AN INVESTIGATION OF COAL DUST TRANSPORT NEAR THE LAFAYETTE RIVER, NORFOLK, VA

To investigate the transport of coal dust from Norfolk Southern’s Lamberts Point coal terminal in Norfolk, VA, this study examined the concentrations of polycyclic aromatic hydrocarbons (PAHs) and aliphatic n-alkanes in surface sediments (1-2 cm) among several sites in the Elizabeth River near the coal terminal as well as particles collected by wet and dry deposition at one site on Old Dominion University’s campus. All samples were collected between June 15 and July 20. The samples were extracted using a MARS microwave accelerated extraction system and split; PAH fractions were analyzed by Gas Chromatography - Mass Spectrometry (GC-MS) and n-alkane fractions were isolated by solid phase extraction and then analyzed by GC-MS/GC-FID (Flame Ionization Detection). A total of 54 PAHs (27 parent, 27 alkyl-substituted) and 20 n-alkanes (C₁₃ – C₃₃) were identified. Surface sediments yielded total concentrations between 2434 ng/g dry weight and 68543 ng/g dry weight with concentrations of individual PAHs ranging from 0.09 ng/g dry weight (naphthalene) to 4072 ng/g dry weight (dimethylnaphthalene). Total n-alkane concentrations ranged from 3 µg/g dry weight to 46 µg/g dry weight with concentrations of individual n-alkanes ranging from 51 μg/g dry weight (C₁₆) to 19406 μg/g dry weight (C₂₉). Wet deposition samples yielded abundances of individual PAHs ranging from 0.01 ng (perylene) to 620 ng (trimethylnaphthalene) and of n-alkanes from 211 ng (C₂₄) to 20342 ng (C₂₉). These values were compared to two coal samples collected from the terminal, which yielded PAH concentrations from 0.67 ng/g dry weight (indo[1,2,3-cd]pyrene) to 4072 ng/g dry weight (dimethylnaphthalene) and n-alkane concentrations from 196 μg/g dry weight (C₃₁) to 3155 μg/g dry weight (C₁₅). All sediment and deposition samples showed high levels of combustion byproducts, indicating that organic contamination is being transported across campus. Specific sources must be refined in order to distinguish between energy sources and local combustion byproducts.