Thermodynamic parameters such as the enthalpy (Delta H-0), Gibbs' free energy (Delta G(0)) and entropy (Delta S-0) were calculated for natural and MnO2 modified diatomite. These values showed that the adsorption of Zn(II) ions onto diatomite samples was controlled by a physical mechanism and occurred spontaneously. (C) 2011 Elsevier B.V. All rights reserved.eninfo:eu-repo/semantics/closedAccessDiatomiteAdsorptionZincManganese OxidesKineticArticle193Q1Q1273621764214WOS:000296317500004