EIT RawMaterials innovation project NITREM starts operations of the first full-scale denitrifying bioreactor for mine drainage treatment

On 19 September 2018, the first litres of nitrate-laden drainage water started to flow through a denitrifying bioreactor at LKAB Kiruna iron ore mine. The bioreactor, which is the first full-scale bioreactor system for the passive removal of nitrate from mine drainage, promotes the conversion of nitrate to harmless nitrogen gas. Nitrate is derived from the use of explosives in the underground mine, and environmental regulations require that LKAB reduce nitrogen discharges to the surface water environment.

The NITREM project has had an intense start-up period since April 2018 when a water collection system and a group of three bioreactors were designed at LKAB in Kiruna, Sweden. At present, the water collection system and one bioreactor are in operation; the remaining two bioreactors will be completed during the fall of 2018. The performance of the bioreactor will be monitored until the end of the project period in 2021.

The bioreactor construction is part of the Innovation (up-scaling project) NITREM that is primarily funded by EIT RawMaterials, the world’s largest Knowledge and Innovation Community in the raw materials sector. The objective of the NITREM (NITrogen REMoval from waste rock) project is to establish a process for the passive removal of nitrogen from waste rock leachate with a bioreactor technology, in conjunction with long-term waste rock management and sustainable landscape design. The technology development is driven by the EU Water Framework Directive and will enable the industry to meet current and future discharge requirements. An outcome of the project will be a low cost and low maintenance technology that is ready for market introduction and customer testing.

The NITREM project is led by Roger Herbert from the Department of Earth Sciences at Uppsala University. Other project partners are researchers from SLU and the Spanish state’s highest scientific council, CSIC, mining companies LKAB and Boliden, and consulting firms WSP and Cedervall Arkitekter.

My doctoral student Albin Nordström and I have worked in Kiruna for two years with a pilot-scale plant to remove nitrogen from process water. This bioreactor worked so well both for us and for LKAB that we decided to seek funding to develop a full-scale plant for the treatment of waste rock leachate.

Roger Herbert, Uppsala University

The NITREM project has been awarded funding for the 2018–2021 period. The budget for the project is an EUR 4.8 million, of which EUR 2.5 million will be financed by participating mining company LKAB where the rest of the funding will be provided by the EIT RawMaterials.

Members of the NITREM innovation project consortium:

  • 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

To learn more about the NITREM innovation project please visit the project website www.nitrem.eu