Iskanje po repozitoriju

A+ | A- | | SLO | ENG

Povzetek: Moss biomonitoring was conducted in 2002, 2005, 2010, 2015 and 2020 to evaluate atmospheric mercury (Hg) deposition across N. Macedonia as part of a comprehensive survey of potentially toxic elements (PTEs). More than 70 samples of the dominant moss species Hypnum cupressiforme and Homalothecium lutescens were collected during the summer field campaigns. Mercury concentrations were determined using cold vapour atomic absorption spectrometry and inductively coupled plasma mass spectrometry (ICP-MS). The results revealed marked temporal fluctuations: median Hg content increased from 56 μg/kg in 2002 to 68 μg/kg in 2005, peaked at 93 μg/kg in 2010, then decreased to 84 μg/kg in 2015, and further to 52 μg/kg in 2020. Over the study period, Hg concentrations ranged from 10 to 595 μg/kg, with the highest variability observed in 2010. Spatial distribution maps and regional comparisons indicate that elevated Hg contents correspond predominantly to anthropogenic sources, particularly in industrialised zones and regions affected by mining and metallurgical activities. The 2020 dataset shows a significantly lower median value (52 μg/kg) compared to previous surveys, indicating a slight improvement in air quality, although local hotspots persist. These results highlight the importance of long-term moss biomonitoring as a cost-effective approach for tracking atmospheric mercury trends and informing national environmental policy.
Ključne besede: atmospheric mercury, moss biomonitoring, potentially toxic elements, ICP-MS, North Macedonia
Objavljeno v DiRROS: 09.01.2026; Ogledov: 382; Prenosov: 133
Celotno besedilo (2,56 MB)

Povzetek: The northern Adriatic Sea is well known for mercury (Hg) contamination mainly due to historical Hg mining which took place in Idrija (Slovenia). The formation of dissolved gaseous mercury (DGM) and its subsequent volatilisation can reduce the amount of Hg available in the water column. In this work, the diurnal patterns of both DGM production and gaseous elemental Hg (Hg0) fluxes at the water-air interface were seasonally evaluated in two selected environments within this area, a highly Hg-impacted, confined fish farm (VN: Val Noghera, Italy) and an open coastal zone less impacted by Hg inputs (PR: Bay of Piran, Slovenia). A floating flux chamber coupled with a real-time Hg0 analyser was used for flux estimation in parallel with DGM concentrations determination through in-field incubations. Substantial DGM production was observed at VN (range = 126.0–711.3 pg L−1) driven by both strong photoreduction and possibly dark biotic reduction, resulting in higher values in spring and summer and comparable concentrations throughout both day and night. Significantly lower DGM was observed at PR (range = 21.8–183.4 pg L−1). Surprisingly, comparable Hg0 fluxes were found at the two sites (range VN = 7.43–41.17 ng m−2 h−1, PR = 0–81.49 ng m−2 h−1), likely due to enhanced gaseous exchanges at PR thanks to high water turbulence and to the strong limitation of evasion at VN by water stagnation and expected high DGM oxidation in saltwater. Slight differences between the temporal variation of DGM and fluxes indicate that Hg evasion is more controlled by factors such as water temperature and mixing conditions than DGM concentrations alone. The relative low Hg losses through volatilisation at VN (2.4–4.6% of total Hg) further confirm that static conditions in saltwater environments negatively affect the ability of this process in reducing the amount of Hg retained in the water column, therefore potentially leading to a greater availability for methylation and trophic transfer.
Ključne besede: Idrija mercury mine, mercury evasion, fish farm, flux chamber, water-air exchange, Adriatic Sea, Idrijski rudnik živega srebra, ribogojnica, pretočna komora, izmenjava voda-zrak, Jadransko morje
Objavljeno v DiRROS: 12.07.2024; Ogledov: 1175; Prenosov: 641
Celotno besedilo (6,86 MB)
Gradivo ima več datotek! Več...

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: 1714; Prenosov: 798
Povezava na celotno besedilo