Digitalni repozitorij raziskovalnih organizacij Slovenije

Iskanje po repozitoriju
A+ | A- | Pomoč | SLO | ENG

Iskalni niz: išči po
išči po
išči po
išči po


Iskalni niz: "avtor" (Mateja Gosar) .

1 - 8 / 8
Na začetekNa prejšnjo stran1Na naslednjo stranNa konec
Characterization of atmospheric deposition as the only mineral matter input to ombrotrophic bog
Valentina Pezdir, Martin Gaberšek, Mateja Gosar, 2022, izvirni znanstveni članek

Povzetek: 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.
Ključne besede: atmospheric deposition, SEM/EDS, mineral matter, peatland
Objavljeno v DiRROS: 08.09.2022; Ogledov: 100; Prenosov: 52
.pdf Celotno besedilo (3,51 MB)
Gradivo ima več datotek! Več...

Investigating peatland stratigraphy and development of the Šijec bog (Slovenia) using near-surface geophysical methods
Valentina Pezdir, Teja Čeru, Barbara Horn, Mateja Gosar, 2021, izvirni znanstveni članek

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: 161; Prenosov: 70
.pdf Celotno besedilo (23,80 MB)

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, izvirni znanstveni članek

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: 151; Prenosov: 77
.pdf Celotno besedilo (1,39 MB)

Assessment of natural zeolite clinoptilolite for remediation of mercury-contaminated environment
Ivona Nuić, Mateja Gosar, Marin Ugrina, Marina Trgo, 2022, izvirni znanstveni članek

Povzetek: 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.
Ključne besede: Idrija mine, mercury-contaminated soil and water, leaching, natural zeolite clinoptilolite, remediation
Objavljeno v DiRROS: 23.06.2022; Ogledov: 170; Prenosov: 69
.pdf Celotno besedilo (54,30 MB)

Retrieval of vertical mass concentration distributions
Longlong Wang, Samo Stanič, Klemen Bergant, William Eichinger, Griša Močnik, Luka Drinovec, Janja Vaupotič, Miloš Miler, Mateja Gosar, Asta Gregorič, 2019, izvirni znanstveni članek

Povzetek: 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.
Ključne besede: valley air pollution, aerosol vertical distributions, lidar remote sensing, in-situ measurements, aerosol identification
Objavljeno v DiRROS: 03.03.2022; Ogledov: 238; Prenosov: 93
URL Povezava na celotno besedilo

Celostna obravnava geokemije trdnih anorganskih delcev v urbanem okolju
Martin Gaberšek, 2020, doktorska disertacija

Povzetek: Biogeokemično kroženje elementov je v urbanih okoljih zaradi velikega števila prebivalcev in njihovih različnih dejavnosti precej drugačno kot v naravnih. Zaradi kompleksnosti urbanih okolij, je pri geokemičnih raziskavah treba uporabiti celosten pristop. To pomeni, da s kombinacijo različnih metod preučujemo vsebnosti in pojavljanje potencialno strupenih elementov (PSE) v več urbanih materialih. V okviru doktorske disertacije smo na urbanem območju Maribora raziskovali tla, podstrešni, stanovanjski in cestni prah ter trdne delce nakopičene v snegu in delce v zraku. Opredelili smo lastnosti obravnavanih materialov in geokemične značilnosti Maribora ter vpeljali analizo trdnih delcev v zraku s SEM/EDS. Prevladujoč mineral v tleh je kremen (geogen vpliv), v cestnem prahu dolomit (zimsko posipanje cest) in v podstrešnem prahu sadra, ki je najverjetneje sekundarnega nastanka. Analiza vsebnosti 65 elementov v tleh in vseh treh tipih prahov je pokazala, da se ti materiali po kemični sestavi medsebojno močno razlikujejo. Prevladujoč antropogen izvor smo v vseh materialih, z izjemo stanovanjskega prahu, pripisali Cd, Cu, Pb, Sb, Sn in Zn. Dodatno so v posameznih materialih pretežno antropogenega izvora še nekateri drugi PSE. Na dveh industrijskih območjih (Melje in Tezno) so vsebnosti PSE običajno najvišje, zato predvidevamo, da so večinoma posledica pretekle in sedanje kovinske industrije. V primerjavi s tlemi, so vsebnosti PSE višje v prahovih, kar je deloma posledica razlik v njihovem nastanku in v fizikalno-kemičnih lastnostih, vpliva antropogenih virov ter različnega zadrževalnega časa materialov. Podstrešni prah odraža zgodovinske vplive, cestni prah predvsem današnje vplive industrije in prometa ter stanovanjski prah vplive znotraj stanovanj. Z analizo prahov in delcev v snegu ter zraku s SEM/EDS smo ugotovili, da izmed delcev s PSE v vseh materialih prevladujejo oglati Fe-oksidi. Samo na industrijskem območju Melje se pojavljajo Cu-Zn ostružki, ki najverjetneje izvirajo iz livarne in Fe-Cr (Cu, Mn, Ni) ostružki, najverjetneje iz tovarne kovinskega pohištva ter livarne. Za Tezno so značilni predvsem visoki deleži Fe-oksidov in kroglastih Fe-oksidov, pogosto z nizkimi vsebnostmi Mn in drugih PSE. Glede na rezultate, kemična sestava stanovanjskega prahu odraža predvsem vire znotraj stanovanj in manj zunanje vplive. Izmed notranjih virov smo najbolj jasno prepoznali uporabo vžigalnikov v stanovanjih v katerih stanovalci kadijo, kar se odraža v visokih vsebnostih Ce, Fe in La ter pojavljanju Fe-Ce-La-O kroglic. Biodostopni deleži (BAF) PSE se močno razlikujejo med različnimi elementi, vzorci in materiali. V tleh, cestnem in podstrešnem prahu so večinoma večji v želodčni fazi kot v želodčno-črevesni. Za stanovanjski prah velja obratno. Med najbolj biodostopnimi PSE v želodčni fazi so Cd, Cu, Pb in Zn, katerih povprečni BAF je pogosto nad 40 %, ter v želodčno-črevesni As, Cd, Cu in Ni.
Ključne besede: urbana geokemija, trdni delci, potencialno strupeni elementi, biodostopnost, tla, podstrešni prah, stanovanjski prah, cestni prah, SEM/EDS
Objavljeno v DiRROS: 03.03.2022; Ogledov: 334; Prenosov: 115
URL Povezava na celotno besedilo

