Adsorption capacity of clinoptilolite for Zn2+ ions in alkaline solution

Abstract

The adsorption capacity of clinoptilolite for Zn²⁺ ions in alkaline solutions has been examined. It has been proved that in the alkaline solution the intrusion of Zn²⁺ ions into its structure depends on the metal ion concentration in the initial solution. Within 30 s of the reaction, ~78 % of Zn²⁺ ions were incorporated into the structure of clinoptilolite when the initial concentration of the solutions was 0.3 g Zn²⁺/dm³. The ion exchange reactions proceed more intensively in a solution with a 1.4 g Zn²⁺/dm³ concentration, because after 30 s of reaction ~96 % of Zn²⁺ ions are adsorbed. The variation of the pH value when using the alkaline solution was not considerable. Independently of the solution pH value, the cation exchange reactions are specific to the chemisorption process. X-ray diffraction and simultaneous thermal analysis results confirmed that the crystal structure of clinoptilolite remains stable.

DOI: http://dx.doi.org/10.5755/j01.ct.63.1.4527