Application of β-Zeolite, Zeolite Y, and Mordenite as Adsorbents to Remove Mercury from Aqueous Solutions

In the present study, adsorption capacity of mercury(II) on β-zeolite, zeolite Y, and mordenite is investigated. It has been observed that removal rate of Hg(II) is better with zeolite Y than β-zeolite and mordenite, whereas, adsorption capacity of β-zeolite is found to be more than that of zeolite Y and mordenite. Five equilibrium isotherms have been tested to fit the adsorption data. The kinetic data are analyzed using the pseudo-first order, pseudo-second order, and diffusion models. The Freundlich isotherm model shows better fit for β-zeolite and zeolite Y, whereas, in the case of mordenite, Temkin isotherm fits the data well. The kinetic data of adsorption of Hg(II) on β-zeolite, zeolite Y, and mordenite fit well with pseudo-second order. Diffusion studies show that the adsorption of mercury on β-zeolite and zeolite Y are intraparticle diffusion controlled, and mordenite is film-diffusion controlled.