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Povzetek: 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.
Ključne besede: peatland, ground penetrating radar, electrical resistivity tomography, peat probing, peat thickness
Objavljeno v DiRROS: 07.07.2022; Ogledov: 583; Prenosov: 397
Celotno besedilo (23,80 MB)

Povzetek: 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.
Ključne besede: multi-element composition, scanning electron microscopy, oral bioaccessibility, unified BARGE method, urban geochemistry
Objavljeno v DiRROS: 23.06.2022; Ogledov: 567; Prenosov: 220
Celotno besedilo (1,39 MB)

Povzetek: This work aims at evaluating mercury (Hg) occurrence, spatial distribution and speciation in groundwater of the Isonzo/Soča River upper alluvial plain downstream from the Idrija Hg mine (Western Slovenia). Several wells and piezometers were sampled both in static and dynamic mode. On the basis of hydrochemistry and isotopic composition, the main sources of groundwater were established. Hg concentrations in the Slovenian sector, supplied by local rainfall, are comparable to values measured close to the Isonzo River. Possible further Hg local sources have been suggested. Stability field analysis for the aqueous Hg species revealed that in the presence of chloride Hg solubility may be increased by the formation of chlorocomplexes. Mercury that rarely enters reduced surrounding conditions can be bound to sulphur to form polysulphide species depending on the pH of water. Since Hg-contaminated alluvial sediments of the Isonzo River may act as a secondary Hg source in groundwater, a borehole was dug down to the water table. Mercury content and speciation revealed that cinnabar (HgS) is the prevalent form followed by the matrix-bound Hg (Hgbound). Variations of the physico-chemical boundary conditions, as well as the raising/lowering of the water table, may be locally responsible for the slight variability of Hg concentrations in the aquifer.
Ključne besede: aquifers, groundwater, mercury
Objavljeno v DiRROS: 22.06.2022; Ogledov: 560; Prenosov: 289
Povezava na celotno besedilo

Povzetek: Street Dust (SD) acts as a sink and source of atmospheric particles containing Potentially Toxic Elements (PTEs) and can pose a possible pathway of PTEs to human bodies. Comprehensive SD study, where 249 samples were collected from rural, urban and industrialized areas aimed to increase the understanding between sedimentation of atmospheric dust derived from anthropogenic activities and elemental composition of SD. Elemental composition for 53 elements (ICP-MS, aqua regia digestion) was determined on fraction <0.063 mm. Significantly increased levels of Sn-Cu-Sb-Bi-Ag-Ba-Mo-Pt-Pb and other elements have been detected in urban environments, compared to the rural ones. SEM/EDS investigation identified that main carriers of Ba, Cu and Sn are most likely particles derived from non-exhaust traffic emissions. Areas around steel mills show a strong enrichment with Cr, Mo, Ni and W, which exponentially decreases with the increased distance from the plant, reaching corresponding urban background 15 and 20 km from the source. SEM/EDS inspection identified spherical and melted irregular particles as the main carriers of the above-mentioned elements. City managers shall adapt measures to reduce amount of vehicular traffic and quantity of deposited SD on the public surfaces and encourage green city planning, while industrial emitters are encouraged to reduce their dust emissions.
Ključne besede: ironwork, pollution, potentially toxic elements, Slovenia, traffic
Objavljeno v DiRROS: 10.06.2022; Ogledov: 600; Prenosov: 292
Celotno besedilo (10,32 MB)

Povzetek: Slope stability strongly depends on the prevailing hydrological and hydrogeological conditions. The amount and intensity of precipitation and changing groundwater levels are important landslide triggering factors. Environmental tracers, including the chemical and stable isotope compositions of precipitation and groundwater, were used to gain insight into the groundwater dynamics of the Urbas landslide. The landslide is situated in a mountainous area with steep slopes and high precipitation amount and poses a high risk for the safety of the Koroška Bela settlement that lies downstream. The stable isotope analyses of oxygen-18 (18O) and deuterium (2H) in the precipitation and groundwater were used to estimate the groundwater mean residence time and the average altitude of the landslide recharge area. This information will help to plan and prioritize remedial landslide measures aiming to reduce the recharge of the landslide body and, thus, lower the risk of transformation of the sliding material into debris flow. The results of the chemical analysis of samples taken from springs and a piezometer show a Ca–HCO3 water type. This indicates low water–rock interaction in a landslide area composed of Upper Carboniferous and Permian clastic rocks and points to upper laying carbonate rocks and scree deposits as the main recharge area. Water samples for stable isotope analyses of δ18O and δ2H were collected from a rain gauge, springs, and a piezometer over a two-year period (2018–2020). The estimated mean recharge altitude of the groundwater at sampling points was from approximately 1700 to 1800 m a.s.l. with a mean residence time of 2–5 months.
Ključne besede: landslide, groundwater, stable isotopes, oxygen-18, deuterium, hydrogeology, recharge dynamic
Objavljeno v DiRROS: 16.03.2022; Ogledov: 745; Prenosov: 308
Celotno besedilo (3,55 MB)