The Principality of Asturias, in north-western Spain, is a region with a long mining tradition and coal mining has been the economical motor of the region for centuries. However, nowadays around 200 mines are abandoned. Many of these mines were abandoned long before the introduction of any environmental regulations to control metal release, and nowadays, they still are one of the most significant pollution threats in Asturias causing environmental problems and health risks for the local population.
The DEMINE technology may offer an efficient and innovative solution to face this environmental problem in Asturias, since results obtained until the date from the two demonstration sites have indicated high metal removal efficiencies from mining effluents.
In order to spread the environmental problem targeted in the LIFE DEMINE project, its consequences in Asturias, and the potential of the DEMINE technology to face them, a specific didactic activity was performed in the framework of Action B.5.
Specifically, this didactic activity was addressed to students from the Santa Cristina de Lena high-school, located in Pola de Lena, a small town in Asturias, closed to the “Soterraña” abandoned mine. “La Soterraña” is an abandoned mercury mine causing high arsenic concentrations in waters downstream the mine. Until the date, no major intervention measures have been applied.
This didactical activity was performed in two consecutive days (9 and 10 October 2021). On the first one, the Government of the Principality of Asturias introduced the activity and the environmental problem caused by abandoned mines in Asturias. After that, researchers from the UVIC explained the main ecological impacts caused by mining effluents in freshwater ecosystems. Then, the students visited “La Soterraña” abandoned mine and collected water samples from different streams downstream it.
During the second day, the water samples collected during the visit to the “Soterraña” mine were analyzed in the high-school’s lab. The total arsenic concentration and the water temperature and conductivity were determined by the students, using multiparametric probes and testing kits. Results from these analyses revealed high arsenic concentrations (aprox. 70 mg/L) in water near the mine, while this concentration decreased downstream. Then, using the same water samples collected and analyzed, ELENTEC tested the efficiency of the DEMINE technology in reducing the metal concentration on them. To do that, ELENTEC constructed a small prototype of the technology, where the different steps involved on it were clearly evidenced in order to show students its functioning and the metal removal. The water samples obtained at the end of this process were analyzed again and a clear arsenic removal (95%) was observed, proving the efficiency of the DEMINE technology to treat this effluent from “La Soterraña” abandoned mine. Finally, researchers from the UVIC explained the method used in the project to assess and guarantee the overall sustainability of the technology and, together with the students, the DEMINE tool was applied to assess the sustainability benefits provided by the technology in the specific case of treatment the mining effluent from “La Soterraña” abandoned mine.
