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Query: "author" (Robert Šajn) .

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1.
Investigations of chemical element distributions in soil, North Macedonia—a review
Trajče Stafilov, Robert Šajn, Jasminka Alijagić, 2024, original scientific article

Abstract: This review article considers the following aspects: naturally distributed chemical elements and their enrichments, and the increased occurrence of PTEs due to anthropogenic and urban activities, as well as due to the geochemical uniqueness of certain geochemical landscapes, depending on the lithological environment. The review article is the result of many years of successful cooperation between the Geological Survey of Slovenia and the Faculty of Natural Sciences in Skopje, Ss. Cyril and Methodius University in Skopje, as well as several other institutions from North Macedonia, Russia and Romania but, also, through the voluntary and enthusiastic work of Prof. Trajče Stafilov’s PhD and Master’s students. To create the Geochemical Atlas, the territory of North Macedonia was covered with 995 sampling locations, but 16 separate areas with soil contamination were additionally sampled. The total sum of all collected soil samples was 3983 from 2449 different sampling sites in the period from 2006 to 2017. The analyses were performed at the Institute of Chemistry, Faculty of Natural Sciences in Skopje, at the Ss. Cyril and Methodius University in Skopje, North Macedonia, at the Research Institute for Analytical Instrumentation (ICIA), Cluj-Napoca, Romania, at the Joint Institute for Nuclear Research in Dubna, Moscow Region, Russia, and at Acme Labs in Vancouver, Canada. The sum of all analysed soil samples in all four mentioned laboratories was 7991 from 2006 to 2017. Using advanced mathematical methods such as multivariate statistical methods (HCA, FA, PCA) and artificial neural networks–multilayer perceptron (ANN-MP), predictions were made about the concentrations of potentially toxic elements (PTEs) and their distribution in real space. In less than two decades (2007–2023) of fruitful collaboration, a large number of scientific works have been published: 188 scientific publications, 8 geochemical atlases and 23 chapters in monographs.
Keywords: chemical elements, distribution, pollution, soil, North Macedonia
Published in DiRROS: 25.03.2024; Views: 124; Downloads: 85
.pdf Full text (86,55 MB)

2.
Moss as a biomonitor to identify atmospheric deposition of minor and trace elements in Macedonia
Robert Šajn, Katerina Bačeva Andronovska, Trajče Stafilov, Lambe Barandovski, 2024, original scientific article

Abstract: The present work was carried out to obtain and highlight the fifth comprehensive baseline dataset on atmospheric deposition of trace elements and to assess air quality in Macedonia. In the period from August to September 2020, a total of 72 moss samples were collected in accessible areas in the country. The content of 28 elements (Ag, Al, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, Ga, Hg, K, La, Mg, Mn, Mo, Na, Ni, P, Pb, S, Sb, Sc, Sr, Ti, U, and Zn) was determined using inductively coupled plasma–mass spectrometry. Based on the data obtained on the content of the elements, a factor analysis was carried out to identify and characterise different sources of pollution. In addition, distribution maps were created for all elements to show the regions most affected by anthropogenic activities. The survey conducted in 2020 has shown that air pollution with potentially toxic elements (PTEs) has slightly decreased compared to the results of the previous survey from 2015. This is due to the fact that, despite the operation of all mining and smelting facilities with the same capacity, government regulations for the installation of cleaning systems and additional regulations to reduce pollution have been introduced in the last five years. Nevertheless, the fact remains that the highest anthropogenic air pollution with PTEs is still caused by the operation of the ferronickel smelter in Kavadarci (Ni and Cr) in the southern part and by the lead and zinc mines in Probištip, Makedonska Kamenica, and Kriva Palanka in the eastern part of the country (Cd, Pb, and Zn).
Keywords: moss, atmospheric deposition, trace elements, air quality, Macedonia
Published in DiRROS: 20.03.2024; Views: 109; Downloads: 39
.pdf Full text (9,64 MB)

