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.
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•Direct investigation of 24 h gaseous mercury fluxes in highly impacted coastal area.•Floating flux chamber coupled with a real-time spectrometer was used in the field.•Notable Hg dark reduction and evasion during night at impacted confined fish farm.•Relevant emissions due to turbulence at open coastal site despite low Hg levels.•Static conditions can increase Hg residence time and availability in water column.
The production of glass foams obtained by recycling post-consumer glass and textile industry processing waste is presented. The mechanical, thermal and acoustic properties were characterized as a ...function of process temperature and time. The results showed that it is possible to produce glass foams with thermal and acoustic insulation properties from a mixture consisting of 96.5% of glass waste, 1% of textile waste and 2.5% of manganese dioxide, processed at temperatures between 800 and 900 °C for a time between 30 and 90 min. The samples had density in the range of 200-300 kg m
, porosity of 87-92%, thermal conductivity of 85-105 mW m
K
, noise-reducing factors of 0.15-0.40 and compressive strength of 1.2-3.0 MPa. Although their insulation performance was not as outstanding as that of polymer foams, these materials can emerge as competitive candidates for applications requiring non-flammability and high-temperature load bearing capacity in combination with low weight, mechanical strength, and thermal and acoustic insulation properties. The use of secondary raw materials (which accounted for 97.5% by weight of the synthetic blend) limits the energy required compared to that needed for the extraction, transportation and processing of primary raw materials, making these foams attractive also in terms of environmental footprint.
Decommissioned mines represent a worldwide concern due to the potential long-term effects related to the dispersion of potentially toxic elements (PTEs) in the environment. In this study, 176 water ...samples were collected in the period 2018–2021 at the carbonate-hosted Pb-Zn Raibl mine which is affected by neutral mine drainage (NMD). The post-flotation tailings are the main source of PTEs (Zn, Pb and especially Tl) in the river drainage system. Compared to other dissolved PTEs (Zn, Pb, Cd), Tl was found to be more mobile, reaching concentrations up to 120 μg L−1 in waters flowing in the tailings impoundments. Modelling results suggest that Tl is mainly present in the Tl(I) ionic and mobile form thus suggesting that relevant natural attenuation processes for this element are not expected in the investigated area. In contrast, Zn and Pb attenuation pathways appeared to be governed by pH-dependent speciation and sorption processes, whereas elevated Zn concentrations were likely also limited by hydrozincite precipitation. Metalloids such as As and Sb were almost entirely released into the slightly alkaline waters of the mine drainage system, which are generally characterised by longer residence time or standing waters whereas As and Sb concentrations were negligible in the tailings-seepage waters. However, intense rainy events may increase PTE concentrations of one order of magnitude, especially in the tailings impoundment groundwater as a result of a rise in the water table, and PTE total dissolved loads of three orders of magnitude, in the main stream during high flow events, thus representing the most critical factor in regulating the remobilisation and downward dispersion of PTEs in the river drainage system.
•176 water samples were collected at the Pb-Zn Raibl mine site from 2018 to 2021.•Dispersion of potentially toxic elements persists 30 years after shutdown.•The post-flotation tailings represent the main sources of Thallium in waters.•Intense rainy events may notably increase PTEs and total dissolved loads.•Arsenic was found to be more mobile in gallery seepages.
The decommissioned fahlore Cu-Sb(-Ag) mine at Mt. Avanza (Carnic Alps, Italy) is a rare example of exploited ore deposits, as the tetrahedrite (Cu
6
Cu
4
(Fe,Zn)
2
Sb
4
S
13
) is the main ore mineral ...found. This multi-compartmental geochemical characterisation approach provides one of the first case studies regarding the geochemical behaviour and fate of Hg, Sb, As, Cu, and other elements in solid and water matrices and of Hg in the atmosphere in an environment affected by the mining activity of a fahlore ore deposit. Elevated concentrations of the elements (Cu, Sb, As, Pb, Zn, Hg) associated with both (Zn-Hg)-tetrahedrite and to other minor ore minerals in mine wastes, soils, and stream sediments were observed. Concentrations in waters and stream sediments greatly decreased with increasing distance from the mining area and the I
geo
index values testify the highest levels of sediment contamination inside the mine area. Thallium and Ge were associated with the “lithogenic component” and not to sulfosalt/sulphide minerals. Although mine drainage water often slightly exceeded the national regulatory limits for Sb and As, with Sb being more mobile than As, the relatively low dissolved concentrations indicate a moderate stability of the tetrahedrite. The fate of Hg at the investigated fahlore mining district appeared similar to cinnabar mining sites around the world. Weak solubility but the potential evasion of gaseous elemental mercury (GEM) into the atmosphere also appear to be characteristics of Hg in fahlore ores. Although GEM concentrations are such that they do not present a pressing concern, real-time field surveys allowed for the easy identification of Hg sources, proving to be an effective, suitable high-resolution indirect approach for optimising soil sampling surveys and detecting mine wastes and mine adits.
