Influence of anthropogenic and environmental conditions on polycyclic aromatic hydrocarbon pollution originating from coal ash dumps

Abstract

Nikola Tesla B power plant (TENT-B), located on the Sava River in Obrenovac, 52 km west from the Serbian's capital, Belgrade, is the second largest coal-fired power plant in the country, consisting of two blocks of 620 MW each. Samples of fresh coal ash obtained by coal combustion in TENT-B, as well as coal ash samples from the surface and 1-m depth of active, currently filled, and passive, previously filled and not currently used, cassettes, were taken from the coal ash dump. Ultrasonic extracts of the samples were analyzed using gas chromatography with mass selective detection (GC/MSD) in order to identify and quantify 16 priority polycyclic aromatic hydrocarbons (PAHs). Two PAH extraction mechanisms during coal ash dumping and storage processes are discussed and significant differences between them were established. PAH concentrations in the ash samples were compared statistically. Correlations between samples and sampling points were established, and leaching potential of samples was examined. Concentrations of PAHs can be reduced in coal ash sediments by environmental influences only after long time periods, and PAHs with two six-membered rings pose danger to underground waters, while PAHs with three rings pose danger to soil sediments.