Assessment of soil changes causing contamination with crude oil and mineralized liquids in the Middle Ob region (Western Siberia)

Abstract

The influence of highly mineralized waters and crude oil on the properties of podzolic and alluvial soils in Western Siberia is analyzed. Soils contaminated with mineralized waters during oil production accumulate easily soluble salts, as shown by the amount of dense residue within the contamination halo (0.30–1.68%), including high content of toxic salts (toxic chloridesulfate and sulfate anions and toxic cation sodium), which create an unfavorable environment for the growth and development of higher plants. Salt accumulation and the chemistry of soil salinization in oil production areas depends both on the type of pollution (crude oil, mineralized waters) and on soil-ecological conditions (landscape position, hydrological regime, genetic type of soils and their sorption properties, regime of salt supply). The discharge of mineralized waters during spillages in waterlogged taiga landscapes of Western Siberia leads to technogenic halogenesis (salinization) in areas where this process could never have occurred naturally. Soil salinization, which occurs in a humid climate, can be considered a superimposed soil-forming process, which forms an additional risk of the development of an accompanying solonchak process in soils. The changes revealed allow the ecological state of soils to be assessed. Proposals for the reclamation of oil-salt contaminated soils can be put forward, based on basic parameters of technogenically saline soils (chemistry, degree of salinization, and stock of toxic salts).

Keywords

• oil and salt pollution
• easily soluble salts
• technogenic halogenesis
• salinization chemistry
• soil salt profile
• reclamation methods
• phytomelioration