Reduction of nitrogen discharges in mining processes and mitigating its environmental impact – miNing I

Purpose and goal
The overall aim of miNing is to reduce nitrogen concentrations in the outflow of mining areas so that the nitrogen concentrations in recipients meet the requirements of national and international agreements and laws. The sub-projects work on gaining this goal, but final results have not been received, yet. Instead, these will be part of (in agreement with Vinnova and the involved mining companies) part 2 of the project (dnr 2014-01134).

Structure and implementation
miNing is divided into three sub-projects: 1) bioreactor and waste rock deposit, 2) Nitrogen reduction in sedimentation and clarification ponds and 3) Wetlands. Each sub-project applies a research approach that is designed to fulfill the aim of miNing and that is adapted to the natural prerequisites. Important methods include laboratory and field (in situ) studies where target parameters are followed up and where environmental variables are manipulated to optimize nitrogen reduction.

Expected results
In most of the sub-projects, no final results have been received, yet. Data from part 1 (this report) are currently evaluated in part 2 of the project (dnr 2014-01134). However, in the wetland sub-project, we can already now state that a) the nitrogen reduction potential varies among wetland species and b) the dominating pathway (uptake or release of nitrogen gas) is species dependent. These results are highly important for the design of future wetlands.