Estimating release of polycyclic aromatic hydrocarbons from coal tar at manufactured-gas plant sites

Technical Report · Sat Aug 01 04:00:00 EDT 1992

OSTI ID:7152397

Loehr, R C ^[1]; Rao, P S.C.; Lee, L S; Okuda, I ^[2]

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1. Texas Univ., Austin, TX (United States). Dept. of Civil Engineering
2. Florida Univ., Gainesville, FL (United States). Dept. of Soil Science

One component of the EPRI's research on Envirorunental Behavior of Organic Substances (EBOS) consists of developing information and models to predict releases of monocyclic and polycyclic aromatic hydrocarbons (MAHs and PAHs) to groundwater from coal tars and contaminated soils at MGP sites. The results of this report focus primarily on release of PAHs from coal tars. There are at least two approaches to predicting the release of organic chemicals from coal tar to water. The simplest method to estimate aqueous concentrations is to assume that water solubility of a PAH compound released from the tar can be defined by equilibrium precipitation-dissolution reactions. Application of Raoult's law is another method to predict aqueous concentrations, which requires the assumption of ideal'' behavior for partitioning of PAHs between the tar and water phases. To evaluate the applicability of these two methods for predicting PAH releases, laboratory experiments were conducted with eight coal tar samples from former MGP sites across the country. Migration of chemicals in the environment and resulting contaminant plumes in groundwater are determined by leachate concentrations of the chemicals. The use of equilibrium precipitation-dissolution reactions will usually result in an overestimation of PAH concentrations in the leachate from a coal tar source, and thus the resulting PAH concentrations in groundwater. Raoult's law appears to be a more accurate approach to predicting the release of several PAHs from coal tars. Furthermore, if nonequilibrium conditions prevail, aqueous-phase PAH concentrations will be even lower than those predicted using Raoult's law.

• Research Organization: Electric Power Research Inst., Palo Alto, CA (United States); Texas Univ., Austin, TX (United States). Dept. of Civil Engineering; Florida Univ., Gainesville, FL (United States). Dept. of Soil Science
• Sponsoring Organization: EPRI; Electric Power Research Inst., Palo Alto, CA (United States)
• OSTI ID: 7152397
• Report Number(s): EPRI-TR-101060
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010404* -- Coal
Lignite
& Peat-- Gasification
010900 -- Coal
Lignite
& Peat-- Environmental Aspects
AROMATICS
COAL GASIFICATION PLANTS
COAL TAR
DENSITY
DISSOLUTION
EPRI
GROUND WATER
HYDROCARBONS
HYDROGEN COMPOUNDS
INDUSTRIAL PLANTS
LEACHING
MANAGEMENT
MIGRATION
ORGANIC COMPOUNDS
OTHER ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
POLYCYCLIC AROMATIC HYDROCARBONS
SEPARATION PROCESSES
TAR
VISCOSITY
WASTE DISPOSAL
WASTE MANAGEMENT
WATER