Geochemical features of migration flows in the impact zone of mining technogenesis (Mednogorsk)

Abstract

The relevance of the research is caused by large-scale pollution of natural ponds and rivers which occurs at mine drainage, containing elevated concentration of metals, sulphates and other components, run into uncontaminated waters. Assessment of the degree of natural and technogenic waters balance to hydrogenic minerals is currently an urgent problem. Its solution allows describing the nature of the geochemical specifics of technogenic water, and the mechanisms of their formation, identifying the sources of chemical elements and processes of secondary mineral formation, forms of migration of toxic elements in the technogenic streams and their impact on the environment. The aim of the study is finding-out the regularities of secondary mineral formation in anthropogenic streams as major factor of removal of metals from solutions. The methods used in the study. Physical and chemical modeling of chemical species in solution was calculated using WATEQ4f code. At the same time the authors have calculated saturation indexes, indicating a potential undersaturation or supersaturation of solution with respect to various mineral phases. The results. The paper introduces the results of physico-chemical modeling of Mednogorsk geotechnical system with application of the WATEQ4f package. The authors calculated the chemical species of elements and saturation indexes with respect to a number of mineral phases. Various hydroxides and different types of jarosite, which are unstable in the mixing zone with Zhiriklya River and are able to dissolve, can be formed in water samples under study. These findings indicate the transition of goethite to ferrihydrite in the mixing zones of Green and Blue mine drainages and in Zhiriklya and Blyava rivers