Desorption kinetics of selected polynuclear aromatic hydrocarbons from anthropogenically and artificially contaminated soils

Experiments were conducted to determine desorption rates of selected PAHs from anthropogenically and artificially contaminated soils. A gas purge apparatus was used to initiate desorption of the sorbed compounds to the aqueous phase and to transfer them to the gas phase. placed in the gas stream were sampled to determine desorption as a function of time. Desorption was less than 15% over a period of one month for anthropogenically contaminated soils, and ranged from 100 to 79 % in two weeks for soils contaminated artificially and incubated for short time periods. It was concluded that desorption rate was strongly related to contamination age and to the extent of contamination. Ideal reversibility was not apparent which supported the theory of hysteresis.