3.
Assessment of atmospheric deposition of potentially toxic elements in Macedonia using a moss biomonitoring technique
Lambe Barandovski, Trajče Stafilov, Robert Šajn, Katerina Bačeva Andronovska, Marina V. Frontasyeva, Inga Zinicovscaia, 2024, original scientific article

Abstract: This study aims to investigate the changes in atmospheric deposition trends in Macedonia, using a moss biomonitoring technique. This technique has been used to assess the content of potentially toxic elements in Macedonia in 2002, 2005, 2010, and 2015, within the framework of the International Cooperative Program on Effects of Air Pollution on Natural Vegetation and Crops. The content of 42 elements was analyzed using instrumental neutron activation analysis (INAA), inductively coupled plasma–atomic emission spectrometry (ICP–AES), and atomic absorption spectrometry (AAS), on 72 moss samples collected in the summer of 2015. The median values of the elements studied were compared with data from previous years and with median values obtained from comparable studies in Norway and the neighboring countries. Through factor and cluster analysis, three geogenic factors were identified: Factor 1, which includes the elements Al, Ce, Fe, Hf, La, Li, Na, Sc, Sm, Tb, Ti, Th, V, and U; Factor 4, which includes As, Cl, and I; and Factor 5, which includes the elements Ba and Sr. In addition, one geogenic-anthropogenic factor containing Co, Cr, and Ni (Factor 2), was identified, and one anthropogenic factor containing Cd, Pb, Sb, and Zn (Factor 3). The lead and zinc mines near the towns of Kriva Palanka, Probištip, and Makedonska Kamenica in the eastern region of the country, the former lead and zinc smelter in the town of Veles, and the ferronickel smelter near Kavadarci, have continuously had the greatest anthropogenic impact on the atmospheric deposition of potentially toxic elements during the time period of the study. In addition to the human influences, the lithology and the composition of the soil continue to play a significant role in the distribution of the elements.
Keywords: moss, biomonitoring, air pollution, potentially toxic elements, Macedonia
Published in DiRROS: 06.02.2024; Views: 162; Downloads: 53
.pdf Full text (9,82 MB)

4.
Secondary deposits as a potential REEs source in South-Eastern Europe
Robert Šajn, Jasminka Alijagić, Ivica Ristović, 2024, original scientific article

Abstract: The main objective of this manuscript is to collect, classify, and compile all available data about secondary mineral sources of REEs in the South-Eastern Europe (SEE). The material is generated from the extracting and processing sector, that might be possibly transformed in the business process becoming an important raw material for another industry. The management inventory guide will strengthen communication and dissemination efforts and simultaneously contribute to Europe’s self-sufficiency and support transitioning to green and digital technology. Identification of the knowledge gaps associated with secondary sources of REEs in SEE will contribute to connections between all partners being involved at the beginning, during the lifetime of products and at the end of the life cycle, represented with deposit owners, technology developers and potential processors, producers, and potential users. At the investigated area it was found 1835 individual landfills, most of them belonging to waste rocks. The total quantity of all material in SRM is about 3.2 billion tons on an area of about 100 km2. The largest 95 individual landfills were selected as potential prospective landfills, containing about 1600 million tons of material. The estimated total potential of REEs (ΣREE) is more than 200 Kt. The largest quantities are found in landfills for coal fly ash and Cu flotation, which correspond to more than 80% of the ΣREE. Most of the promising sites are located in Serbia and North Macedonia. It has been calculated that the valorisation potential and perspectivity of REE2O3 is about 32.5 billion USD (prices from December 2022). According to the average concentrations of REEs, the most prospective are the red mud dams but their total volume is limited compared to massive amounts of coal fly ash landfills. The REEs content in all type of investigated materials, especially in coal fly ash in North Macedonia is twice as high as in other countries.
Keywords: secondary raw materials, ESEE, rare elements, economic prospective
Published in DiRROS: 06.02.2024; Views: 151; Downloads: 40
.pdf Full text (12,40 MB)

