A comprehensive geochemical investigation of potentially harmful elements (PHEs) in household dust from the town of Idrija (Slovenia), once a world-famous Hg mining town that is now seriously ...polluted, was performed for the first time. After aqua regia digestion, the content of mercury (Hg), arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), molybdenum (Mo), nickel (Ni), lead (Pb) and zinc (Zn) was measured. PHE-bearing particles were recognised and observed by scanning electron microscopy and energy-dispersive spectrometry before and after exposure to simulated stomach acid (SSA). Mercury binding forms were identified by Hg thermal desorption technique and gastric bioaccessible Hg was estimated after SSA extraction by ICP-MS. With regard to rural and urban background values for Slovenia, high Hg content (6–120 mg/kg) and slightly elevated As content (1–13 mg/kg) were found. Mercury pollution is a result of past mining and ore processing activities. Arsenic content is potentially associated with As enrichment in local soils. Four Hg binding forms were identified: all samples contained Hg bound to the dust matrix, 14 samples contained cinnabar, two samples contained metallic Hg (Hg
0
), and one sample assumingly contained mercury oxide. After exposure to SSA, Hg-bearing phases showed no signs of dissolution, while other PHE-bearing phases were significantly morphologically and/or chemically altered. Estimated gastric Hg bioaccessibility was low (<0.006–0.09 %), which is in accordance with identified Hg binding forms and high organic carbon content (15.9–31.5 %) in the dust samples.
Black deposits covering speleothems, cave walls and floors in Postojna Cave and Predjama Cave (SW Slovenia), and charcoal found in soil outside the Postojna Cave, were studied in order to establish ...their origin and age. SEM/EDS analysis of these deposits from both caves indicated that they are charred plant remains, very similar to oxidised charcoal in soil. Stable carbon isotope δ13C values of −29.41‰ (Črna Jama, P1), −26.9‰ (Predjama), and −25.1‰ (charcoal in soil) confirm their origin from biomass burning. Radiocarbon dating from Postojna Cave (Črna Jama (P1) 8394±35calyrB.P. and Pisani Rov 8235±25calyrB.P.) suggests that the oldest analysed black deposits formed in the Early Holocene (Mesolithic). The age is consistent with soil charcoal found at 1m depth in the surrounding area. Black deposits from Predjama were dated to 4095±25calyrB.P. (Eneolithic) and were caused by burning fires at the cave entrance, as supported by archaeological remains. Prehistoric (2375±20calyrB.P.) charcoal from the upper part of the soil profile (0.5 to 0.6m) and historic (1240±29calyrB.P. or 745calyrCE) black deposits from Postojna Cave (Črna Jama, P2) are related to forest fires, which are most likely human-induced. We interpret the oldest dated black deposits in Postojna Cave as traces of Early Holocene natural forest fires, since fire activity inside Črna Jama and Pisani Rov is not supported by archaeological remains. Favourable cave entrance morphology and microclimate allowed smoke to enter the cave during the winter period and deposit on speleothems. But an anthropogenic cause of forest fires cannot be excluded, since there are well-documented Mesolithic archaeological cave sites located close to the area. The study shows that black deposits on speleothems in caves are an important palaeoenvironmental record and proxy for Holocene climate.
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•Black deposits on speleothems and charcoal in soils in karst area were studied.•SEM/EDS, 14C dating, C stable isotope analysis, organic matter analyses were applied.•Black deposits and charcoal in soil proved forest fires event dating 8200calyrB.P.•Black deposits on cave speleothems are important proxy for Holocene climate.
Geochemical investigation of topsoil from a mixed industrial and residential area in the southern part of the city of Sisak was carried out in order to determine the concentration, spatial ...distribution, metal-bearing phases and sources of Ba, Cr, Cu, Fe, Mn, Ni, Pb, Ti, V, W and Zn by applying inductively coupled plasma mass spectrometry (ICP-MS) and scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS). The uncontrolled industrial development in a very short period of only 50years, beginning in the 1930s and ending in the 1980s, has left a legacy of serious contamination of topsoil. The concentrations of studied elements in topsoil in the industrial zone were generally elevated and at some locations much higher compared to the rest of the Sisak area.
