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Dive into the research topics where Dubravka Relić is active.

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Featured researches published by Dubravka Relić.


Journal of Hazardous Materials | 2011

Aqua regia extracted metals in sediments from the industrial area and surroundings of Pančevo, Serbia.

Dubravka Relić; Dragana Đorđević; Sanja Sakan; Ivan Anđelković; Srđan Miletić; Jelena Đuričić

Surface and buried sediments were analyzed for Ba, Ca, Cd, Co, Cr, Cu, Mn, Ni, Pb, Zn and V, as well as for total carbon and hydrogen to assess the distribution of sediment pollution due to the vicinity of the petrochemical complex. The samples, collected from 20 locations within the petrochemical complex and from 16 locations outside the complex, were aqua regia extracted and analyzed by ICP/OES. Metals were determined with an acceptable accuracy for certified metals of 82-113%. The precision for the aqua regia extraction was satisfactory, less than 20%, except for Cd where it was 28%. Comparison of the data from the petrochemical with those from the non-petrochemical areas showed different distributions of the metals. Metals that exceeded the baseline range; Ba, Cd, Cu, Zn and Pb, were detected in higher concentrations in sediments that were under the influence of the chlor-alkali plant within the petrochemical complex. Comparison with data from the petrochemical complex and its surroundings and their distribution demonstrated that the metal compositions of the sediments were modified by anthropogenic activities.


Environmental Geochemistry and Health | 2015

Evaluation of sediment contamination with heavy metals: the importance of determining appropriate background content and suitable element for normalization

Sanja Sakan; Gordana Dević; Dubravka Relić; Ivan Anđelković; Nenad Sakan; Dragana Đorđević

In the present study, concentrations of heavy metals (Cd, Cu, Co, Mn, Cr, Ni, Pb, and Zn) were determined at 35 river sediments in Serbia. The anthropogenic heavy metals input and quantification of the metal enrichment degree in sediments were estimated by calculating geo-accumulation indices (Igeo) and enrichment factors (EF). These pollution indices have been calculated using different background values (continental crust and local background values) and different element used for normalization (Al and Fe), followed by result comparison. The EF values calculated with continental crust as background (minor to extremely severe enrichment) were higher than when regional background values were used (minor to moderate enrichment). Significant influence of background values on the Igeo values is observed. Values of geo-accumulation index (<2) revealed that studied river sediments are remaining unpolluted to moderately polluted with Co, Mn, Cr, and Ni. Significant pollution in the sediments was observed for Cd, Cu, Pb, and Zn elements. The results of this study confirm the relevance of precise and accurate determining of local background concentrations while assessing sediment pollution. The values of EFs for studied elements were more influenced by the choice of background values than selection of element used for normalization. Our recommendation would be to use the local and regional background content in quantification of metal contamination in sediments, since these values differ and are site and region dependent.


Environmental Earth Sciences | 2015

Risk assessment of trace element contamination in river sediments in Serbia using pollution indices and statistical methods: a pilot study

Sanja Sakan; Gordana Dević; Dubravka Relić; Ivan Anđelković; Nenad Sakan; Dragana Đorđević

To effectively manage potential environmental and human health impacts of contaminated river sediments, it is important that information about the source (anthropogenic vs geogenic), variability and environmental risks associated with the contamination are well understood. The present study was carried out to assess the source and severity of contamination and to undertake a risk assessment for selected elements (As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, V and Zn) in river sediments in Serbia. The estimate of the anthropogenic component of contamination was derived by determining the total element content and the background values for elements in sediments, and the severity of pollution was assessed by calculating a number of pollution indices including the contamination factor, the enrichment factor, the index of geoaccumulation, the ecological risk factor, the potential ecological risk index, the pollution load index, the combined pollution index, the modified degree of contamination and the toxic unit factor. This analysis indicates that river sediments in Serbia are primarily polluted with Zn, Cu and Cd. The most contaminated river systems are the Ibar, Pek, West Morava and Great Morava rivers. Mining activities were found to have a significant influence on sediment. Multivariate analyses suggested anthropogenic origins for Pb, Zn, Cd, As, Ni and Cu, whilst Fe, V, Mn, Co and Cr appear to have a mixed origin (both lithogenic and anthropogenic sources). A geochemical approach, with a calculation of pollution indices and statistical methods, is recognised as useful for the risk management of trace elements in sediments around the world.


