The ultimate source of most of nitrogen cycling at a mine site is the ammonium nitratebased 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.
NITREM was a three-year innovation project (2018-2021) funded by EIT RawMaterials with the aim of developing a service that combines geomorphic landscape design for waste rock deposits with a nitrate-removing bioreactor technology that reduces nitrogen levels in waste rock leachate. Geomorphic landform design has been identified as Best Available Technique (BAT) in the European Union and the bioreactor technology development has been driven by EU’s Water Framework Directive. Applying the NITREM service enables the industry to meet current and future discharge requirements.
The NITREM project consortium consisted of Uppsala University, WSP Sverige AB, Cedervall Arkitekter, Agencia Estatal Consejo Superior de Investigaciones Cientificas, Boliden Mineral, LKAB, LTU Business and the Swedish University of Agricultural Sciences.