Morphologies and chemical composition of metal-bearing particles in the heavy mineral fraction of three selected soil samples were studied using SEM/EDS. According to the results of the SEM/EDS analysis, the sources of studied elements could be ascribed predominantly to anthropogenic input from steelworks, recycling of steel scrap, ferroalloys production and to a lesser extent to the pedological processes in the soil and parent material. It is concluded that the SEM/EDS results provide significant information about the sources and apportionment of anthropogenic induced contamination in soil, and assist in the interpretation of conventional analytical results.
•Distribution and sources of PHEs in topsoil from Sisak industrial area are studied.•Geochemical maps of PHE spatial distribution imply anthropogenic emission sources.•PHE-bearing phases predominantly originate from steel production and recycling.•Industrial activities during a 50years period left a legacy of serious contamination of topsoil.
► High contents of Zn, Pb, Cr, Ni, Cu, Co were determined in the Meža River sediments. ► Metal-bearing phases were identified in sediments and assigned to three source areas. ► Main sources of metals ...in the Meža River sediments are mine waste deposits, iron-steel industry, bedrock weathering. ► Contribution of the Meža River to the total metal-load in the Drava River is evident.
The Meža River Valley has been a center of mining, ore processing and iron- and steel-based metallurgical industry for more than 300 a. This paper deals with stream sediments draining this area. Loads of potentially toxic metals and metal-bearing phases were investigated 10 a after the cessation of Pb and Zn mining. Sediments in the upper Meža River Valley show significant pollution with Pb and Zn as a consequence of mining and ore processing. The highest contents of Pb and Zn were found in the Meža tributaries, which directly drain mine waste deposits (maximum values: 19,300
mg/kg Pb and 37,900
mg/kg Zn). These results reflect transport of contaminated material from mine waste sites and indicate that the inactive mine and its mine wastes are sources of metal contamination in the surrounding environment. Contents of Cr, Ni, Cu and Co are increased in the lower Meža River Valley, in the area of Ravne, as a result of the iron and steel industry. The contribution of the Meža River to the metal-load in the Drava River is evident.
Metal-bearing phases, identified in stream sediments by SEM/EDS, are assigned to three areas, according to their source and genesis. The Mežica mining district source area is characterized by ore minerals of geogenic/technogenic origin (cerussite, sphalerite, smithsonite and galena), the Ravne source area is characterized by technogenic trace metal-bearing Fe-alloys, Fe-oxides and spherical trace metal-oxides and the Meža and Drava River catchment areas are represented by geogenic metal-bearing accessory and common rock-forming minerals, such as zircon, ilmenite, rutile, sphene, barite and monazite. SEM/EDS analyses of stream sediments agree well with the results of chemical analyses and they prove to be a very useful tool for identification of metal-bearing phases and their characterization according to source and genesis.
This study examined the provenance of stone tesserae from three Roman mosaics from Celje, Slovenia, using optical microscopy, X‐ray fluorescence spectroscopy, scanning electron microscopy, and X‐ray ...diffraction. Nine microfacies were distinguished. Miliolid limestones identified in the white tesserae, and mudstones/laminated wackestones in the black tesserae, suggest they originated from the Karst region. The sparry limestone in the yellow tesserae probably originates from the Mediterranean. The mudstone/wackestone with planktonic foraminifera in the red tesserae originates from an outcrop in southwestern Slovenia. Green tesserae tuffs are of local origin, whereas the white tuffs could originate from Italian Oligo‐Miocene volcanism rhyolites.
