The diffusion of chlorinated hydrocarbons in particles of activated carbon

Computed values of the effective diffusion coefficient, D-e, ranging from 4,93 x 10(-10) to 5.96 x 10(-10) m(2)/S were obtained from kinetic data for the adsorption of 1,2-dichloropropane from a mixture with air on to activated carbon particles at concentrations within the range 14.94-31.51 g/m(3). Such kinetic adsorption data were obtained over the temperature range 24.1-25.8degreesC. Using the dependence D-e = f(C-A0), it was possible to compare the calculated values of D-e for 1,2-dichloropropane with the experimental data for 1,2-dichloroethane obtained from adsorption measurements. The values of the effective diffusion coefficients for 1,2-dichloropropane as calculated from its desorption by pure air were within the range 1.67 x 10(-10)-2.01 x 10(-10) m(2)/s at temperatures of 24.0-24.2degreesC. The considerable difference between the values of the effective diffusion coefficient for 1,2-dichloropropane in activated carbon particles as estimated from adsorption and desorption data may be associated with the non-linear course of the adsorption isotherm.