Ljiljana Damjanović

The adsorption of nicotine from aqueous solutions on different zeolite structures

The present work is focused on the adsorption of nicotine from aqueous solutions. Based on the data available in the literature, serious concern is claimed regarding the appearance of nicotine in ground, surface and municipal wastewaters. In order to investigate the possibility of abatement by adsorption, three different types of zeolites (BEA, MFI and HEU) have been applied as adsorbents. In addition, the adsorption was performed on activated carbon, a solid customarily used for removal of pollutants from water. The adsorption of nicotine was studied by isothermal microcalorimetry, which provided the heats evolved as a result of adsorption. The values of these heats revealed that the investigated solids are energetically heterogeneous for the adsorption of nicotine from aqueous solution. Additionally, the amounts of adsorbed pollutant were determined and presented in the form of adsorption isotherms. The obtained adsorption isotherms were interpreted using Langmuir, Freundlich, and Sips equations; the latter was found to express high level of agreement with experimental data of nicotine adsorption on the investigated solids. The possibilities to regenerate the adsorbents were examined by means of thermogravimetry coupled with mass spectrometry. From all obtained results, it was possible to distinguish zeolite BEA as a material which possesses the capacity for adsorption of nicotine comparable to that of activated carbon.

Determination of Acid/Base Properties by Temperature Programmed Desorption (TPD) and Adsorption Calorimetry

The characterization of the acidity of zeolites and related materials is of great importance for applications of these materials, particularly in the petrochemical industry and environmental sciences. This chapter provides a comparison of the two most widely used techniques for the study of acid/base properties of zeolites, namely temperature-programmed desorption and adsorption calorimetry. The information needed to perform and interpret these experiments as well as advantages and limitations of these methods are summarized. The curves and data obtained for the two most studied zeolites Y and ZSM-5 are discussed, which can be particularly useful for young researchers in this field.

Temperature-Programmed Desorption (TPD) Methods

This chapter presents the fundamentals, the experimental setups and the applications of temperature-programmed desorption (TPD), method used to investigate the events that take place at the surface of solid material while its temperature is changed in a controlled manner. At the beginning, fundamental principles of adsorption and desorption phenomena, as well as the data concerning first experimental setups are given. Further, important information related to the construction of nowadays used equipment and the organization of common experiments are underlined. The significance of data directly obtained from temperature-programmed experiment—TPD profile, which are the area under it and the position of peak maximum, are highlighted. Particular attention is given to the results that can be derived from these data—characterization of active sites that can be found on the surface of solid material and determination of kinetic and thermodynamic parameters of desorption process. In this regard, the influence of important experimental parameters on derived values is explained. Besides, the distinctions between TPD experiments performed in ultra-high vacuum and in the flow systems (differences in experimental setups and in the derivation of kinetic and thermodynamic parameters) are explained. Also, the modification of temperature-programmed techniques, known as temperature-programmed oxidation and temperature-programmed reduction are shortly explained and compared with temperature-programmed desorption method. In the end, a brief comparison of the TPD and adsorption calorimetry, two most widely used techniques for the study of acid/base properties of catalysts, is given.

Spectroscopic study of an icon painted on wooden panel

Russian icon painted on wooden panel analyzed in this work is interesting for art historians because there is no precise information in which workshops it was made or who the author was. Similar icons are often found in churches and monasteries in our region. In order to obtain information about materials used for creation of investigated icon two micro-analytical techniques were used: Energy-Dispersive X-Ray Fluorescence spectroscopy (EDXRF) and micro-Raman spectroscopy. Obtained results confirmed presence of following materials: lead-white, vermilion, minium, ultramarine, brown and green earth pigments and silver in combination with yellow organic varnish, which served to an iconographer for gilding. Ground layer was made of calcite. Blue pigment ultramarine was probably used for blue colour as well as for obtaining particulars hues in several parts of the paint layer. This can be important information for further research concerning particular workshop in which the icon was made. Identified materials are typical for Russian iconography of the 19th century. [Projekat Ministarstva nauke Republike Srbije, br. OI 177021 i OI 177012]