1,720,999 research outputs found
Seasonal variability of harmful components in different aqueous fractions in natural waters
No full textAntimony Occurrence and Mobility in an Area Impacted by a Former Stibnite Mine in Sardinia (Italy)
No full textLa sistematica isotopica dello Sr come tracciante dei circiuti idrologici: il bacino del Flumendosa (Sardegna Meridionale, Italia).
No full textLa sistematica isotopica dello Sr come tracciante dei circiuti idrologici: il bacino del Flumendosa (Sardegna Meridionale, Italia).
No full textAntimony contamination of surface water at abandoned Sardinian mine sites
No full textThe element antimony raises much concern from both toxicological and
environmental viewpoints. The World Health Organization has established a guideline value of 20 μg/L Sb for drinking water, while the Italian legislation indicates a lower value (5 μg/L Sb). Antimony is ubiquitously present throughout the environment as a result of both natural and human processes. Particularly high concentrations of Sb may occur in water draining abandoned mining sites and in
adjacent soils.
This study is aimed to assess the Sb occurrence, and dispersion in aquatic systems
located in the Sarrabus-Gerrei mining district, south-eastern Sardinia (Italy). In
this area, Sb ores have been mined till the 1980s. Thereafter, mines were closed
and mining residues were abandoned without intervention to mitigate the
environmental impact. Surface waters downstream of the mine show high concentrations of Sb (up to 1500 μg/L) and As (up to 230 μg/L). Contamination extends several kilometers downstream of the mine and affects the Flumendosa river, which water is used for irrigation and domestic purposes. Antimony
concentrations in the Flumendosa water exceed 5 times the Italian standard for
drinking water.
The Regional Government has recently recognized this site as a priority in the
remediation plan for contaminated sites. The results derived from this study can
give a valuable contribution in the correct management and preservation of
aquatic bodies, and also in suggesting the appropriate actions able to mitigate
environmental effects in Sb-contaminated aquatic systems
Antimony dispersion at an abandoned mine site in Sardinia
No full textAlthough several researches on Sb occurrence and fate
have been carried out so far, the geochemical behavior of Sb in
supergene environments is not fully understood. This study
aims at investigating the Sb occurrence and dispersion in the
soil-water-plant system in the abandoned antimony mine of Su
Suergiu (Sardinia, Italy) and surrounding areas
Residual fibrous tissue floating in the right atrium after percutaneous pacemaker lead extraction: An unusual complication early detected by intracardiac echocardiography
No full textExtraction of pacemaker leads represents the optimal therapy in patients with endocarditis involving the pacemaker leads. The percutaneous approach is becoming popular. However, complications of percutaneous extraction are not rare and incomplete removal of the vegetations with embolization in the pulmonary arteries has been described. This case report describes for the first time a case of incomplete removal of the fibrous sheath covering the lead, with residual tissue floating in the right atrium after pacemaker/ICD extraction. ICE monitoring was essential for early detection and correct diagnosis of this complication. © 2007 Elsevier Ireland Ltd. All rights reserved
From acid-rock drainage to acid-mine drainage: extreme contamination in waters at the Furtei Au-mine (Sardinia, Italy)
Full text linkThe weathering of sulfide-bearing mineral deposits, exposed either by natural erosion or by mining to
oxygen and water, can produce natural acid-rock drainage (ARD) and mining-related acid-rock drainage (acid
mine drainage, AMD), respectively. The composition and extent of acid drainage is highly variable, depending
on many factors, such as the composition of ore bodies and related host rocks, climate, mining operations and
processing (Nordstrom and Alpers, 1999). Due to the low pH and high concentrations of contaminants, acid
drainages can severely degradate surface and groundwater systems, as well as soils.
At Furtei (Sardinia, Italy), a high-sulfidation epithermal gold deposit consists of pyrite and enargite with
minor amounts of luzonite, tennantite, and chalcocite. The oxidized cap mainly consists of iron oxy-hydroxides,
gypsum, jarosite, halotrichite and scorodite. The gold deposit was exploited by open pit from 1997 to 2003.
The Au and Ag were recovered from oxidized ores by cyanidation. Sulfide ores were processed by flotation to
recover Cu concentrates. Total production was about 4 t of Au, 6 t of Ag, and 1500 t of Cu (Cidu et al., 2013).
Pre-mining conditions showed waters (flow <0.1 L/s) with pH down to 2.3, a typical example of ARD
characterized by high salinity (26 g/L) with predominant sulfate (20 g/L) and very high amounts of dissolved
contaminants (in mg/L): Al 2000, Fe 1700, Mn 35, Cu 29, Zn 11, Ni 4, Co 3, Cr 1, As 0.4, and Cd 0.1 (Cidu
et al., 1997).
During exploitation and after the mine closure, the number of sites with contaminated water increased.
Contaminated waters showed pH and chemical compositions similar to those observed under pre-mining
conditions, but much higher concentrations of Cu, Zn, As and Cd, respectively up to 180, 97, 5, and 1.7 mg/L
(Da Pelo et al., 2009; Cidu et al., 2013). The seepage from the tailings impoundment is collected in a well
and back pumped into impoundment. The highly contaminated water in the open pits and drainages from the
pyrite-rich waste dumps may flow downstream from the mine under heavy rain periods and pose a hazard to
agricultural areas
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