Gaseous exchanges of mercury (Hg) at the water–air interface in contaminated sites strongly influence its fate in the environment. In this study, diurnal gaseous Hg exchanges were seasonally ...evaluated by means of a floating flux chamber in two freshwater environments impacted by anthropogenic sources of Hg, specifically historical mining activity (Solkan Reservoir, Slovenia) and the chlor-alkali industry (Torviscosa dockyard, Italy), and in a pristine site, Cavazzo Lake (Italy). The highest fluxes (21.88 ± 11.55 ng m−2 h−1) were observed at Solkan, coupled with high dissolved gaseous mercury (DGM) and dissolved Hg (THgD) concentrations. Conversely, low vertical mixing and saltwater intrusion at Torviscosa limited Hg mobility through the water column, with higher Hg concentrations in the deep layer near the contaminated sediments. Consequently, both DGM and THgD in surface water were generally lower at Torviscosa than at Solkan, resulting in lower fluxes (19.01 ± 12.65 ng m−2 h−1). However, at this site, evasion may also be limited by high atmospheric Hg levels related to dispersion of emissions from the nearby chlor-alkali plant. Surprisingly, comparable fluxes (15.56 ± 12.78 ng m−2 h−1) and Hg levels in water were observed at Cavazzo, suggesting a previously unidentified Hg input (atmospheric depositions or local geology). Overall, at all sites the fluxes were higher in the summer and correlated to incident UV radiation and water temperature due to enhanced photo production and diffusivity of DGM, the concentrations of which roughly followed the same seasonal trend.
The Gulf of Trieste (Northern Adriatic Sea, Italy) is the coastal area of the Mediterranean Sea most highly contaminated by mercury (Hg) due to fluvial inputs from the Isonzo/Soča River system, ...draining over 500 years’ worth of cinnabar extraction activity from the Idrija mining district (Western Slovenia). The aim of this research is to investigate the concentration of Hg in hair samples taken from the general population of the Friuli Venezia Giulia (FVG) Region coastal area, as a marker of chronic exposure to Hg. Three hundred and one individuals — 119 males and 182 females — were recruited by convenience sampling in Trieste in September 2021. An amount of approximately 100 mg of hair was collected from the occipital scalp of each participant to measure the respective Hg concentrations (expressed as mg/kg). Moreover, participants completed a self-report questionnaire collecting extensive socio-demographic and life-style information. A multiple linear regression analysis was employed to investigate factors associated with increased levels of Hg concentration in hair. A mean Hg concentration in hair of 1.63 mg/kg was found, slightly above the 1.0 mg/kg threshold recommended by the WHO for pregnant women and children, although still well below the no observed adverse effects level (NOAEL) of 10 mg/kg. Among respondents, 55.6% showed a Hg concentration in hair > 1 mg/kg, 22.9% > 2 mg/kg, and 2 participants exhibited Hg levels > 10 mg/kg. The adjusted mean hair Hg level increased in those subjects who reported a preference for shellfish/crayfish/mollusks (RC = 0.35; 95%CI: 0.16; 0.55), whereas it decreased in those who reported a preference for frozen fish (RC = -0.23; 95%CI: − 0.39; − 0.06). Though a risk alert for Hg exposure for coastal residents from FVG is deemed unnecessary at this time, it is recommended that pregnant women limit their ingestion of locally caught fish to < 4 servings/month.
