Metla Project 7207

Biological removal of nutrients from mine waters

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Duration: 2005-2008   Keywords: bioreactor, denitrification, explosives, microbes, mining, nitrification, nutrients, water
Research project group: Distinct projects 1 - Structure and function of forest ecosystems


The mining sector in important for the economy and labor market in Northern Finland. Nitrogen-based explosives used during mining are the major source of ammonia and nitrate in mine waters. In Lapland, mine water receiving streams and water bodies are small and vulnerable to eutrophication. The aim of KAIRA-project is to develop different treatment processes for the effective removal of total nitrogen in mine waters at low temperature.

The studied treatment processes for mine waters combine physical concentration of nutrients by reverse osmosis and biological removal of nitrogen via nitrification and denitrification. The biological removal of nitrogen from saline, heavy metal rich effluents at low temperature is cutting-edge technology. The parameters affecting the processes, e.g. temperature, heavy metal content and salinity, will be determined. Further, potential retardation (biosorption) of heavy metals in biofilms of the nitrifying and denitrifying bioreactors will be studied. Within the project, pilot-scale experiments are carried out at operating mine. Furthermore, the fate of ammonium and nitrate during mining activities will be monitored in respect to different explosives and working methods used at a mine.

Finally, the KAIRA-project aims to recommend an economical feasible BAT option for treatment of nutrient-containing mine waters in cold climate.

More about the KAIRA-project:


The final report of the project can be found from the Press releases, publications, posters page.

Project leader: Varmola, Martti
The Finnish Forest Research Institute, Rovanniemi Office, PL 16, FI-96301 ROVANIEMI, FINLAND
Phone: +358 29 532 4410

Other researchers: Häyrynen, Katri (2006), Karkman, Antti (2006), Kontio, Heidi (2006-07), Mattila, Katri (2005-07), Mettänen, Tarja (2005-07), Zaitsev, Guennadi (2005-07)

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Updated 12.06.2012