The concentrations of Fe, Cu and Zn in selected wines from South-East Serbia

Fruits and vegetables constitute the cheapest source of essential trace elements for the majority of people living in developing countries. The Cu, Fe and Zn contents in twenty selected wine samples produced in the South-East region of Serbia were determined by flame atomic absorption spectrometry. The Cu concentrations varied from 0.07 to 0.57 ppm in wines, and the Fe concentrations fluctuated from 2.93 to 36.2 ppm, while the Zn levels were in the range from 0.21 to 0.67 ppm. The established contents of Cu and Zn showed that wines from this part of the world could serve as good dietary sources of the essential trace metals, and the determined values were within the allowed me¬tals levels in wines for human consumption

Electrochemical behaviour of serpentinite and forsterite in ferri/ferro cyanide benchmark redox system

Serpentinite rock collected near Kopaonik Mountain in Serbia is considered as a multiphase assemblage mostly consisting of mineral lizardite. Forsterite has been obtained by chemical-thermal treatment of grounded sample of serpentinite. Electrochemical features of these two materials were investigated by using modified carbon paste electrode (CPE) which included mixing analytes, graphite powder and parafin oil as a binder and packing the mixture in a Teflon holder. Morphological and structural characteristics of the samples were analyzed by SEM and XRD techniques which revealed presence of certain crystal phases and agregates of irregular shapes sized from 10 to 40 μm. Cyclic voltammetry was employed to study their electrochemical characteristics. The peak current height and peak-to-peak separation showed that the electrochemical reaction is quasi-reversible. Kinetic parameters were derived from Tafel analysis. Calculated kinetic parameters indicated prominent electrocatalytic effect of the minerals for ferri/ferro cyanide redox reaction in aquaeous solutionBook Of Abstracts of 4th Conference of The Serbian Society for Ceramic Material

Temperature imposed textural and surface synergism affecting the isomerization activity of sulfated zirconia catalysts

Using sulfuric acid as the sulfating agent, two catalyst series were obtained from hydroxide and nitrate precursor with a sulfate loading identical to commercial sulfated hydroxide, i.e., 4.2 mass %. After calcination at 500, 600 and 700 °C, all nine samples had various contents of residual sulfates depending on the origin of the catalyst. Accordingly, their surface properties were different, which, together with various textural properties, govern the formation of the active phase and their catalytic activity in the n-hexane isomerization reaction. The dominant activity and yield of mainly mono-branched isomers were attained in reaction at 200 °C with a commercially sulfated zirconia catalyst calcined at 500 °C. Among the SZ catalyst series synthesized from hydroxide and nitrate, the second according to its activity profile was similar to that of the commercially sulfated one, while samples originating from hydroxide showed some activity only after calcination at 600 °C. This is due to the poorer textural properties of the hydroxide series, necessitating a higher calcination temperature in order to promote the simultaneous decomposition of S-containing species and their re-adsorption into the zirconia matrix following interaction and active phase formation. It seems that the tetragonal zirconia phase was not responsible for the catalytic activity but a synergistic effect of the textural properties of the samples and the sulfate loadings, which determine different acid strengths on the catalyst surface

Examination of the structure and the photocatalytic behavior of nanostructure CoMoO4

Materials processing techniques, such as the combustion process, seem to hold much promise for the preparation of technologically important CoMoO4, owing to the control over stoichiometry, homogeneity and purity. Concerning the photocatalytic outness and powder characteristics, a glycine nitrate procedure (GNP) of CoMoO4 nanopowders by a glycine as a fuel and as a complexant was inspected. The synthesized samples were investigated by differential thermal analysis (DTA), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), UltravioletVisible (UV/Vis) spectroscopy and nitrogen adsorption method. The glycine nitrate procedure (GNP) is simple, effective and suitable method for controlling the composition and morphology of CoMoO4. A single-phase α and β crystalline form of CoMoO4 compound was confirmed by DTA and X-ray diffraction (XRD). The obtained CoMoO4 nanopowder showed tendency of agglomeration, inhomogeneous microstructure and plate-like crystals. The photocatalytic activity of CoMoO4 nanopowders was assessment by the photocatalytic degradation of crystal violet in aqueous solution. In addition, the obtained specific CoMoO4 nanopowder demonstrated acceptable specific surface area, which can be of particular importance for the photocatalytic processes. The photocatalytic testing of CoMoO4 nanopowders showed that these nanostructured materials can be promising solutions in photocatalytic processes toward green chemistry and sustainable development.X Serbian Ceramic Society Conference - Advanced Ceramics and Application : new frontiers in multifunctional material science and processing : program and the book of abstracts; September 26-27, 2022; Belgrad

