Effects of redox conditions and geology on pesticide degradation

  • Albrechtsen, Hans-Jørgen (Project Manager)
  • Mosbæk, Hans (Project Participant)
  • Refstrup, Mona (Project Participant)
  • Pedersen, Philip Grinder (Project Participant)

Project Details

Description

Degradation of pesticides in aquifers will be investigated by aseptically collecting sediment and water samples from various redox environments (e.g., aerobic, denitrifying, sulfate- and iron-reducing and methanogenic). Samples will be obtained from different aquifers representing typical geological settings in Denmark. Sediment and groundwater amended with low concentrations of pesticides (typically below 10 mg/l) will be incubated in the laboratory at field redox conditions and temperatures. The removal of pesticides and the accumulation of metabolites in the sediment-groundwater will be analyzed using HPLC and GC-MS. Complete mineralization will be assessed by addition of 14C-labelled pesticides and measurement of 14CO2 evolution. The degradation observed will be compared to the biomass and activity of dominant bacterial groups (i.e., aerobic, denitrifying, Fe(III)/Mn(IV)-reducing, sulfate-reducing and methanogenic) as well as to geochemical conditions in the aquifer. Finally, the degradation of pesticides in the field will be investigated at selected sites using in situ microcosms.
These field investigations will facilitate the comparison and transfer of laboratory results to field conditions.
StatusFinished
Effective start/end date01/10/199631/12/2000