| Trichloroethylene (TCE) sorption coefficients were determined for three soil packages collected from Hill Air Force Base, UT, using a sealed batch method developed in this study. [14C]TCE was used to accurately determine sorption/desorption coefficients, and resolve sorbed [14 C]TCE into methanol extractable and methanol nonextractable fractions.; Based on observed differences between the sorption and desorption fraction, a methanol nonextractable fraction of sorbed [14C]TCE was identified in the soils studied. The concentration of this bound fraction was found to be 0.069 mg kg−1 (0.059–0.078 mg kg−1, 95% confidence intervals, n = 342), ranging from 0.14 to 14% of the spiked initial concentration.; Earthworms (Lumbricus terrestres) exposed to extractable and nonextractable soil bound [14C]TCE showed uptake from the methanol extractable fraction only. The nonextractable fraction was not bioavailable to the earthworms. Calculated biota-sediment accumulation factors for four soil types were <1.0 kgsoil kgworm−1 , indicating that while [14C]TCE was bioavailable, it was not concentrating in the earthworm tissues. The earthworm bioavailability of [14C]TCE was also observed to be directly proportional to the methanol extractable soil concentration of [14C]TCE.; The results of the sorption and desorption studies, the bioavailability study, and the nonsolvent-extractability suggest that the formation of a bound residue may be considered a mass attenuating mechanism for the purposes of contaminant transport modeling and decision-making. |