Energy Sources Part A-recovery Utilization and Environmental Effects | 2011

Speciation of Trace and Major Elements from Coal Combustion Products of Serbian Power Plants (I)—“Kostolac A” Power Plant

Aleksandar Popovic; Dragana Djordjevic; Dubravka Relić; A. Mihajlidi-Zelić

Abstract In order to examine association patterns and pollution potential of trace and major elements from coal ash, six composite samples of fresh, filter fly, and aged dump coal ash from “Kostolac A” power plant located 100 km from Belgrade, the Serbian capital, were subjected to the sequential extraction procedure. Five extractants were applied (in the following order): distilled water, 1 M ammonium acetate, 0.2 M ammonium oxalate/0.2 M oxalic acid, an acidic solution of H2O2, and 6 M HCl. Obtained concentrations were statistically analyzed and associations of trace and major elements were established.


Central European Journal of Chemistry | 2014

Water-soluble inorganic ions in urban aerosols of the continental part of Balkans (Belgrade) during the summer - autumn (2008)

A. Mihajlidi-Zelić; Dragana Đorđević; Dubravka Relić; Ivana Tošić; Ljubiša M. Ignjatović; Maria A. Stortini; Andrea Gambaro

Abstract Size-segregated aerosol samples were collected using six stages High Volume Cascade Impactor. Aerosol mass and water soluble ions concentrations were determined. The Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model was used to study the origin of air masses arriving to Belgrade in the investigated period. The obtained results of aerosol mass and water-soluble ion concentrations have been divided into six sub-data sets based on air mass categories. The highest average mass concentration of the fine mode (Dp ≤ 0.49 μm) was found for air masses coming to Belgrade from the southeast and northwest directions, and of the coarse mode (3.0 < Dp ≤7.2 μm) for air masses arriving from the northwest direction. The highest concentrations of SO42– were found in the fine particles transported to the investigated area by air masses from southeast direction. The analysis of contribution of marine aerosol components (Na+ and Cl-), the Correlation and Cluster Analysis indicated the influence of marine aerosol on urban aerosol of the central Balkans coming from the Western Mediterranean and northern direction. NH4+ and SO42- and K+ dominated in the fine mode for all air mass categories. PCA demonstrated the dominant impact of secondary aerosol formation processes on urban aerosols. Graphical Abstract


Energy Sources Part A-recovery Utilization and Environmental Effects | 2015

Trace and Major Elements in Ash of “Nikola Tesla A” Power Plant (III)—Associations of Elements in Passive Cassette Ash

Aleksandar Popovic; Dubravka Relić; Dragana Djordjevic

Statistical analysis of concentrations of trace and major elements obtained by five-step sequential extraction of samples of dump ash taken from a passive, previously filled cassette of “Nikola Tesla A” power plant dump located near Belgrade, Serbia, revealed the existence of magnesium alumosilicates, mixed silicates of potassium and magnesium, alumosilicates not containing magnesium, and compounds of aluminium, not containing silicon or magnesium that were dissolved in the fifth phase of extraction. Intraphase associations of major elements dissolved in the third phase were not established. Preferential intraphase and interphase binding of matrix and adsorbed and ion-exchangeable fractions of elements were established and discussed.


Archive | 2009

Speciation of Heavy Metals in Geological Matter of the Serbian National Parks, Protected Areas and Cities Within the Danube River Basin After the War Conflict in 1999

Aleksandar Popovic; Dragana Djordjevic; Dubravka Relić; Zorka Vukmirović; A. Mihajlidi-Zelić; Predrag Polić

In order to assess the effects of the 1999 NATO bombing of Serbia on the environment, some of the most widespread and feared pollutants, including heavy metals were determined in various sediment samples that were taken from three areas hit by bombing and were previously well-known for its unpolluted environment. Samples of soil and sediments from Fruska Gora National Park as well as Deliblatska Pescara and Zasavica Protected Areas which all lie in the immediate vicinity of the Danube, were investigated by sequential extraction, in order to determine potential substrates of heavy metals and to predict their potential mobilization mechanisms into the environment, especially into surface and ground water flows. This was important because the Danube, one of Europes most important rivers, flows in the immediate vicinity of the National Park and Protected Areas and any contamination could cause severe effects on the rivers ecological status and unpredictable consequences on the countries downstream, including the ecology of the Black Sea. Results show that all three examined areas are polluted with cadmium, the main source of which is projectiles (i.e. their explosions which could contaminate the examined sediments). In Deliblatska Pescara Protected Area there is an increase of highly mobile lead, most probably originating from the bombing of Pancevo oil industry facilities. Radioactivity in examined sediment samples is in the range of values commonly reported from neighbouring countries, suggesting that the contribution of the Chernobyl accident and NATO bombing in 1999 to the total radioactivity in the examined areas is negligible from the health point of view (i.e. that DU ammunition was not used in these areas).