5.
Multivariate statistical methods in determining the spatial distribution of chemical elements in soil from the Mavrovo-Rostuše region, North Macedonia
Trajče Stafilov, Robert Šajn, Kristina Petrovska, 2023, original scientific article

Abstract: In this work, the contents and spatial distributions of 19 elements (Ag, Al, B, Ba, Ca, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, P, Pb, Sr, V, Zn) in the soil of the western part of North Macedonia (Mavrovo-Rostuše region) are presented. For this purpose, a total of 66 soil samples were collected from 33 locations (33 samples of topsoil, 0-5 cm, and 33 samples of subsoil, 20-30 cm). All samples were analysed by inductively coupled plasma - atomic emission spectrometry (ICP-AES) after complete digestion with four acids (HNO3, HF, HClO4 and HCl). The obtained results were statistically evaluated and spatial distribution maps for all analysed elements were also prepared. Factor analysis was performed to reduce the number of data used and new synthetic variables (factors) were identified. Through the application of factor analysis, three geochemical associations were identified: Factor 1 (Zn, K, Cu, Fe, and Li), Factor 2 (Cr, Ni, and Mg) and Factor 3 (Ca and Al). From the obtained data and the maps of spatial distribution, it could be concluded that the distribution of the analysed elements is related to the lithology of the region. Thus, it was found that the higher content of elements of Factor 1 occurs in the eastern and southern part of the study area (middle and lower reaches of the Radika River and along the Mala River), where Mesozoic and Paleozoic carbonates as well as Paleozoic shales and Paleogene flysch prevail. Factor 2 (Cr, Ni and Mg) also represents a lithogenic association. The highest contents of the elements in both soil layers were found in the areas where Paleozoic sandstones and shales (village of Lazaropole and the area around the Mavrovo Lake) and Paleogene flysch (Rostuše village) predominate. Factor 3 (Ca and Al) also represents lithogenic association of elements. The highest content of these elements was found in the northwestern part of the study area (village of Žirovnica and along the Berička River) and in the northeastern region above the village of Brodec where Mesozoic carbonates and Paleogene flysch dominate.
Keywords: soil, heavy metals, spatial distribution, Mavrovo-Rostuše region, North Macedonia
Published in DiRROS: 04.01.2024; Views: 190; Downloads: 48
.pdf Full text (1,90 MB)

6.
Application of multivariate statistical methods for determining geochemical trends of elements on the territory of Slovenia
Robert Šajn, Mateja Gosar, Jasminka Alijagić, Tamara Teršič, 2024, original scientific article

Abstract: The main objective of this study is to map multi-element geochemical anomalies in soil on a regional scale. We aimed to determine and evaluate the baseline geochemical values and main geochemical trends in soil that may serve as reference values against any future changes. A total of 817 topsoil samples (0–10 cm) were collected in a 5 × 5 km grid and analyzed for 35 elements using ICP-ES after multi-acid digestions (HClO4/HNO3/HCl/HF) and 53 elements using ICP-MS after modified aqua regia digestion (HCl/HNO3/H2O). The analytical results for the two different digestion methods (multi-acid digestion vs. aqua regia) were also compared for each chemical element. Multivariate statistical methods were applied to identify the geochemical trends and main sources of trace elements over the territory of Slovenia. Based on these results, seven natural and one mixed natural/anthropogenic geochemical association were established. The contents and trends of the determined factors are presented according to 8 natural units, 4 drainage areas, and geological units characteristic of Slovenia. The identified anthropogenic geochemical association combines toxic elements (Ag, Bi, Cd, Hg, P, Pb, S, Sn, and Zn). Increased values of these elements can be found in mining areas and metallurgic centers, in Quaternary sediments of the Sava River, and Adriatic Basin as the consequence of past mining activities and in the Julian Alps, where their origin could be connected to the atmospheric deposition.
Keywords: soil, geochemical mapping, distribution of geochemical elements, factor analysis, cluster analysis
Published in DiRROS: 04.01.2024; Views: 192; Downloads: 47
.pdf Full text (9,92 MB)