The environmental impact of historical Pb-Zn mining waste deposits in Slovenia
Miloš Miler, Špela Bavec, Mateja Gosar, 2022, izvirni znanstveni članek

Povzetek: Mining waste deposits (MWDs) represent significant and constant pollution source for the environment worldwide, thus it is very important to identify and diminish their environmental impacts. The aim of this study was to determine long-term environmental impacts and their temporal variations of MWDs in Pb–Zn mining districts in Slovenia and assess stability of potentially harmful element (PHE)-bearing phases in stream water. The results showed that investigated MWDs are important source of PHEs in stream sediments and that PHEs mostly occur as fine-grained and liberated PHE-bearing ore minerals. MWDs have generally stronger impact on sediments of smaller streams draining MWDs and main streams close to their confluences, however, fine-grained PHE-bearing material is transported along major watercourses over long distances causing regional pollution. Main ore minerals are mostly soluble in stream water. However, measured PHE leaching potential of MWDs is negligible. PHE levels in stream waters are thus low, demonstrating that drainage of MWDs predominantly contributes to PHE pollution in solid particulate form. Possible long-term remediation solution that would reduce environmental impact is recovery of metals from fine grain size fractions of MWDs, which could become an effective practice in sustainable management of historical MWDs. However, further studies of MWDs’ secondary resource potential, processing technology and evaluation of environmental aspects of extraction are needed.
Ključne besede: metals, stream sediment, stream water, characterisation, mineral solubility
Objavljeno v DiRROS: 03.03.2022; Ogledov: 247; Prenosov: 122
.pdf Celotno besedilo (19,64 MB)

Towards a holistic approach to the geochemistry of solid inorganicparticles in the urban environment
Martin Gaberšek, Mateja Gosar, 2021, izvirni znanstveni članek

Povzetek: Airborne particulate matter (PM) has a major impact on the biogeochemical cycles of chemical elements in theurban environment. Anthropogenic-derived PM emissions are the cause of some of the most severe environmen-tal and health problems. The presented study aims to improve our knowledge of PM dynamics by introducing amulti-media, multi-analytical and multi-elemental holistic approach to geochemical studies of inorganic PM inthe urban environment. The importance of the holistic approach is highlighted and its application in a casestudy of Maribor (Slovenia) is presented. The chemical composition and individual particulate characteristicsof street, attic and household dust were determined and compared with the characteristics of airborne PM,and PM deposited in snow, together with the chemical composition of the soil. We found that the mineralogicaland chemical composition and the individual solid particle characteristics of the studied media differ consider-ably. Nevertheless, minerals of geogenic origin are present in all media. The highest levels of potentially toxic el-ements (PTEs) in all media, except household dust, are typical for industrial areas. Street dust primarily reflectsthe influence of winter road maintenance and industrial activities, while characteristics of household dust arepredominantly influenced by indoor activities and properties of dwellings. The comparison of the chemical com-position of attic and street dust indicates that emissions of As, Cd, Pb, S and Zn were higher in the past. The char-acterisation of airborne PM and PM deposited in snow is essential for the identification of the mostrecentsourcesof PTE-bearing particles. Several industrial sources and the fate of some particle types in the environment havebeen determined based on thefindings of the SEM/EDS analyses. This study confirms that various environmentalmedia are carriers of diverse geochemical information and highlights the importance of a holistic approach ingeochemistry of PM in urban areas.
Ključne besede: Street dust, attic dust, household dust, airborne particulate matter, potentially toxic elements, SEM/EDS
Objavljeno v DiRROS: 06.01.2021; Ogledov: 1251; Prenosov: 542
.pdf Celotno besedilo (2,91 MB)

Iskanje izvedeno v 0.54 sek.
Na vrh