Influence of the exchangeable cations on SO2 adsorption capacities of clinoptilolite-rich natural zeolite

The sulfur dioxide adsorption on clinoptilolite-rich tuff from Bigadic region of Western of Turkey and its modified forms (Na+, K+, Ca2+ and Mg2+) have been studied at 273 K and 293 K up to 100 kPa. The structural properties of clinoptilolites were studied by X-ray diffraction (XRD) and Fourier transform infrared (FT-IR). The quantitative XRD analysis demonstrated that the Natural-B sample is mainly constituted by clinoptilolite (80–85%) with minor contents of quartz (7–8%), feldspar (5–6%) and mica-illit (4–5%). It was found out that the adsorption capacity and the affinity of SO2 with clinoptilolite samples depended mainly on the type of exchanged cations and decreased as Na-B > K-B > Mg-B > Natural-B > Ca-B for both temperature. These results show that clinoptilolite-rich zeolites are considered potentially good adsorbents for SO2 removal.