Pt. Imhoff et al., COMPLETE DISSOLUTION OF TRICHLOROETHYLENE IN SATURATED POROUS-MEDIA, Environmental science & technology, 32(16), 1998, pp. 2417-2424
Porous media containing trichloroethylene (TCE) trapped at residual sa
turation in otherwise water-saturated porous media were flushed with w
ater to assess the dissolution rate of TCE as TCE volumetric fractions
approached zero. Careful attention to column design and experimental
methods limited the effect of column materials on effluent concentrati
ons. Effluent concentration measurements during TCE dissolution are pr
esented for a glass bead porous medium, a mixed sand, and a treated so
il. Effluent concentrations were measured as they decreased below 5 mu
g/L, the maxim um allowinant level, in the gla ss bead and mixed sand
media. Efflable contamuent concentrations from columns packed with tr
eated soil were measured down to 20 mu g/L. Solvent extraction of the
treated soil after the dissolution experiments revealed that extremely
small quantities of TCE were retained in this medium. Results from pa
rallel experiments on columns exposed to only aqueous TCE suggest that
TCE remaining in the treated soil columns was sorbed to the porous me
dium. Existing power-law models were capable of describing TCE dissolu
tion in these media, if the exponent an the TCE Volume fraction was mo
dified appropriately.