Polycyclic aromatic hydrocarbons in bottom sediments of an inner-city lake in the zone of discharge of surface runoff

Abstract

The study determined the content of polycyclic aromatic hydrocarbons (PAHs) in the bottom sediments of an inner-city Sredny Kaban Lake (Kazan, Russia) in the places of the organized release of untreated surface stormwater runoff within the catchment of the city. The content of 15 PAHs included in the priority list of PAHs for environmental research in the Russian Federation and in other countries was experimentally studied. The average content of the total PAHs studied (333.4 μg/kg) in the bottom sediments of the lake indicates a low degree of pollution. The analysis of the ratio of the content of individual PAHs reveals the main sources of their entry: fuel combustion (vehicles) and oil pollution of the surface water. Benzo(g,h,i)perylene and Benz(a)pyrene represent the largest contribution to the hazard coefficient of all studied PAHs for bottom sediments of the studied water body. Bottom sediments are composed mainly of particles with a size of 1–100 μm; the contribution of particles with a size of 0.1–1 μm was estimated to be up to 1%.