Open AccessRegularities of groundwater quality formation at the abandoned copper mines of Levikha ore field (Middle Urals, Russia)
Author(s) -
L. S. Rybnikova,
L. S. Rybnikova,
P. A. Rybnikov,
P. A. Rybnikov
Publication year - 2019
Publication title -
geohimiâ
Language(s) - English
Resource type - Journals
ISSN - 0016-7525
DOI - 10.31857/s0016-7525643282-299
Subject(s) - groundwater , geology , weathering , dilution , geochemistry , copper , mining engineering , hydrology (agriculture) , environmental science , chemistry , geotechnical engineering , physics , organic chemistry , thermodynamics
In the Urals region in recent decades, dozens of copper mines, which are the most dangerous in terms of environmental impact, have been closed and ooded. In many of them, acid mine waters continue to form, the concentrations of most components in which exceed the permissible values by several orders of magnitude. The formation of the chemical composition of acidic groundwater has a pronounced unsteady character: a sharp increase in the content of all components in the water after ooding and a gradual decline for many years. On Levikha copper mine (Sverdlovsk region) after lling the depression con in 2007, a site of concentrated discharge of groundwater was formed (technogenic reservoir-a failure in the zone of collapse and displacement). The concentrations of many components 10 years after the completion of ooding are higher than during the development. The analysis of regularities of non-stationary character of hydrogeochemical processes is made on the basis of the data of detailed monitoring and extended denitions of groundwater quality indicators. The main source of acidic water with increased mineralization is the collapse zone, within which the process of drainage for several decades formed technogenic sulfuric acid weathering crust enriched with secondary minerals. According to the data of numerical geoltration modeling, in the hydrodynamic balance the lateral ow coming from the surrounding areas is 60%, its value is manifested in the dilution of the solution, which is formed in the collapse zone. The time of movement of this ow in the area of collapse is 6–8 years, extremely high values of almost all indicators in the man-made reservoir are observed during this period. According to the inverse physical-chemical modeling (program code Visual MINTEQ ver. 3.0 / 3.1 was used) the composition of rocks, as a result of dissolution-deposition of which underground waters in the area of the ooded mine can be formed, is determined. The duration of the process of formation of acidic groundwater is estimated at tens of years.