7.
Distribution of chemical elements in surface waters from the Strumica River Basin, North Macedonia
Katerina Trajanova, Robert Šajn, Trajče Stafilov, 2023, original scientific article

Abstract: In this work, the distribution of chemical elements in samples of surface water from the Strumica River Basin, North Macedonia, was studied. The water samples were collected from a total of twelve sites. In addition to the Strumica River, samples were collected from its tributaries: Bansko, Dabile, Turija, Vodoča, Radoviška, and Injevska. The determination of the concentration of 21 elements (Ag, Al, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, Sr, V, and Zn) was performed by inductively coupled plasma - atomic emission spectrometry (ICP-AES). All detailed information on the studied items was statistically processed using Stat Soft, 11.0 software. Using the obtained data on the concentration of the studied elements, descriptive statistical analysis of the values ​​for the concentration of the elements was performed. A map of spatial distribution was obtained for each element. The obtained results show that the concentrations of the studied elements in the surface water samples are relatively low and the distribution of most of the elements follows the lithology of the study area.
Keywords: rivers, surface water, heavy metals, Strumica River Basin, North Macedonia
Published in DiRROS: 20.07.2023; Views: 331; Downloads: 105
.pdf Full text (2,11 MB)

8.
Preliminary chemical and mineralogical characterization of tailings from base metal sulfide deposits in Serbia and North Macedonia
Timotheus Martin Christoph Steiner, Viktor Bertrandsson Erlandsson, Robert Šajn, Frank Melcher, 2022, original scientific article

Abstract: Tailings of old mines often contain metals, which were not of economic interest or could not be recovered with the existing technology at the time of active mining. This is especially true for metals that often occur as by-products in Cu-Pb-Zn-(Ag-Au) ores as Sb, Mo, Ge, and In. A fundamental characterization of some tailings is presented in terms of their mineralogy and content of valuable metals which could be extracted to finance a possible remediation and improve the supply of the EU with critical metals. Tailings from active and abandoned mines in Serbia (Bor, porphyry Cu/Au; Krivelj, porphyry Cu/Au; Blagodat, hydrothermal Pb-Zn; Lece, epithermal Au; Rudnik, hydrothermal/skarn Pb-Zn) and North Macedonia (Sasa, Pb-Zn; Probištip, Pb-Zn; Bučim, porphyry Cu; Lojane, fault-bound vein-type low-temperature As, Sb, Cr at the contact of rhyolite and serpentinite) were studied. Analysis for major and trace elements used a multi-method approach (lithium borate fusion and ICP-MS/OES analysis, gravimetric analysis, instrumental neutron activation analysis, total digestion ICP-OES, infrared spectroscopy) with mineral identification by scanning electron microscopy. Concentrations of the major commodity elements (Cu, Pb, Zn, Au, Ag) varies within several orders of magnitude depending on mineralogy and ore type. Critical metals (Co, Ga, Ge, Sb) contents are low with some exceptions. Some tailings contain moderate to elevated potentially toxic element levels (As, Cd, Pb, Tl). For the sample from Probištip which yielded the highest valuable metal concentrations (>5000 ppm Pb, 4020 ppm Zn), a heavy mineral concentrate of the sand size fraction (0.06 mm to 0.5 mm) was produced and analyzed by SEM and LA-ICP-MS for additional rare phases and trace elements. In all tailings studied, additional milling would be needed to separate ore from gangue minerals. Increasing metal prices might facilitate feasibility studies for some of the localities in the future, despite the limited quantitative information about the characterized tailings.
Keywords: rudniški odpadki, kemija, mineralogija, rudna nahajališča, sulfidi
Published in DiRROS: 22.11.2022; Views: 547; Downloads: 162
.pdf Full text (4,76 MB)

9.
The primary and secondary mineral resources of Montenegro and their mapping into the European data model
Slobodan Radusinović, Robert Šajn, Božica Jovanović, Duška Rokavec, Katarina Hribernik, Vasilije Abramović, Matej Draksler, Ivan Danilović, Mia Jovanović, 2022, original scientific article

