A METHOD FOR STUDYING NONEQUILIBRIUM SORPTION DURING TRANSPORT OF PESTICIDES IN SOIL

Rate coefficients describing sorption of pesticides in soils are commonly obtained under well stirred conditions from batch equilibration studies. Batch techniques involve high solution-to-soil ratios and mechanical agitation, both of which can influence the sorption characteristics of a soil. In addition, rapid equilibration cannot be studied accurately in batch experiments. These disadvantages can, however, be overcome by studying the sorption of pesticides during leaching in saturated columns of soil. Results in this paper show how time-dependent sorption of pesticides in soil can be calculated by applying the peak maxima method from the gas-chromatographic literature to pesticide breakthrough curves of short pulse injections in soil columns.