Role of weathered coal tar pitch in the partitioning of polycyclic aromatic hydrocarbons in manufactured gas plant site sediments

Journal Article · Fri Sep 15 04:00:00 EDT 2006 · Environmental Science and Technology

DOI:https://doi.org/10.1021/es0607032· OSTI ID:20813180

Khalil, Muhammad F; Ghosh, Upal; Kreitinger, Joseph P ^[1]

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1. University of Maryland Baltimore County, Baltimore, MD (United States). Department of Civil and Environmental Engineering

Polycyclic aromatic hydrocarbons (PAHs) in manufactured gas plant (MGP) site sediments are often associated with carbonaceous particles that reduce contaminant bioavailability. Although black carbon inclusive partitioning models have been proposed to describe elevated PAH partitioning behavior, questions remain on the true loading and association of PAHs in different particle types in industrially impacted sediments. In the studied MGP sediments, the light density organic particles (coal, coke, wood, and coal tar pitch) comprised 10-20% of the total mass and 70-95% of the PAHs. The remainder of the PAHs in sediment was associated with the heavy density particles (i.e., sand, silt, and clays). Among the different particle types, coal tar pitch (quantified by a quinoline extraction method) contributed the most to the bulk sediment PAH concentration. Aqueous partition coefficients for PAHs measured using a weathered pitch sample from the field were generally an order of magnitude higher than reported for natural organic matter partitioning, and match well with theoretical predictions based on a coal tar-water partitioning model. A pitch-partitioning inclusive model is proposed that gives better estimates of the measured site-specific PAH aqueous equilibrium values than standard estimation based on natural organic matter partitioning only. Thus, for MGP impacted sediments containing weathered pitch particles, the partitioning behavior may be dominated by the sorption characteristics of pitch and not by natural organic matter or black carbon. 25 refs., 5 figs., 1 tab.

• OSTI ID: 20813180
• Journal Information: Environmental Science and Technology, Journal Name: Environmental Science and Technology Journal Issue: 18 Vol. 40; ISSN ESTHAG; ISSN 0013-936X
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
COAL
COAL GASIFICATION PLANTS
COAL TAR
DENSITY
PARTICLES
PARTITION
PITCHES
POLYCYCLIC AROMATIC HYDROCARBONS
SAND
SEDIMENTS
TOWN GAS
WOOD