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Belgrade, Serbia

Sakan S.M.,IChTM | Dordevic D.S.,IChTM | Trifunovic S.S.,University of Belgrade
Polish Journal of Environmental Studies | Year: 2011

The contamination levels of V, Cr, Ni, Cu, Zn, Cd, and Pb in canal sediments (Danube alluvial formation) were assessed to evaluate environmental quality and potential contamination. Results indicate that silicates and oxides (Fe and Mn) are important for binding investigated elements (Cr, Zn, Cd, Ni, V Pb, and Cu). The values of calculated enrichment factors indicate that the investigated locations includes minor to moderate enrichment of sediment with Cr, V, Cu, Pb, Cd, Ni, and Zn, except for one location where sediment is severely enriched with Zn. Factor analysis shows two main anthropogenic sources: - Cr, Zn, Cd, Ni, V, and Pb are mainly derived from industrial sources and, - Cu and Pb are mainly derived from other local contamination sources combined with traffic sources. With increasing distance from the Refinery, the anthropogenic impacts of the metal content were lower and geochemical control of the contents of the element became dominât, which indicate the influence of the refinery on the metal pollution in the sediments.

Sakan S.M.,IChTM | Dordevic D.S.,IChTM | Manojlovic D.D.,University of Belgrade
Environmental Monitoring and Assessment | Year: 2010

The purpose of this study was to examine the levels of trace elements and to discuss the origin and mobility of these contaminants in the canal sediments (alluvial formation of the Danube River). The most significant fractions binding all of the studied elements were oxides and silicates. The high proportion of elements in the residual fraction and the generally low contents of extractable elements reflected the background geochemical conditions. The contents of trace elements (except Hg and As) were dominantly controlled by the presence of Fe and Mn oxides as well as by the grain size and the geochemical composition of the sediment. The studied alluvial sediments were not heavily contaminated; there were only few sites where an anthropogenic influence on the concentrations of some metals (Cu, Cd, Zn, and Pb) was noticed. The results from this study show that impact of Pančevo industrial zone on the quality of the Danube River and its contamination with trace element is minor. © Springer Science + Business Media B.V. 2009.

Sakan S.M.,IChTM | Dorevic D.S.,IChTM
Journal of Environmental Science and Health - Part A Toxic/Hazardous Substances and Environmental Engineering | Year: 2010

This paper describes an approach for the evaluation of metal contamination in sediment, using the determination of binding forms of elements (sequential extraction method), the total element content (digestion method), as well as a comparison of the obtained results with the legislative limits of the EU. Results indicate that silicates are significant substrates for Ni and Cr, whereas Zn, Cd, Pb, and Cu were not dominantly bound to silicates. Mg is present in the form of carbonates and silicates; Fe is in the form of oxides, and Mn is in the form of Mn carbonate and oxides. Zn, Cd, and Cu are dominantly extracted in the labile fractions and because of this they are likely to pose a direct and significant threat to the environment. The results of a comparison with the legislative limits of the EU indicated that in some of the sediments, elevated levels of Zn, Cd, and Cu exist. The contamination was caused by permanent pollution, originating mainly from industrial activities, municipal sewage discharge and agriculture. Results indicate to the significance of the employment both of methods, sequential extraction and total digestion, for metal investigation in sediment. With the aim of protecting the sediment quality of the Tisa River, of importance for Central Europe, the obtained results also indicate the necessity for systematic investigations in all countries through which this river flows. Copyright © Taylor & Francis Group, LLC.

Atanasova G.,Bulgarian Academy of Science | Guergova D.,Bulgarian Academy of Science | Stoychev D.,Bulgarian Academy of Science | Radic N.,IChTM | And 2 more authors.
Solid State Phenomena | Year: 2010

In the present work, the surface properties of various Al oxide films were investigated. The oxide films were produced on a stainless steel by spray pyrolysis and cathodic deposition methods. The films obtained represent typical layers that can be used as a support in model systems to investigate alumina-based catalysts. Information about the chemical environment of the Al and O ions in the oxide films depending on the preparation conditions has been deduced from the binding energies of the Al 2p and O ls electron core levels and corresponding Auger parameters. © (2010) Trans Tech Publications.

Jacimovski D.R.,IChTM | Garic-Grulovic R.V.,IChTM | Grbavcic Z.B.,University of Belgrade | Duris M.M.,IChTM | Boskovic-Vragolovic N.M.,University of Belgrade
Hemijska Industrija | Year: 2014

Wall-to-bed momentum, heat and mass transfer in the vertical liquid-solids flow, as well as in the single phase flow, were studied. The aim of this investigation was to establish the analogy among those phenomena. Also, effect of particle concentration on momentum, heat and mass transfer was studied. The experiments in hydraulic transport were performed in 25.4 mm I.D. cooper tube equipped with a steam jacket, using spherical glass particles of 1.94 mm in diameter and water as a transport fluid. The segment of the transport tube used for mass transfer measurements had internal coating made of benzoic acid. In the hydraulic transport two characteristic flow regimes were observed: turbulent and parallel particle flow regime. The transition between two characteristic regimes (γ* = 0), occurs at a critical voidage ε ≈ 0.85. The vertical two-phase flow was considered as the pseudofluid, and modified mixture-wall friction coefficient (fw) and modified mixture Reynolds number (Rem) were introduced for system characterization. Experimental data show that the wall-to-bed momentum, heat and mass transfer coefficients, in vertical flow of pseudofluid, for the turbulent regime are significantly higher than in parallel regime. Wall-to-bed, mass and heat transfer coefficients in hydraulic transport of particles were much higher than in singlephase flow for lower Reynolds numbers (Re < 15000), while for high Reynolds numbers (Re > 15000), there was not significant difference. The experimental data for wall-to-bed momentum, heat and mass transfer in vertical flow of pseudofluid in parallel particle flow regime, verify analogy among these three phenomena.

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