In this study, ethylene (C2H4) and sulphur dioxide (SO2) adsorption properties of clinoptilolite tuff from Gordes, Turkey and that of acid treated forms were studied at 293 K using volumetric apparatus up to 38 and 100 kPa, respectively. In order to consider the effect of acid treatment on structural and gas adsorption properties of zeolite, clinoptilolite mineral was modified with 0.1, 0.5, 1.0 and 2.0 M HCl solutions at 70 degrees C during 3 h. XRD, XRF, TG/DTG, DTA and N-2 adsorption methods were employed for thermal and structural characterization of clinoptilolite samples before and after the acid treatment. SO2 adsorption capacities (2.356-2.739 mmol/g) of the clinoptilolite samples were superior to those of the C2H4 adsorptions (0.619-1.219 mmol/g). (C) 2013 Elsevier B.V. All rights reserved.