Sorpcija herbicida na neorganski i organski modifikovanom prirodnom montmorionitu iz Bogovine

Efficiency of inorganic and organic modified montmorillonites from Bogovina for sorption of the S-metolachlor and clomazone was determined using batch adsorption method. Montmorillonite samples were pretreated with NaCl solution and then with different concentrations of organic complexes. Adsorption isotherms were measured by treatment of the samples with different concentrations of herbicide. Detailed mineralogical characterization of samples was performed using the X-ray diffraction method. Results of interaction between organic complexes and herbicides were obtained using X-ray diffraction, optical, thermal and spectroscopic analysis. Based on the results obtained using X-ray diffraction, it was concluded that all examined organic complexes and herbicides intercalated into interlayer space of montmorillonite. Montmorillonites modified with HDTMA complex exhibited monolayer, bilayer and pseudotrilayer arrangement of HDTMA+ cations in interlayer space, depending on degree of saturation. It has been found that the HDTMA+ cations are forming the partition phase for the herbicide on the surface of the montmorillonite. On the other hand, montmorillonite modified with PTMA complex exhibited monolayer arrangement of cations on the surface of montmorillonite in such a way that the cations act as pillars in interlayer space. The molecules of herbicides in this case were adsorbed on the surface of the montmorillonite. Which functional groups were involved in bonding processes between montmorillonite, organic complex and herbicide best describes infrared spectroscopy. High sorption of examined herbicides on some organic modified montmorillonites creates an opportunity for application of these substrates as potentially useful material for removal of S-metolachlor and clomazone from the environment.fikasnost prilikom sorpcije S-metolahlora i klomazona od strane neorganskih i organski modifikovanih montmorionita sa lokaliteta Bogovina odreĎena je metodom bach adsorpcije. Uzorci montmorionita su tretirani prvo rastvorom NaCl a zatim i različitim koncentracijama organskih kompleksa. Adsorpcione izoterme su dobijene tretiranjem uzoraka različitim koncentracijama herbicida. Detaljna mineraloška karakterizacija uzoraka uraĎena je metodom rendgenske difrakcije. Rezultati interakcije montmorionita sa organskim kompleksima i herbicidima dobijeni su primenom rendgenskih, optičkih, termičkih i spektroskopskih metoda. Na osnovu rezultata rendgenskih ispitivanja uzoraka, utvrĎeno je prisustvo organskih kompleksa i herbicida u meĎuslojnom prostoru montmorionita. Montmorioniti modifikovani sa HDTMA kompleksom pokazivali su jednoslojnu, dvoslojnu i pseudotroslojnu orijentaciju HDTMA+ katjona u meĎuslojnom prostoru. UtvrĎeno je da HDTMA+ katjoni formiraju particionu fazu na površini montmorionita, na kojoj dolazi do sorpcije molekula herbicida. Sa druge strane, montmorioniti modifikovani sa PTMA kompleksom pokazivali su jednoslojnu orijentaciju katjona na površini montmorionita i to na takav način da se katjoni ponašaju kao stubovi koji u zavisnosti od dimenzija dovode do širenja meĎuslojnog prostora. Molekuli herbicida se u tom slučaju vezuju za površinu montmorionita. Primenom metode infracrvene spektroskopije utvrĎeno je koje funkcionalne grupe učestvuju u interakciji izmeĎu montmorionita, organskih kompleksa i herbicida. Visoka sposobnost sorpcije odreĎenih uzoraka organski modifikovanih montmorionita otvara mogućnost njihove primene kao potencijalne sirovine za uklanjanje S-metolahlora i klomazona iz ţivotne sredine..

Characterization of clays from Slatina (Ub, Serbia) for potential uses in the ceramic industry

This study focuses on the mineralogical and thermal properties of clay from "Slatina" deposit, Ub, Serbia. Sampled clays were analysed by XRD, IR spectroscopy, ICP-OES, DTA, specific surface area (SSA), cationic exchange capacity (CEC), gravimetric and grain size measurements. Results show that the studied samples have a medium content of smectite-illite minerals with smaller amount of kaolinite together with quartz, feldspars and goethite. They consist generally of fine particles with medium to high plasticity. Based on their mineral composition and physical properties (grain size, plasticity, CEC) the clays are suitable as raw material for the ceramics industry

In vitro anticancer evaluation of novel triphenyltin(IV) compounds with some N-acetyl-S-naphthoquinonylcysteine derivatives

