Fate of MCPP and atrazine in an anaerobic landfill leachate plume (Grindsted, Denmark)

The fate of the two pesticides MCPP (mecoprop) and atrazine was investigated in an anaerobic aquifer downgradient from the Grindsted Landfill, Denmark, by means of a field injection experiment, in situ microcosms and laboratory batch experiments. The redox conditions in the experiments were dominated by iron reduction, but also methanogenesis and sulfate reduction occurred closest to the landfill. No degradation nor sorption was observed for the two pesticides in any of the biologically active experiments. In microbially inhibited laboratory experiments, supplied with sodium azide as a sterilizing agent, a chemical degradation of atrazine occurred.