Processes of formation of waste waters and measures to minimize their impact on the hydrosphere (on the example of the Levikhinsky mine, Middle Urals)

Relevance. There is a continuous formation of acidic waste waters at the Levikhinsky mine, while negatively affecting the hydrosphere for almost a hundred years. Aim. To establish the relationship between the composition of the waste rock and the waste water in order to justify measures to minimize the waste water impact on the environment. Objects. Waste water formed in the dump of the Levikhinsky copper and cobalt mine. Methods. The work is based on the results of hydrochemical sampling of waste water and chemical sampling of dump rocks, determination of compliance of water quality and dump rocks with the established regulatory requirements; collection, analysis and processing of hydrological and statistical information; literature search and analysis of the best available technologies to prevent pollution of the hydrosphere from objects of accumulated harm. Results. There are more than a dozen waste dumps with a total area of 30 hectares and a volume of 1,7 million m3 at the Levikhinsky copper-pyrite deposit (Middle Urals). At the base of the largest of them, for several decades, acidic bottom waters are discharged, the flow rate of which exceeds 1 thousand m3/day in floods. Water composition is sulfate, predominant cations are iron and aluminum, mineralization varies from 13 to 52 g/dm3, pH reaches 1,9. The concentrations of elements in the dump water depend on the season and climatic conditions. The rocks of the dump are represented mainly by quartz, feldspars and clay minerals; high concentrations of sulfur, copper, zinc, arsenic, cobalt and cadmium are observed. The amount of ecological and economic damage as a result of intake of waste water is more than 95 million rubles per year. To minimize the impact of waste waters on the environment, the authors have considered two directions: dump remediation and waste water treatment, and performed a comparative analysis of their advantages, disadvantages and costs for the implementation of environmental protection measures.