Geochemical Characteristics of the Mechanism of the Interaction of Neutral Technogenic Stream with Natural Water of the Salair Ore Field
Geochemical investigation of the Ekaterininskiy brook draining the Salayr ore field from the temporarily abandoned culvert (Salair city, Kemerovo Region) was carried out. Changes of the overall composition of element concentrations in water and in bottom sediments in the brook under investigation, the Malaya Talmovaya river and the zone of their mixing were determined. Model chemical forms of element occurrence and the indices of saturation of mineral phases in solution were calculated. The major mechanisms of element deposition at the geochemical barrier were revealed. It was demonstrated that the interaction between the brook and river waters causes substantial changes of the basic ion composition in the mixing zone, the concentrations of heavy metals decrease substantially but the level of background values is not achieved. The main forms of the occurrence of zinc (as the pollutant of priority for the system under consideration) in the surface water of the Ekaterininskiy brook are sulphate and aquated complexes. In water and bottom sediments of the Malaya Talmovaya River, zinc is represented mainly by aqua ions and carbonate complexes. For all testing regions, iron occurs in the form of hydroxide complexes, which was confirmed by calculated saturation indices. The latter values showed that the waters of the brook and the river are supersaturated with respect to goethite FeOOH and ferrihydride Fe(OH)<sub>3</sub>, and the latter compounds promote sorption and co-precipitation of a number of heavy metals