Triphenyltin(IV) compounds with naphthoquinone derivatives containing N-acetylcysteine, N-acetyl-S-(3,4-dihydro-3,4-dioxo-1-naphthyl)cysteine (1,2-NQC), 1, and N-acetyl-S-(1,4-dihydro-1,4-dioxo-2-naphthyl)cysteine (1,4-NQC), 2, were synthesized and characterized by elemental microanalysis, IR, multinuclear (H-1, C-13, Sn-119) NMR spectroscopy as well as HR-ESI mass spectrometry. With the aim of in vitro anticancer activity determination of ligand precursors and novel synthesized organotin(IV) compounds against human cervix adenocarcinoma (HeLa), human colon carcinoma (HT-29) and melanoma carcinoma cell line (B16F10), MTT colorimetric assay method was applied. The results indicate that synthesized compounds exhibited remarkable antiproliferative activity toward all tested cell lines with IC50 in the range from 0.17 to 0.87 mu M. Complex 1 showed the greatest activity against HT-29 cells, with IC50 value of 0.21 +/- 0.01 mu M, 119 times better than cisplatin, while complex 2 demonstrated the highest activity toward HeLa cells, IC50 = 0.17 +/- 0.01 mu M, which is similar to 26 times better than cisplatin

Design and In Vitro Biological Evaluation of a Novel Organotin(IV) Complex with 1-(4-Carboxyphenyl)-3-ethyl-3-methylpyrrolidine-2,5-dione

A novel triphenyltin(IV) compound with 1-(4-carboxyphenyl)-3-ethyl-3-methylpyrrolidine-2,5-dione was synthesized and characterized by IR, NMR spectroscopy, mass spectrometry, and elemental analysis. In vitro anticancer activity of ligand precursor and synthesized organotin(IV) compound was determined against tumor cell lines: human adenocarcinoma (HeLa), human myelogenous leukemia (K562), and human breast cancer (MDA-MB-453), using microculture tetrazolium test (MTT) assay. The results indicate that complex exhibited very high antiproliferative activity against all tested cell lines with IC50 values in the range of 0.22 to 0.53 mu M. The highest activity organotin(IV) compound expressed against the HeLa cells (IC50=0.22 +/- 0.04 mu M). The ligand precursor did not show anticancer activity (IC50>200 mu M). Furthermore, fluorescence microscopy analysis of HeLa cells reveal that organotin(IV) complex induced apoptosis as a mode of cell death, which is consistent with the increase of cells in the sub-G1 phase

Analiza sadržaja makro- i mikroelemenata u vodi za piće iz vodovodne mreže grada Požarevca

This study aims at analysing physical, chemical and microbiological properties, and content of macro- and microelements in the water from the Požarevac city public water supply system. Analysis shows an increased content of Ca in drinking water, as a result of the position of Požarevac on the sediments of river terrace of accumulative character of t1 type, predominantly consisting of quartzite. The water from the public water supply is alkaline ('calcic', 'bicarbonate water') and very hard, due to the increased Ca content. Beside Ca, potassium and aluminium exceed the maximum contaminant level, while Pb and Cd are at the very limit. Calculated data show that there are no short-term health risks regarding elements exceeding allowed concentrations found in the public water supply system. Data analysis regarding long-term health risks shows that Cd present in drinking water poses the only relevant threat to human health. Cancer risk is present in 202 out of 1000 inhabitants using this water.Predmet ispitivanja bila je voda za piće iz vodovodne mreže Grada Požarevca, sa aspekta fizičko-hemijske i mikrobiološke ispravnosti i prisustva makro- i mikroelemenata. Ispitivanja su ukazala na povećanu koncentraciju Ca u vodi za piće kao posledica položaja Požarevca na sedimentu rečne terase akumulativnog karaktera t1, koja je pretežno sagrađena od kvarcita. Kao posledica povećane koncentracije Ca, voda iz vodovodne mreže je alkalnog karaktera ('kalcijumova', 'biokarbonatna voda') i veoma tvrda. Osim Ca, K i Al prevazilaze maksimalno dozvoljene koncentracije, dok se Pb i Cd nalaze na samoj granici. Proračunati podaci pokazuju rizik od unošenja elemenata koji se u vodi iz vodovodne mreže Grada Požarevca nalaze u vrednosti višoj od dozvoljene pravilnikom, ni za jedan metal ne postoji kratkoročni zdravstveni rizik po zdravlje ljudi. Analiza podataka o dugoročnom zdravstvenom riziku ukazuje da jedina realna opasnost postoji od prisustva Cd u vodi za piće. Rizik od pojave kancera prisutan je kod 202 stanovnika od 1000 stanovnika koji koriste ovu vodu za piće

Agenda-setting for VET policy in the Western Balkans: employability versus social inclusion

