1. Application of multivariate statistical methods for determining geochemical trends of elements on the territory of SloveniaRobert 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: 204; Downloads: 51
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3. Doktrinarni problemi diagnostičnega algoritma retroperitonealnega prostoraJurij Us, Franci-Stanko Marolt, Marjeta Stanovnik, Jože Stropnik, Erika Brenčič, Marjeta Demšar, V. Istenič, E. Baretič-Kolar, Marko Kralj, 1982, professional article Keywords: radiologija, intervencijska radiologija
Published in DiRROS: 14.09.2023; Views: 256; Downloads: 61
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5. Evasion of gaseous elemental mercury from forest and urban soils contaminated by historical and modern ore roasting processes (Idrija, Slovenia)Federico Floreani, Elena Pavoni, Mateja Gosar, Stefano Covelli, 2023, original scientific article Abstract: Considerable amounts of gaseous elemental mercury (Hg0) can be released into the atmosphere from Hg-enriched substrates, such as those from former mining areas, posing a potential environmental threat. In this work, Hg0 fluxes at the soil–air interface under natural vegetation covers were measured in various locations within the Idrija Hg mining area (Slovenia) and its surroundings. Sites were selected in order to compare Hg0 fluxes from both forest soils heavily impacted by historical ore roasting and urban soils characterised by a different degree of Hg enrichment due to the natural occurrence of Hg in rocks or recent mining and roasting processes. Replicate measurements at each site were conducted using a non-steady state flux chamber coupled with a real-time Hg0 analyser (Lumex RA-915M). Moreover, topsoil samples (0–2 cm) were analysed for Hg total concentration and speciation. Cinnabar was the predominant Hg form in almost all the sites. Despite Hg0 being undetectable in soils using thermo-desorption, substantial emissions were observed (70.7–701.8 ng m−2 h−1). Urban soils in a naturally enriched area showed on average the highest Hg0 fluxes, whereas relatively low emissions were found at the historical roasting site, which is currently forested, despite the significantly high total Hg content in soils (up to 219.0 and 10,400 mg kg−1, respectively). Overall, our findings confirm that shading by trees or litter may effectively limit the amount of Hg0 released into the atmosphere even from extremely enriched soils, thus acting as a natural mitigation.
Keywords: legacy soil contamination, Hg mining, gaseous Hg fluxes, flux chamber, ore roasting, Hg speciation
Published in DiRROS: 30.06.2023; Views: 404; Downloads: 113
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6. Solid carriers of potentially toxic elements and their fate in stream sediments in the area affected by iron ore mining and processingSaša Kos, Nina Zupančič, Mateja Gosar, Miloš Miler, 2022, original scientific article Abstract: The potential environmental impact of historical mining and ore processing on stream sediments and water was studied in a small siderite iron ore deposit with diverse sulfide mineral paragenesis. The main aim was to characterize solid carriers of potentially toxic elements (PTEs) in stream sediments and mine waste, to understand their fate in fluvial systems. General mineralogy (X-ray powder diffraction) and individual solid PTE carriers (scanning electron microscopy/energy dispersive spectroscopy) were correlated with the geochemical composition of stream sediments, mine waste, and stream waters (inductively coupled plasma mass spectrometry). Primary solid PTE carriers were pyrite, chalcopyrite, sphalerite, Hg-bearing sphalerite, galena, and siderite. Slightly alkaline and oxidizing conditions in stream water promoted the transformation of primary phases into secondary PTE carriers. Fe(Mn)-oxide/oxyhydroxides were major sinks for Pb, Zn, and As. Compared to background levels, Co (14.6 ± 2.1 mg/kg), Cu (30 ± 2.9 mg/kg), Ni (32.1 ± 2.9 mg/kg), Pb (64.5 ± 16.4 mg/kg), Zn (175.3 ± 22.5 mg/kg), As (81.1 ± 63.7 mg/kg), and Hg (2 ± 0.8 mg/kg) were elevated in mining area. Mine waste contained similar PTE carriers as stream sediments, but much higher PTE contents. Prevailingly low PTE concentrations in streams, with the exception of As (1.97 ± 2.4 µg/L) and Zn (4.5 ± 5.7 µg/L), indicate the stability of PTE carriers. Environmental effects were not significant, and additional monitoring is recommended.
Keywords: environmental mineralogy, environmental geochemistry, potentially toxic elements, stream sediments, solid phases, iron ore deposit, SEM/EDS
Published in DiRROS: 16.11.2022; Views: 538; Downloads: 175
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7. Characterization of atmospheric deposition as the only mineral matter input to ombrotrophic bogValentina Pezdir, Martin Gaberšek, Mateja Gosar, 2022, original scientific article Abstract: Ombrotrophic peatlands contain a very small percentage of mineral matter that they receive exclusively from atmospheric deposition. Mineral matter deposited on the Šijec bog was characterized using scanning electron microscopy coupled with energy dispersive spectroscopy (SEM/EDS). We collected solid atmospheric deposition from snow, rainwater, and using passive samplers. Samples were collected at average atmospheric conditions and after two dust events. Size, morphology, and chemical composition of individual particles were determined. We distinguished four main particle groups: silicates, carbonates, organic particles, and Fe-oxyhydroxides. Silicate particles are further divided into quartz and aluminosilicates. Proportions of these groups vary between samples and between sample types. In all samples, silicate particles predominate. Samples affected by dust events are richer in solid particles. This is well observed in passive deposition samples. Carbonates and organic particles represent smaller fractions and are probably of local origin. Iron-oxyhydroxides make up a smaller, but significant part of particles and are, according to their shape and chemical composition, of both geogenic and anthropogenic origin. Estimated quantity and percentage of main groups vary throughout the year and are highly dependent on weather conditions. Dust events represent periods of increased deposition and contribute significantly to mineral matter input to peatlands.
