Coal-related sources of organic contamination in sediments and water from the Bierawka River (Poland)

River sediments mixed with coaly material occur all along the length of the Bierawka River (Poland). To identify the origin of the coal in the sediment, the coaly material was investigated by reflected light microscopy and Rock Eval Pyrolysis, and solvent extracts by gas chromatography-mass spectrometry (GC-MS). Organic compounds dissolved in water were separated by solid phase extraction (SPE) and analyzed by GC-MS. The results point to a kerogen III source. Petrographic analyses confirm abundant coal-, charred- and coked particles in the sediments. Vitrinite reflectance varied between 0.66-0.80 Rr% without any large spatial variation. The coaly particles have different sources. Generally, the primary origin of coal particles is from coal processing and the dumping the ash with unburned coal particles from a glass factory near the river source. Later, this material was redeposited along the entire river course. In addition, hard coal processing (crushing-washing) features are visible in larger coal pieces. A second source of coaly organic matter is a coal waste dump at Szczygłowice where intensive erosion of steep slopes has delivered copious amounts of organic matter into the river. The mixing of this organic matter with that from the glass factory is clearly identified on a ternary diagram. PAH distributions also show differences between sections. The coal particle input from the waste dump increased the relative content of naphthalene relative content downstream. As in the coal waste, 4-5 ring PAHs predominate in the sediments. The pyrogenic origin of PAHs and aromatic compounds such as methylbiphenyls and dibenzofurane in the sediment is indicated by diagnostic PAH ratios; burned particles were identified petrographically. The river water contains only 2-3 ring PAHs, possibly of industrial origin or leached from coal particles in the river sediments.