Transport of Pesticides Under Aquifer Conditions

Abstract

Pesticide transport was determined in a quarternary coarse grained aquifer which was characterized by low organic carbon content. Water spiked with the pesticides atrazine, chlortoluron, isoproturon, simazine and terbuthylazine and chloride salt as conservative tracer, was injected in the aquifer. Mean residence times (MRT) of pesticides were generally 1.5 to 3 times higher than the MRT of the tracer. Sediment retention capacity calculated from experimental data yielded generally small values below 250 ng/kg sediment. Retardation characteristics were in the order of magnitude expected from literature data on organic carbon/water partition coefficients. Transport of pesticides was due to convection and dispersion whereas adsorption and degradation was low.