Keywords: atmospheric deposition, SEM/EDS, mineral matter, peatland
Published in DiRROS: 08.09.2022; Views: 547; Downloads: 258
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8. Investigating peatland stratigraphy and development of the Šijec bog (Slovenia) using near-surface geophysical methodsValentina Pezdir, Teja Čeru, Barbara Horn, Mateja Gosar, 2021, original scientific article Abstract: Owing to their anoxic environment, peatlands play an important role in the preservation of records documenting past atmospheric depositions. To determine past records, data on peat stratigraphy and bog development are needed. Ground penetrating radar (GPR) was used to determine the peat thickness and morphology of the Šijec bog on the Pokljuka plateau in Slovenia, which will serve as a basis for further geochemical studies. Information on the stratigraphy below the peat/clay boundary was acquired by applying electrical resistivity tomography (ERT). The GPR results reveal four depressions within the peat bog, which are separated by elevated ridges. Within the depressions the peat reaches a depth of 6–9 m. The edges of the bog are flat, with peat thickness ranging from 2 to 4 m. The reach of the GPR was complemented with manual peat probing. A comparison of the depths obtained using GPR and the peat probe reveals that the results of both methods correspond well in most locations. The ERT indicated similar peat depths; peat responds with high electrical resistivity. In contrast, clayey sediments with low resistivity are found below the peat. The peat depressions are underlain with larger clayey depressions reaching more than 20 m in thickness and represent lake sediments. The complementary geophysical methods proved to be an efficient approach with which we can delineate the peat morphology and the underlying stratigraphy. Both indicate bog formation from a lake with four deeper depressions, that are separated by glacial deposits. The results presented here show the potential for geophysical methods to infer formational processes in peatlands, showing the presence of a series of isolated basins that later coalesced into a single peat landform. This interpretation is consistent with previous conceptual models from studies in boreal regions.
Keywords: peatland, ground penetrating radar, electrical resistivity tomography, peat probing, peat thickness
Published in DiRROS: 07.07.2022; Views: 583; Downloads: 397
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9. Attic dust: an archive of historical air contamination of the urban environment and potential hazard to health?Martin Gaberšek, Michael J. Watts, Mateja Gosar, 2022, original scientific article Abstract: A comprehensive study of attic dust in an urban area is presented. Its entire life cycle, from determining historical emission sources to recognising the processes that take place in attic dust and its potential to impact human health is discussed. Its chemical composition and morphological characteristics of individual solid particles reflect past anthropogenic activities. High levels of Be-Cd-Cu-Sb-Sn-Pb-Te-Zn and occurrence of Cu-Zn shavings are typical for an industrial zone characterised by a foundry and a battery factory. High levels of Co-Fe-Mo-Ni-W-Ba-Cr-Mg-Mn-Nb-Ti and occurrence of various solid Fe-oxides, particularly spherical particles, were identified in another industrial zone, which was dominated by the automotive and metal-processing industries. Emissions from coal combustion affected the distribution of S-Se-Hg-Tl-As-Ag-U. The predominant mineral in attic dust is gypsum, which was presumably formed in situ by the reaction of carbonate dust particles and atmospheric SO2 gas. The high oral bioaccessibility of As-Cd-Cu-Pb-Zn in the gastric phase and high bioaccessibility of As-Cu-Cd-Ni in the gastrointestinal phase were identified. Determined characteristics of attic dust and identified possibilities of prolonged human exposure to it indicate that attic dust should be treated as an excellent proxy for historical air contamination as well as a potentially hazardous material for human health.
Keywords: multi-element composition, scanning electron microscopy, oral bioaccessibility, unified BARGE method, urban geochemistry
Published in DiRROS: 23.06.2022; Views: 567; Downloads: 220
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10. Assessment of natural zeolite clinoptilolite for remediation of mercury-contaminated environmentIvona Nuić, Mateja Gosar, Marin Ugrina, Marina Trgo, 2022, original scientific article Abstract: The soil at ancient roasting sites in the surroundings of the Idrija mine (Slovenia) is highly contaminated with mercury. To assess the impact of mercury on groundwater by infiltration and find an eco-friendly remediation method, the leaching of mercury from the soil containing 1347 mg Hg/kg, followed by sorption of the total leached mercury on cost-effective natural zeolite (NZ) clinoptilolite, was performed. The leaching of soil in ultrapure water of pHo = 3.00–11.46 after 24 h resulted in the total leached mercury concentration in the range 0.33–17.43 µg/L. Much higher concentrations (136.9–488.0 µg/L) were determined after the first few hours of leaching and were high above the maximum permissible level in water for human consumption. The NZ showed very good sorption of the total leached mercury, with a maximum removal efficiency of 94.2%. The leaching of mercury in presence of the NZ resulted in a significant decrease of the total leached mercury (1.9–20.3 µg/L compared to 12.8–42.2 µg/L), with removal efficiencies up to 90.5%, indicating immobilization of mercury species. The NZ has a great potential for economically viable remediation of mercury-contaminated environment. However, efforts should be made in the further study of mercury leachability to reduce the mercury concentration in water to acceptable levels.
Keywords: Idrija mine, mercury-contaminated soil and water, leaching, natural zeolite clinoptilolite, remediation
Published in DiRROS: 23.06.2022; Views: 590; Downloads: 465
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