Activating agricultural residues: Corn cob as a resource for adsorption-based pollution management

Program and book of abstracts / 2nd International Conference on Innovative Materials in Extreme Conditions i. e. (IMEC2024), 20-22 March 2024 Belgrade, Serbia

ELECTROPHORETIC DEPOSITION AS AN EFFECTIVE AND SIMPLE PROCESSING TECHNIQUE FOR FABRICATION OF MAGNESIUM SILICATE HYDRATE (M-S-H) COATINGS ONTO STAINLESS STEEL SUBSTRATES

Magnesium silicate hydrate (M-S-H) was prepared via one-pot hydrothermal synthesis and electrophoretically deposited (EPD) onto stainless steel substrate (Type 304), varying different process parameters. The optimal conditions for the EPD process were found to be as follows. A stable suspension of material was achieved using isopropanol containing 1% water as dispersing medium and Mg-nitrate as charging additive. The best coating was obtained after three successively repeated EPD processes at a voltage of 30 V, accompanied by drying at room temperature between each EPD cycle. The coating showed a thickness of 31 µm and very smooth surface. After calcination at 900 °C coating retains its adherence to the substrate but undergoes a structural transformation from poorly crystallized M-S-H to well-crystallized clinoenstatite phase which is known for its biocompatibility. As a result, it densifies and shrinks giving grainy and slightly rough surface. Structural properties and parameters of the magnesium silicate hydrate (M-S-H) and clinoenstatite were acquired by XRD technique, while morphology was examined by the analysis of SEM micrographs. This study demonstrates that: i) M-S-H can be synthesized through simple hydrothermal route starting from simple, low-cost precursors, ii) EPD process is an effective technique for deposition of M-S-H materials onto stainless steel and iii) inosilicate mineral (clinoenstatite) can be successfully obtained from M-S-H by calcination at 900 °C. HIGHLIGHTSMagnesium silicate hydrate (M-S-H) was prepared via a one-pot hydrothermal synthesis.The optimal conditions for the electrolytic deposition process were determined.Kinetics of the process were investigated using the Hamaker`s equation.Clinoenstatite can be successfully obtained from M-S-H by calcination

Removal of cationic dye from water by activated pine cones

Adsorption of a cationic phenothyazine dye methylene blueonto activated carbon prepared from pine cones was investigated with the variation in parameters of contact time, dye concentration and pH. The kinetic data were found to follow the pseudo-second-order kinetic modelclosely. The equilibrium data were best represented by the Langmuir isotherm with maximum adsorption capacity of 233.1 mg g-1. Adsorption was favored by using a higher solution pH. Textural analysis by nitrogen adsorption was used to determine specific surface area and pore structure of the obtained carbon. Boehm titrations revealed that carboxylic groups are present in the highest degree on the carbon surface. The results indicate that the presented method for activation of pine cones could yield activated carbon with significant porosity, developed surface reactivity and considerable adsorption affinity toward cationic dye methylene blue

Nanoemulsification synthesis route for obtaining highly efficient Ag3PO4 photocatalytic nanomaterial

Nanoemulsion technique based on Ouzo effect was applied for the fast and simple synthesis of Ag3PO4 at room temperature. X-ray powder diffraction analysis and Raman spectroscopy reviled that synthesized powder was single-phase. Using scanning electron microscopy analysis, it was found that the synthesized Ag3PO4 particles were near-spherical shape with an average diameter of 100 nm. The high value for the specific surface area of obtained powder was measured by Brunauer–Emmet–Teller method. Finally, the Ag3PO4 product was used as a photocatalyst for the photodegradation of crystal violet dye in an aqueous solution. Nanoemulsion strategy procedure provides a simple pathway to obtain a highly efficient single-phase Ag3PO4 photocatalyst

Investigation of Co0.9Ho0.1MoO4 Nanopowders Obtained by Glycine Nitrate Procedure

Nanometric size Co0.9Ho0.1MoO4 powder particles were obtained by applying glycine nitrate procedure (GNP). Powder properties have been studied by DTA, X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectra, Spectroscopy, Field emission scanning electron microscopy (FESEM), and nitrogen adsorption method. The photocatalytic activity of acquiring Co0.9Ho0.1MoO4 nanopowders was estimated by the photocatalytic degradation of crystal violet in an aqueous solution. We present a simple and effective method for controlling the composition and morphology of Co0.9Ho0.1MoO4, as well as a possible new approach in inorganic synthesis methodology. During photocatalytic testing, the studied nanoparticle powder indicated a potentially promising solution in photocatalytic processes toward green chemistry and sustainable development