Sorption reactions of 1,4-dichlorobenzene in low organic carbon soils

Abstract

The rate and extent of sorption of 1,4-dichlorobenzene (1,4-DCB) was studied using column and batch experiments. Column experiments with a soil with fraction organic carbon (foc) = 0.00086 yielded a soil/water partition coefficient (K r ) of 0.41; mass balance on the sorption and desorption limbs of the breakthrough curves gave similar Kp's, indicating sorption was readily reversible. A computer program that fits column effluent data to analytical solutions of the advection-dispersion equation under different models of sorption behaviour gave Kp = 0.46, assuming equilibrium sorption. The breakthrough curves for 1,4-DCB showed slight tailing when plotted against the fitted data, indicating some slow sorption. The time scale for sorption/desorption estimated by this program was up to 10-100 times larger than (physical) transport times in the column, but was of the same order as transport times in the field.