Ecotoxicology and Environmental Safety | 2018

Integrated approach to environmental pollution investigation – Spatial and temporal patterns of potentially toxic elements and magnetic particles in vineyard through the entire grapevine season

Tijana Milićević; Dubravka Relić; Mira Aničić Urošević; Gordana Vuković; Sandra Škrivanj; Roeland Samson; Aleksandar Popović

An integrated approach to the investigation of potentially toxic elements (PTEs) was applied to the soil and grapevine leaf samples collected from vineyard environment through the grapevine season. To investigate mobile and bioavailable concentrations of PTEs, six single extraction procedures and pseudo-total digestion were applied to the samples. The element concentrations in the samples were measured using inductively coupled plasma-optical emission spectrometry (ICP-OES) and inductively coupled plasma-mass spectrometry (ICP-MS). To assess atmospheric particle deposition, saturation isothermal remanent magnetisation (SIRM) was applied to the leaf samples. The obtained PTE concentrations in samples were used for calculating various ecological implications in the vineyard environment. The notable environmental pollution implications were estimated for As, B, Cd, Co, Cr, Cu, Mn, Ni and Sr. The environmental risk (RI) of the elements soluble under low-acid conditions influenced soil bioavailability risk. The most bioavailable elements from soil to leaves were Mn, Ni and Sr, followed by Cr and Cu. Cadmium and Co were strongly-bonded in the soil and were not bioavailable. The most suitable extractants for assessing bioavailability in the soil-leaf system were chelating agent Na2EDTA, and weak salt solutions CaCl2 and NH4NO3. The biological accumulation concentrations (BACs) of B, Ba, Cd, Co, Ni and Zn were decreasing in the leaves through the grapevine growing phases, that is contributed to the decreasing agrochemical application through the season. The BACs of Co, Cr, Sb and Pb, in July (veraison), were higher than in other phases, which indicate anthropogenic activities. According to correlations between biogeochemical index (BGI) and BAC, Cu and Na were mostly bioaccumulated from soil to leaves due to agrochemical applications, while bioaccumulation of B, Cd, Sb and Sr could be influenced by the other anthropogenic sources. Significant correlations between PTE concentrations and SIRM imply that leaves indicate Co, Cr and Ni air pollution in the vineyard environment.


Chemosphere | 2018

Ranking and similarity of conventional, microwave and ultrasound element sequential extraction methods

Dubravka Relić; Károly Héberger; Sanja Sakan; Biljana Škrbić; Aleksandar Popović; Dragana Đorđević

This study aims to compare three extraction techniques of four sequential element extraction steps from soil and sediment samples that were taken from the location of the Pančevo petrochemical industry (Serbia). Elements were extracted using three different techniques: conventional, microwave and ultrasound extraction. A novel procedure - sum of the ranking differences (SRD) - was able to rank the techniques and elements, to see whether this method is a suitable tool to reveal the similarities and dissimilarities in element extraction techniques, provided that a proper ranking reference is available. The concentrations of the following elements Al, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Si, Sn, Sr, V and Zn were determined through ICP OES. The different efficiencies and recovery values of element concentrations using each of the three extraction techniques were examined by the CRM BCR-701. By using SRD, we obtained a better separation between the different extraction techniques and steps when we rank their differences among the samples while lower separation was obtained according to analysed elements. Appling this method for ordering the elements could be useful for three purposes: (i) to find possible associations among the elements; (ii) to find possible elements that have outlier concentrations or (iii) detect differences in geochemical origin or behaviour of elements. Cross-validation of the SRD values in combination with cluster and principal component analysis revealed the same groups of extraction steps and techniques.


Arhiv Za Higijenu Rada I Toksikologiju | 2018

Canned sea fish marketed in Serbia: their zinc, copper, and iron levels and contribution to the dietary intake

Aleksandar Popović; Dubravka Relić; Danijela Vranić; Jelena A. Babić-Milijašević; Lato Pezo; Jasna Đinović-Stojanović

Abstract The aim of this study was to determine the levels of Zn, Cu, and Fe in three canned fish species marketed Serbia to see if they meet recommended daily intake requirements or exceed safety limits. We collected a total of 207 samples of canned tuna, sardine, and mackerel, in oil or tomato sauce and analysed them with inductively coupled plasma mass spectrometry (ICP-MS) after acid digestion. The highest levels were obtained for Zn (15.1 mg kg-1) and Cu (1.37 mg kg-1) in sardine in oil and tomato sauce, respectively, and for Fe (18.98 mg kg-1) in mackerel in tomato sauce. Our results keep within the ranges reported by several national food databases and available literature data, with a few exceptions. Our findings also single out canned sardines as the richest source of the three essential elements combined. The estimated daily intake (EDI) of the three essential elements, however, was subpar, and ranged between 0.14 % and 0.72 % of the recommended dietary allowance (RDA) for Zn, Cu, and Fe.

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Sanja Sakan

University of Belgrade

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Andrea Gambaro

Ca' Foscari University of Venice

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