Modelling of the Environmental Fate and Effects of Veterinary Medicines in Soil under Field Conditions

点击翻译按钮获取中文摘要

In the 2nd phase, we simulated fate and effects of SDZ and its main metabolites under consideration of field temperature and moisture conditions and could explain a large part of the observed variability by temperature and instantaneously moisture effects. For these simulations, the established model structure and kinetic rate constants as determined from micro- and mesocosm experiments under constant conditions were used. However, implicit uncertainties of relevant processes prevent a priori predictions of SDZ fate in manured soil and resulting effects on nitrification and resistance gene selection. Both the release of SDZ and 4-OH-SDZ from the residual fraction and biotic endpoints such as abundance and activity of ammonium oxidizing archaea seems to be influenced by soil moisture conditions in a not yet well understood manner. In the 3rd phase of our Research Unit we will test the validity of the coupled fate and effect model under field conditions. The influence of variable moisture and temperature on transformation and sequestration processes of SDZ as well as on resulting effects on nitrification and resistance gene selection will be analysed based on field and greenhouse experiments. Fate and effect processes will be simulated under drying and re-wetting cycles and compared to static moisture conditions. Most sensitive processes and parameters will be identified and uncertainties of predictions quantified by Monte-Carlo analysis.