When mines are decommissioned, tailings piles can act as sources of contamination for decades or even centuries. Tailings, which usually contain high concentrations of metals and trace elements, can ...be reprocessed for a secondary recovery of valuable elements with an innovative approach to a circular economy. This study offers new results for tailings ponds characterisation and chemical content prediction based on an integrated geophysical-geochemical approach. The study of the Raibl Pb-Zn tailings impoundment was done using bulk chemical analysis on borehole samples, Electrical Resistivity Tomography surveys, and Ground Penetrating Radar measurements. We found valuable and statistically significant correlations between the electrical resistivity of the mining impoundments and the metal distribution, thus providing a practical opportunity to characterise large volumes of metal-bearing tailings. In particular, these results can be useful to aid in the development of environmental monitoring programs for remediation purposes or to implement economic secondary recovery plans.
Portable X-ray fluorescence (pXRF) is one of the main geochemical techniques employed in multi-elemental analysis screening for contaminated sites management. As the confidence of pXRF analyses are ...matrix-specific, efforts are made to provide studies of pXRF quality on different geochemical datasets, focusing on less investigated elements such as mercury (Hg) and antimony (Sb), to help both new and experienced users. The analysis of environmental solid samples from two decommissioned mining sites in NE Italy, characterised by Pb-Zn and (Hg-rich) Cu-Sb ore deposits, were prepared with two different protocols and compared with traditional destructive analyses. Sample composition was found strictly dependent to the occurrence of false positives and overestimation at low concentrations. In contrast, milling the sample did not produce major variations in the overall quality. Lead (Pb), Sb, and Zn reached the definitive data quality in at least one of the two datasets. Consequently, as far as a thorough QA/QC protocol is followed, pXRF can rapidly produce chemical data that is as accurate as that produced by destructive standard laboratory techniques, thus allowing to identify potential sources of contamination that could be reprocessed for the extraction of valuable elements and mitigating the dispersion of contaminants and ecological or health risks.
This paper explores the development of pottery technology in the Trieste Karst region (North-East Italy) from the Neolithic to the Early Bronze Age (EBA). It also seeks to identify cultural links ...with other areas by examining potentially imported vessels. Archaeometric analyses (X-ray diffraction and optical microscopy) reveal significant differences between Neolithic ceramics (Danilo–Vlaška Group) and the majority of Late Copper Age (LCA)/Early Bronze Age (EBA) pottery (primarily associated with the Ljubljana Culture and a few with the Cetina Culture). Neolithic pottery displays consistent characteristics across all vessel types, including coarse grain, prevalent sparry calcite temper, and the absence of grog. In contrast, most LCA and EBA vessels exhibit distinct features such as very fine-grained paste, no sparry calcite, notable use of grog temper, higher quartz, muscovite, and flint content. Notably, from a technological perspective, the analyzed Cetina vessels bear a strong resemblance to the majority of LCA ceramics. The differences between Neolithic and LCA/EBA vessels clearly suggest the use of new raw materials, recipes, and techniques, likely reflecting changes in cultural and social contexts and potential connections with the core area of the Ljubljana Culture.
Mercury (Hg) is a global pollutant, being highly persistent in the atmosphere, in particular gaseous elemental mercury (GEM), which can easily be emitted and then transported over long distances. In ...the Gulf of Trieste (northern Adriatic Sea, Italy), contamination by Hg is well characterised but little is known regarding the concentrations, sources and fate of GEM in the atmosphere. In this work, discrete measurements of GEM were recorded from several sites at different times of the year. The database is consistent with temporal night-day variations monitored using a continuous real-time device. The meteorological conditions were collected as ancillary parameters. GEM levels varied from <LOD (2.0 ng m−3) to 48.5 ng m−3 (mean 2.7 ng m−3), with no significant differences found among sites. A clear daily pattern emerged, with maximum values reached just after sunset. Air temperature, relative humidity, wind speed and direction were identified as the main micrometeorological factors influencing both the spatial and temporal variation of GEM. Our results show that average atmospheric GEM values are higher than the natural background of the Northern Hemisphere and will be useful in future selection regarding the most suitable sites to monitor atmospheric Hg depositions and fluxes from soil and water.
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