es980638z_si_001.pdf (136.93 kB)
Studies on the Dissolution of Polycyclic Aromatic Hydrocarbons from Contaminated Materials Using a Novel Dialysis Tubing Experimental Method
journal contribution
posted on 1999-06-15, 00:00 authored by Paula J. Woolgar, Kevin C. JonesAssessment of risk and remediation strategies at
contaminated sites requires that both the amounts of
contaminants present and their potential for release from
materials and soils be evaluated. The release, or
dissolution, of polycyclic aromatic hydrocarbons (PAHs)
from contaminated materials to water was therefore
investigated. To facilitate investigations of PAH dissolution
from physically disparate materials such as solid coal
tars, creosote, oil, and spent oxide, an experimental method
for measuring dissolved PAHs was developed employing
dialysis tubing in a batch-type system. This was validated
and compared to aqueous-phase PAH concentrations
measured using more traditional techniques and also predicted
using Raoult's law. The experimental procedure was
successfully used to determine ‘near equilibrium' aqueous
concentrations of PAHs, but it could only be used to
determine relative rates of approach to equilibrium as the
dialysis tubing effected the rate constants. It was found
that the contaminant materials influenced dissolution, in
particular the close to equilibrium concentrations. For
materials chemically similar to PAHs, such as nonaqueous-phase liquids (NAPLs), the concentrations could be
predicted using Raoult's law. For materials that were
chemically dissimilar to PAHs, such as spent oxide, release
was more thermodynamically favorable than for NAPLs.