Abstract: Primary and secondary mineral resources are of strategic importance to the EU economy. Montenegro, as a country candidate for membership in the EU, is required to follow (and later to implement) European policies, strategies as well as initiatives, including those related to mineral resources and the mining sector. The importance of providing access to mineral raw materials in the future is recognized by the EU, as well as meeting the needs of European industry, maintaining employment and ensuring further development. Considering the overall economic situation in Montenegro, it is important to encourge the mining sector and other industries based on the use of mineral resources in making a greater contribution to the development and sustainability of society as a whole and also increase the share of national GDP. The potential for discovery and utilization of primary and secondary mineral resources in Montenegro is demonstrated. The most important metallic mineral resources are bauxite, lead and zinc, while conventional energy resources include coal (oil and gas potential has yet to be proven). In addition, there are abundant non-metallic mineral raw materials - industrial minerals and construction materials. Secondary mineral resources, especially aluminous red mud (bauxite residue), are also significant and have been the subject of research in recent years. Tailings from flotation processes at operating and abandoned lead and zinc mines might also be of interest for metal recovery. Bottom and flay ash from thermal power plants, slag from steel production, as well as marlstone and limestone from the hanging wall of coal deposits may also have potential. Waste rocks could be used particularly for secondary aggregate production. A database was developed and the most important deposits of primary and secondary mineral resources in Montenegro were mapped during the RESEERVE project. Mineral data were harmonised so as to be INSPIRE compliant. In addition, some novel geochemical exploration results of secondary mineral resources are presented.
Keywords: primary and secondary mineral resources, Montenegro, RESEERVE project, European geological data platform (EGDI), INSPIRE
Published in DiRROS: 16.11.2022; Views: 426; Downloads: 169
.pdf Full text (8,52 MB)

10.
Biomonitoring and assessment of toxic element contamination in floodplain sediments and soils using fluorescein diacetate (FDA) enzymatic activity measurements: evaluation of possibilities and limitations through the case study of the Drava River floodplain
Péter Szabó, Gyozo Jordan, Tamás Kocsis, Katalin Posta, Levente Kardos, Robert Šajn, Jasminka Alijagić, 2022, original scientific article

Abstract: The EU Water Framework Directive requires the monitoring and evaluation of surface water sediment quality based on the assessment of risk posed by contamination on the biotic receptors. Floodplain sediments are important receptors of potentially toxic element (PTE) contamination from the upstream catchment areas, and floodplains host climate-sensitive riverine ecosystems and fertile agricultural areas at the same time. This study investigates the effect of PTE contamination on microbial communities in floodplain sediments and soils using the fast, inexpensive and reliable fluorescein diacetate (FDA) method in order to estimate its applicability for sediment quality monitoring and preliminary toxicity-based risk assessment. Sediment and soil samples were collected from the actively flooded alluvial plain and the river terrace areas along a 130-km stretch of the large Drava River floodplain known to be widely contaminated by historical mining, smelting and the associated industry in the upstream Alpine region. Results of detailed data analysis show that the total microbial activity represented by the measured FDA values is related to PTE (As, Cu, Zn, Cd, Pb) concentrations, but this relationship shows significant heterogeneity and depends on the spatial location and on the soil properties such as organic matter content, dissolved salt and nutrient content, and it is specific to the toxic elements. Results show that some microbe species appear to be able to adapt to the elevated PTE concentrations in toxic soil micro-environments, over time. Despite the observed heterogeneity of microbial activity, the results revealed a breakpoint in the FDA dataset around the FDA = 3 FC (fluorescein concentration) value suggesting that microbial activity is controlled by thresholds.
Keywords: potentially toxic elements, fluorescein diacetate activity, heavy metals, contamination, biological activity
Published in DiRROS: 25.08.2022; Views: 643; Downloads: 199
.pdf Full text (6,23 MB)

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