Aerosol vertical profiles are valuable inputs for the evaluation of aerosol transport models, in order to improve the understanding of aerosol pollution ventilation processes which drive the ...dispersion of pollutants in mountainous regions. With the aim of providing high-accuracy vertical distributions of particle mass concentration for the study of aerosol dispersion in small-scale valleys, vertical profiles of aerosol mass concentration for aerosols from different sources (including Saharan dust and local biomass burning events) were investigated over the Vipava valley, Slovenia, a representative hot-spot for complex mixtures of different aerosol types of both anthropogenic and natural origin. The analysis was based on datasets taken between 1–30 April 2016. In-situ measurements of aerosol size, absorption, and mass concentration were combined with lidar remote sensing, where vertical profiles of aerosol concentration were retrieved. Aerosol samples were characterized by SEM-EDX, to obtain aerosol morphology and chemical composition. Two cases with expected dominant presence of different specific aerosol types (mineral dust and biomass-burning aerosols) show significantly different aerosol properties and distributions within the valley. In the mineral dust case, we observed a decrease of the elevated aerosol layer height and subsequent spreading of mineral dust within the valley, while in the biomass-burning case we observed the lifting of aerosols above the planetary boundary layer (PBL). All uncertainties of size and assumed optical properties, combined, amount to the total uncertainty of aerosol mass concentrations below 30% within the valley. We have also identified the most indicative in-situ parameters for identification of aerosol type.
In the caves, the formation of cave minerals is a consequence of a variety of chemical reactions, some of them also due to human activity. There are many caves in Slovenia, but sulphate minerals are ...not very often reported and analysed. In this study, the presence of sulphate minerals is detected by SEM/EDS analysis of speleothems from Črna Jama, a cave near Kočevje (southern Slovenia). The cave is characterised by its dark, almost black colour on cave walls, floor and speleothems. Anthropogenic influence in the cave is still visible, including the remains of a fireplace, some inscriptions on the walls and wooden containers. The analyses of some of the black-coated speleothems reveal the presence of calcium sulphate, confirmed by XRD as gypsum. Gypsum crystals are around 50 μm in size, and they occur in thin crusts. Additionally, some rare authigenic baryte crystals a few micrometres in size are detected. The sulphates δ
34
S value in gypsum found on dark coloured speleothems is + 10.4‰ Vienna Canyon Diablo Troilite (VCDT), while the sulphate δ
34
S of the bedrock is + 8.6‰ VCDT. The more likely source of sulphate ions is thus biomass burning rather than bedrock. Also, bedrock and biomass ash are a very probable source of calcium and barium. The highly probable pyrogenous origin of sulphates draws attention to human impact on cave mineralogy.
Calcite precipitates in Slovenian bottled waters Stanič, Tamara Ferjan; Miler, Miloš; Brenčič, Mihael ...
Environmental science and pollution research international,
06/2017, Letnik:
24, Številka:
16
Journal Article
Recenzirano
Storage of bottled waters in varying ambient conditions affects its characteristics. Different storage conditions cause changes in the initial chemical composition of bottled water which lead to the ...occurrence of precipitates with various morphologies. In order to assess the relationship between water composition, storage conditions and precipitate morphology, a study of four brands of Slovenian bottled water stored in PET bottles was carried out. Chemical analyses of the main ions and measurements of the physical properties of water samples were performed before and after storage of water samples at different ambient conditions. SEM/EDS analysis of precipitates was performed after elapsed storage time. The results show that the presence of Mg
2+
, SO
4
2−
, SiO
2
, Al, Mn and other impurities such as K
+
, Na
+
, Ba and Sr in the water controlled precipitate morphology by inhibiting crystal growth and leading to elongated rhombohedral calcite crystal forms which exhibit furrowed surfaces and calcite rosettes. Different storage conditions, however, affected the number of crystallization nuclei and size of calcite crystals. Hollow calcite spheres composed of cleavage rhombohedrons formed in the water with variable storage conditions by a combination of evaporation and precipitation of water droplets during high temperatures or by the bubble templating method.
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