Leaching of 2,4-D from a soil in the presence of beta-cyclodextrin: laboratory columns experiments

This study reports on the effect of the presence of beta -cyclodextrin (bet a -CD) on the adsorption and mobility of the pesticide 2,4-dichlorophenoxya cetic acid (2,4-D) through soil columns. The previous application of beta - CD to the soil produced a retarded leaching of 2,4-D through the soil colum n, due probably to herbicide adsorption on the soil through beta -CD adsorb ed. However, the application of beta -CD solution to the soil column where 2,4-D had been previously adsorbed, led to the complete desorption of the h erbicide, due to the formation of water-soluble 1:1 inclusion complexes bet ween 2,4-D and beta -CD. beta -CD can be viewed as a microscopic organic-ph ase extractant. It can be an advantage to remove from soil pesticides which are able to form inclusion complexes with cyclodextrins, making them possi ble candidates for use in in situ remediation efforts. (C) 2001 Elsevier Sc ience Ltd. All rights reserved.