Sorption Properties of the Natural, K and Partially Deammoniated (H/NH 4 ) Forms of Clinoptilolite

A sample collected from the Aurangabad District, Maharashtra, India was characterized by XRD, IR, TG and DTA methods, and by chemical analysis, as a calcium-rich clinoptilolite. Two different methods involving exchange with KOH or NH 4 Cl led to the formation of K-clinoptilolite (K-Clino) and H/NH 4 -clinoptilolite (H/NH 4 -Clino). Water sorption studies were carried out on the parent clinoptilolite (P-Clino), K-Clino and H/NH 4 -Clino at five different temperatures in the range 303–423 K. Different adsorption models were applied to the data obtained from such sorption studies. Thermodynamic parameters such as the chemical potential were also computed from the sorption data and their significance is discussed.