The article examines the mechanisms of metal migration and immobilization in the soils of the Western Siberian Subarctic resulting from contamination associated with hydrocarbon development. The research is based on the analysis of 106 soil and soil solution samples for metal content (Na, Ca, K, Fe, Mn, Cd, Cr, Zn, Sr, Cu, Ni, Ba, Pb, Co, V) and petroleum hydrocarbons in the soil, collected at oil fields and background sites in the Nadym-Pur-Taz interfluve. Statistical modeling based on geochemical data was conducted using multivariate statistical methods. The first stage involved data factorization and factor interpretation, identifying drilling cuttings, formation waters, and motor vehicles as primary sources of pollution. Discriminant analysis enabled the grouping of samples based on the nature of the impact. Multivariate analysis of variance made it possible to identify the key factors governing metal mobility potential in soils. These factors were subsequently used as predictors in multiple regression analysis (MRA). MRA revealed the primary mechanisms of metal mobilization into solution: competitive sorption (Mn, Sr, Co, Pb, Cr, Ca, Ba, Zn), solution ionic strength (Na, Mn, Zn), soil alkalinization (Cr, V), and hydrophobization by petroleum hydrocarbons (Sr, Zn). It has been established that immobilization is most effective during ion-exchange sorption processes involving amorphous oxyhydroxides of Fe (Na, Ca, Mn, Sr, Zn) and Mn (Ba, Co, Cr, Pb), as well as organic matter of the humic series (Sr, Ba). A detailed characterization of metal behavior under contamination conditions is provided. It has been shown that the lateral migration of metals under the studied conditions ranges from 150 to 200 m. The reliability of multiple regression models was assessed, and internal validation was performed using experimental data. Based on an analysis of metal mobilization and immobilization mechanisms, recommendations are provided for reducing the migration potential of pollutants.

Nature-like technologies are being introduced into many human activities including mining wastewater treatment. This work is based on long-term studies of the Sibay copper-zinc-pyrite deposit development. It is dedicated to assessment of geochemical barriers effectiveness in Cu, Zn, Cd removal from water of the Karagayly River (receiving quarry and dump drainage water). The research is based on the elements’ content and forms in water and bottom sediments, pH values etc. Four types of hydrogeochemical environment (formed due to changes in the water use over the past 20 years) were distinguished using discriminant analysis. The mechanisms of barriers formation and destruction were described. Statistical modeling of the metals’ precipitation was performed by multivariate regression analysis. Cu is adsorbed by recently formed Fe hydroxides, and, to a lesser extent, precipitates with sulfates as water pH increases. Antagonism to Mn hydroxides has been demonstrated, due to different physicochemical conditions for their precipitation. Zn enters solid phase mainly with sulfates, this element also forms its own mineral phases. The second mechanism is adsorption by recently formed Mn hydroxides, which corresponds to the idea of similar conditions for the precipitation of metal hydroxides. Cd behavior reflects conditions intermediate between these of Cu and Zn. Contribution of both mechanisms (related to Fe hydroxides and aqueous sulfates) is equal. Antagonism to Mn is absent. According to the assessment results using of nature-like technologies in situ in watercourses, canals and other water drainage systems is promising. Developed statistical models can be used for needs of experimental studies and artificial geochemical barriers engineering.

Complex of geochemical studies in developing of Sibai chalcopyrite deposits are conducted. The peculiarities of the chemical composition of natural waters, the specificity of technogenic migration of ore elements in river sediments and soils, as well as the involvement of heavy metals into the biogeochemical cycle are established. The extent of transformation of natural geochemical processes in technogenesis is revealed. Approximate dimensions of man-made streams and scattering halos of ore metals are determined. The recommendations at reducing anthropogenic migration of elements are aimed.