DESORPTIVE BEHAVIOR OF TRICHLOROETHYLENE IN CONTAMINATED SOIL

An investigation of the desorptive behavior of trichloroethylene (TCE) in a long-contaminated soil (silty clay) was conducted. Batch desorption of TCE reached steady state within 24 h. The temporal dependence of TCE desorption was reinforced in reequilibration studies, where a persistent fraction of TCE desorbed very slowly. The effect of pH was negligible and TCE desorption decreased with increases in ionic strength beyond 0.1 M. Batch adsorption of TCE reached an apparent steady state in 3 days. The soil adsorption partition coefficient for TCE was estimated as 11.7 mL/g. Adsorption and desorption were not reversible over short equilibration times (on the order of days). With a short soil column, continuous TCE desorption showed an initial fast rate and a subsequent slower rate, revealing the high persistence of ppb levels of TCE in long-contaminated soil.