For the last decade, the Western Balkan countries have sought to modernise their vocational education and training (VET) systems, adapting them to the needs of their emerging market economies. Within the framework of the EU accession process, the policy agenda for VET policies has been strongly influenced by a range of international and domestic policy entrepreneurs. This complex policy process has given rise to tension between policies that seek to frame the problem as one of employability and skill mismatch on the one hand and those that frame the problem as a challenge of social inclusion on the other. By examining the VET policy process in the Western Balkans, we show that national policies have been more strongly oriented towards the promotion of employability and the adaptation of VET systems to labour market needs, rather than to policies designed to overcome social exclusion and discrimination. Among the factors driving this economistic view of VET, we underscore the roles of various domestic and international policy entrepreneurs, including ministries in charge of education, employment and social policy, social partners, the European Commission, and bilateral and multilateral donors. We conclude that increased cooperation is needed between international and domestic policy entrepreneurs who favour inclusive education systems in order to place social inclusion higher up on the VET policy agenda

Characterisation of Purified Gypsum and Insoluble Impurities Obtained from Phosphogypsum Waste

In this study, the chemical and phase composition of two samples of phosphogypsum from the waste dumps of the Industry of Chemical Products "Elixir - Prahovo" (Serbia) were examined, as well as the possibility of recrystallization of gypsum from an aqueous suspension of phosphogypsum. 'the negative effect of higher temperatures on the solubility of calcium sulfate (13.08 mmol/dm(3) at 95 degrees C vs. 15.43 mmol/dm(3) at 40 degrees C) was utilized. In several repeated cycles, calcium sulfate component was progressively dissolved in water at room temperature and then precipitated at 100 degrees C, using the same liquid phase throughout the experiment. Therefore, phosphogypsum was separated into recrystallized (purified) gypsum, insoluble residue and supernatant, and the mass balance for the experiment was calculated. Elemental, XRD and SEM-EDS analyses were performed on raw phosphogypsum, purified gypsum and insoluble residue. The whiteness of raw phosphogypsum and purified gypsum were determined and compared. The main objective of the study was to investigate the nature of insoluble impurities, in order to define and optimize the methods for their removal during a potential industrial processing of phosphogypsum

Mineralogical study of clays from Dobrodo, Serbia, for use in ceramics

This study focuses on the mineralogical characterization of four raw clay samples from Dobrodo deposit, Serbia. Several analytical methods were applied to determine the chemical and mineralogical composition, morphology and physical properties (colour, plasticity, specific surface area, particle size and cation-exchange capacity) of the clay samples. Kaolinite, smectite and illite are the predominant phases in all of the samples studied that contain between 60.2 and 87.1 wt.% of clay. Quartz, feldspars, paragonite and Ti- and Fe-bearing phases were also identified. The relatively high SiO2/Al2O3 mass ratio indicates abundant quartz. The cation-exchange capacity of the samples varied between low and moderately charged clay minerals (12-52 mmol 100 g(-1)) with specific surface area values ranging from 94 to 410 m(2) g(-1). The plasticity index values (11-23%) suggest low to moderate plasticity. Preliminary results show that most of the raw clay from Dobrodo deposit might be suitable for use in ceramic applications

Thermal investigation of acetochlor adsorption on inorganic- and organic-modified montmorillonite

Results presented in this paper are pioneering attempt toward better understanding of the thermal stability of acetochlor sorption in inorganic and organic montmorillonites. Changes in surface properties of acetochlor adsorbed on montmorillonites and montmorillonites modified with hexadecyltrimethylammonium bromide have been investigated by thermogravimetry, derivative thermogravimetry and infrared spectroscopy. The mass loss, as a result of the heating treatment, indicates release of free water, transformation of hydrophilic to hydrophobic surface, the release of acetochlor sorbed on the montmorillonite, the release of acetochlor sorbed on the montmorillonite and dehydroxylation of the structural OH units

Refinement of waste phosphogypsum from Prahovo, Serbia: characterization and assessment of application in civil engineering

Two samples collected from the phosphogypsum deposits of the chemical products industry Elixir Prahovo (Serbia) were subjected to a recrystallization experiment performed over several repeated cycles. In these tests, phosphogypsum was separated into recrystallized (purified) gypsum, insoluble residue and supernatant. Both raw phosphogypsum and recrystallized gypsum were examined using inductively coupled plasma optical emission spectrometry, X-ray diffraction and scanning electron microscopy with energy-dispersive spectrometry. The activity concentrations of (238)u, (235)u, Ra-226, Pb-210,Th- 232 and 40 K were investigated using gamma-ray spectrometry. Based on the activity concentration results, a number of radiometric parameters were calculated for the original and recrystallized phosphogypsum (i.e. radium equivalent activity, y indices for construction materials, a index and external and internal hazard indices). Raw phosphogypsum samples showed greater mean activity concentration levels of U-238 and Ra-226 than the international recommended limits, while the recrystallized gypsum demonstrated notably lower activity concentrations for these two isotopes. The activity concentration of Ra-226 in recrystallized gypsum is similar to 6 times lower than in raw phosphogypsum. Therefore, recrystallized gypsum does not present a radiation hazard when used as a building material, while raw phosphogypsum meets the requirements only for road construction materials