mass in the aqueous phase with the amount of soil in the

vial. The amount of each compound desorbed from the soil

(-X/m) were calculated by dividing the difference between

"the mass remained in system after draining the free water,

which was calculated from the results of adsorption

experiment" and "the mass in the aqueous phase" with the

amount of soil in the vial. Sorption coefficients were

calculated by fitting data to the Freundlich model, i.e.,

plotting log(X/m) (log(-X/m) in the cases of desorption)

versus log(C). The slope is the constant b in Equation (3-2)

and ordinate the intercept is log(KFA) or log(KFD), where

KFA (in ml/g) is the adsorption equilibrium partition

coefficient and KFD is the desorption equilibrium partition

coefficient. Recoveries were determined by the

"(calculated) mass of analyte extracted from soil" to

"(calculated) mass of un-desorbed analyte on soil" ratio.

The dilution effect caused by the solutions trapped in the

soil matrix was accounted for in the calculations of

recoveries.


4.3.2 Column Sorption Studies.


 Column sorption experiments were performed with three

12 inches long x 3 inches diameter glass columns. A

quantity of 1500 g (about 9 inches high) of sandy soil were

loaded in each column.


 Conservative tracer. The experimental setup is shown

in Figure 4-2. Soil in the columns was saturated with