City refuse compost and sodium dodecyl sulphate as modifiers of diazinon leaching in soil

Abstract The effect of a city refuse compost (CRC) and of an anionic surfactant (sodium dodecyl sulphate (SDS) on the leaching of diazinon (0,0-diethyl 0-2-isopropyl-6-methylpyrimidin-4-yl-phosphorothioate) in the soil was studied using packed soil columns. Breakthrough curves showed the existence of various regimes of pesticide adsorption related to the pesticide and organic material nature and the soil properties. Leaching rate and mass transfer of diazinon decrease following the addition of CRC to the soil and increase after the addition of SDS. The degree of increase or decrease was found to depend strongly on the amendment dose added, especially in the case of SDS. The results afford basic data on which to base the possible use of the organic amendments studied in physicochemical methods designed to prevent the pollution of water by hydrophobic pesticides (immobilization) or to restore soils contaminated by these compounds (leaching).