Project duration: 1 January 2018 – 31 March 2021


The ultimate source of most of the nitrogen cycling at a mine site is the ammonium nitrate-based explosives used in the excavation of the mine. Waste rock, a by-product from the excavation of non-metalliferous rock in mining activities, often contains adsorbed nitrogen compounds (ammonium and nitrate) that are residues from the detonation of the explosives. Once the waste rock is deposited on the ground surface, the percolation of rain and snowmelt through the deposit will leach the nitrogen compounds, potentially impacting local recipients.

The solution (technology)

NITREM establishes a service for the passive removal of nitrogen from waste rock leachate with a bioreactor technology, in conjunction with the consideration of long-term waste rock management. Compared with alternative removal methods, the bioreactor can treat low and variable nitrogen loadings while expending little energy.

Technology development has been driven by EU’s Water Framework Directive and will enable the industry to meet current and future discharge requirements. The outcome is a low cost and low maintenance technology that is ready for market introduction and customer testing.

In addition to base metal mining, the up-scaled technology is expected to have a significant impact on the rock quarrying sector, where there are similar issues with nitrogen discharges. It is our ambition that the bioreactor system will become BAT in the European raw materials sector for the removal of nitrate from waste rock drainage.


  • Uppsala University, Sweden (Lead partner)
  • Spanish National Research Council (CSIC), Spain
  • AL Miljökonsult AB, Sweden
  • Boliden Mineral AB, Sweden
  • Cederwall arkitekter AB, Sweden
  • LTU Business AB, Sweden
  • Luossavaara-Kiirunavaara AB (LKAB), Sweden
  • Swedish University of Agricultural Sciences (SLU), Sweden
  • WSP Sverige AB, Sweden

For more information, please visit the official website of the project.