An important problem in soil magnetometry is unraveling the soil contamination signal in areas with multiple emitters. Here, geophysical and geochemical measurements were performed at four sites on a north - south transect along the Pasvik River in the Barents Region (northern Norway). These sites are influenced by depositions from the Bjørnevatn iron mine and a Ni-Cu smelter in Nikel, Russia. To relate the degree and type of pollution from these sources to the corresponding magnetic signal, the topsoil concentrations of 12 Potentially Toxic Elements (PTEs) (As, Cd, Co, Cr, Cu, Fe, Mo, Ni, Pb, Se, Ti, Zn), were determined, magnetic hysteresis parameters and thermomagnetic properties were measured. In situ magnetic low-field susceptibility decreases from north to south with increasing distance from the iron mine. Relatively large magnetic multidomain grains of magnetite and/or titanomagnetite are responsible for the strong magnetic signal from the topsoil close to Bjørnevatn. These particles are related to increased enrichment factors of As, Mo and Cu, yielding high positive correlation coefficients with susceptibility values. At a site furthest away from the iron mine and located 7?km from the Ni-Cu smelter magnetic susceptibility values are much lower but significant positive correlations on the level of p?
Repparfjorden in northern Norway has been partly designated for submarine mine tailings disposal when the adjacent Cu mine re-opens in 2019. In order to increase sedimentation, the flocculant, Magnafloc10 is planned to be added to the mine tailings prior to discharge into the fjord. This study investigated the feasibility of reducing the Cu concentrations (375?mg/kg) in the mine tailings by applying electrodialytic extraction, including potential optimisation by adding Magnafloc10. In the acidic electrodialytic treatment (pH??12), Magnafloc10 reduced the extraction of Cu from 17% to 0.7%, due to the flocs remaining in the tailing slurries. The electric energy consumption per extracted Cu was similar in the acidic and alkaline electrodialytic treatments without the addition of Magnafloc10. In the alkaline electrodialytic treatment, the extraction of other metals was low (