Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Portuguese São Domingos mine generates acidic water following 43 years of inactivity

10.02.2009
Located five kilometers from the Spanish border, the Portuguese São Domingos mine, abandoned since 1966, continues to pollute the river ways that flow into Chanza dam, the largest drinking water reservoir in the province of Huelva, according to scientists from the University of Huelva. The new study shows that oxidation and the dissolving of sulfurs are processes that remain active today, so the researchers are asking that solution plans be put in place.

The Portuguese São Domingos mine is located in the Iberian Pyrite Belt along with other mines located on the Spanish side, such as Río Tinto or Almagrera, Huelva. The mine abounds in highly contaminating waste, such as smelting dregs and ash. Active between 1857 and 1966, over time it has generated "extremely" acidic drainage due to the oxidation of sulfuric waste.

According to Antonio M. Álvarez-Valero, lead author of the study published recently in the journal Environmental Geology and currently a researcher at the Andalusian Institute of Earth Sciences (a University of Granada - CSIC joint center), "the fundamental concern from the environmental point of view deriving from this waste oxidation is the generation of acidic waters".

And the acidic discharge from São Domingos affects Chanza dam, the largest drinking water reservoir serving Huelva, because the pollutants undergo "a relative attenuation".

To evaluate the environmental impact and determine the level of acidification of some components, the study presents a characterization of the mineralogical, geochemical and physical properties of the mining waste from the São Domingos district. "We have established, through a later work, the potential risk of moving the toxic metals in this waste, and their possible incorporation into the food chain", Álvarez-Valero explains to SINC.

Although the mine is abandoned, it remains active "from the point of view of contamination". The researcher says that the contaminating impact of the mine is renewed in annual cycles. During the wet or raining periods, the contaminating elements "re-dissolve and once again generate acidity", Álvarez-Valero points out.

The analysis shows that "the massive presence of sulfurs in São Domingos in some of the waste ensures a continuous, annual generation of acidic mine drainage", the researcher confirms.

The mine, which is considered medium in size compared to others, is exposed to "a remarkable" volume of waste: 25 Mm3. Although a large part of this waste is inaccessible because it is located beneath the town of São Domingos, "its high acidification potential represents a threat for environmental pollution", the scientist says.

Faced with this situation, the researchers say that the methodical sequence of this study should be applied to other mines in the same area, such as Caveira, Lousal, Aljustrel, in the south-east of Portugal, and Tharsis, La Zarza, Peña del Hierro, Almagrera or Río Tinto, in Huelva, where research projects are already underway.

The São Domingos mining district was active between the 19th and 20th centuries, but "mining there goes back to pre-Roman times", says Álvarez-Valero. In the abandoned or fossil mining areas, the largest sources of soil and surface water contamination come from the leaching (washing) of metals and metalloids from waste rich in sulfur (such as pyrite).

SINC Team | alfa
Further information:
http://www.plataformasinc.es

More articles from Ecology, The Environment and Conservation:

nachricht Safeguarding sustainability through forest certification mapping
27.06.2017 | International Institute for Applied Systems Analysis (IIASA)

nachricht Dune ecosystem modelling
26.06.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

Im Focus: Laser-cooled ions contribute to better understanding of friction

Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision

Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

Leipzig HTP-Forum discusses "hydrothermal processes" as a key technology for a biobased economy

12.07.2017 | Event News

 
Latest News

Researchers create new technique for manipulating polarization of terahertz radiation

20.07.2017 | Information Technology

High-tech sensing illuminates concrete stress testing

20.07.2017 | Materials Sciences

First direct observation and measurement of ultra-fast moving vortices in superconductors

20.07.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>