Burcu Erdoğan Alver

A comparative adsorption study of C2H4 and SO2 on clinoptilolite-rich tuff: Effect of acid treatment

In this study, ethylene (C2H4) and sulphur dioxide (SO2) adsorption properties of clinoptilolite tuff from Gördes, Turkey and that of acid treated forms were studied at 293K 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 2.0M HCl solutions at 70 °C during 3h. XRD, XRF, TG/DTG, DTA and N2 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).

The investigation of the effect of thermal treatment on bentonites from Turkey with Fourier transform infrared and solid state nuclear magnetic resonance spectroscopic methods.

There is a great deal of interest in the building industry in burned clays for production of building materials. Therefore, the effect of heat treatment on natural bentonite from Turkey was investigated by Fourier transform infrared (FT-IR) between the region of 4000-400cm(-1) and (29)Si, (27)Al magic angle spinning nuclear magnetic resonance (MAS NMR) measurement techniques at various temperatures between 200 and 700°C for 2h. The structural changes were also investigated upon heat treatment.

Ethylene Adsorption on Acid-Treated Clay Minerals

The adsorption of ethylene (C2H4) on five clay minerals (sepiolite, two kaolinites and two bentonites) and on forms treated with 1 M HCl solution (SH, K1H, K2H, B1H and B2H) was investigated. Adsorption isotherms for ethylene on all clay minerals were obtained at 4 °C and 20 °C up to 37 kPa. X-Ray diffraction (XRD), thermal analysis (TG/DTA) and N2 adsorption analysis were used for structural and thermal characterization. It was found that the extent to which ethylene gas was adsorbed by natural and acid-treated sepiolites (0.424–0.859 mmol/g) was higher than that exhibited by natural and acid-treated bentonites (0.068–0.144 mmol/g) and by kaolinites (0.014–0.061 mmol/g) at both temperatures. The uptake of ethylene on the acid-treated clays increased in the order K1H < K2H < B1H < B2H < SH.

Fourier Transform Infrared, Solid-State Nuclear Magnetic Resonance, and X-Ray Diffraction Studies of Natural and Acid-Treated Bentonites from Turkey

ABSTRACT The Fourier transform infrared (FT-IR) technique is widely used to distinguish structural properties and to derive information about structural changes following the chemical modification of clays in different conditions. Natural and acid-treated bentonites with HCl from Turkey were investigated by FT-IR between the region of 4000 and 400 cm−1 and the obtained results were supported by 29Si, 27Al magic angle spinning nuclear magnetic resonance (MAS NMR) and X-ray diffraction (XRD) measurement techniques. Effects of acid treatment were monitored by following the destruction of the original bentonite sample upon the acid treatment with different (6 hr, 12 hr, and 24 hr) acid exposure times. Following 24-hr acid treatment, the tetrahedral Si4+ structure was not fully collapsed but most of it turns into three-dimensional SiO2 impurity.

Adsorption of Sulphur Dioxide Using Natural and Modified Gördes Clinoptilolites

The adsorption of SO2 onto clinoptilolite-rich zeolite tuff from Gördes (Turkey) (natural-G) and its cation-exchanged (Na+, K+, Ca2+ and Mg2+) forms was investigated up to 100 kPa pressure at two different temperatures (273 K and 293 K). The structural properties of the clinoptilolites were studied by X-ray diffraction (XRD) and Fourier-transform infrared (FT-IR) spectroscopy. Quantitative XRD analysis showed that the major component of the natural-G sample was clinoptilolite, together with minor amounts of feldspar, opal-CT, smectite, mica-illite and amorphous material (opal-A). It was established that the uptake of SO2 onto the adsorbents increased in the order Ca-G < natural-G < Mg-G < K-G < Na-G at both temperatures.