Environmental pollution of soil with PAHs in energy producing plants zone

Abstract

Polycyclic aromatic hydrocarbons (PAHs) are widely distributed environmental toxicants primarily formed during the incomplete combustion of organic materials (for example, coal, oil, gasoline and wood). Power energy plants are the main sources of organic contaminants including PAHs. The purpose of the present research was to study the Novocherkassk Electric Power Station (NEPS) emission effects of PAHs accumulation in soils. The regional levels, types (groups) and spatial distribution of 16 priority PAHs were investigated. The monitoring sites were located on fallow lands of the 20 km around NEPS. PAHs extraction from collected soil samples was performed using the ecologically clean express-method of subcritical water extraction. The total PAHs content gradually increased in soil of the studied territories during 2016–2017 due to an increase in contaminants emission. Accordingly 16 priority PAHs were determined in the soil samples collected from the sites located to the northwest from NEPS in direction of predominant winds. The 5-km zone situated in direction of predominant winds was highly subjected to PAHs contamination, with maximal accumulation at a distance of 1.6 km from the source. The ratio of high- and low-molecular weight PAHs content in soils of monitoring sites was taken as an index of environmental soil contamination. The high-molecular weight PAHs concentration prevailed in monitoring sites soils situated in direction of predominant winds from NEPS, while the concentration of low-molecular weight PAHs prevailed in the monitoring sites soils situated around NEPS. Soil properties also influenced PAHs accumulation. Polyarenes content in Haplic Chernozems and Haplic Chernozems (Stagnic) was higher versus Fluvisols. This study provides the understanding and model the fate of PAHs in regional technogenic landscape.