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@PHDTHESIS{Unold:11708,
      author       = {Unold, Myriam},
      title        = {{E}xperiments and numerical studies on transport of
                      sulfadiazine in soil columns},
      volume       = {81},
      issn         = {1866-1793},
      school       = {Universität Bonn},
      type         = {Dr.},
      address      = {Jülich},
      publisher    = {Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag},
      reportid     = {PreJuSER-11708},
      isbn         = {978-3-89336-663-7},
      series       = {Schriften des Forschungszentrums Jülich : Energie $\&$
                      Umwelt / Energy $\&$ Environment},
      pages        = {XVI, 115 S.},
      year         = {2010},
      note         = {Record converted from JUWEL: 18.07.2013; Univ. Bonn, Diss.,
                      2010},
      abstract     = {Veterinary antibiotics like sulfadiazine (SDZ) are used in
                      large amounts worldwide. Excreted as parent compounds or in
                      the form of metabolites they reach agricultural soils mainly
                      via spreading of manure or sewage sludge and may be
                      transported to the groundwater. Recently, antibiotics have
                      been detected in several environmental compartments leading
                      to an increasing concern about their hazardous effects. To
                      asses the leaching potential of SDZ from soils into
                      groundwater, knowledge on its transport processes in soils
                      is necessary. Also the transport of its metabolites as well
                      as possible transformation processes have to be considered.
                      In this work transport experiments at the column scale were
                      performed. Therefore, SDZ and pig manure were used to
                      analyze the governing processes that affect the transport of
                      SDZ in disturbed and undisturbed soil columns of a loamy
                      sand and a silty loam. For this purpose the Hydrus model
                      (Šimůnek et al., 2008) has been adapted and applied to the
                      observed BTCs and resident concentrations. The occurrence of
                      transformation products in the outflow of repacked soil
                      columns of both soils was investigated in experiments with a
                      SDZ-solution. For the prediction of the
                      $^{14}$C-distribution in the repacked soil columns,
                      empirical approaches to describe irreversible sorption were
                      tested. Furthermore the influence of flow rate and
                      concentration/applied mass on SDZ transport was investigated
                      and the respective experiments were simultaneously described
                      with a common set of parameters. In transport experiments
                      with pig manure, the effect of pig manure on the transport
                      of SDZ as well as the transport behavior of the main
                      metabolites of SDZ present in pig manure, N-Ac-SDZ and
                      4-OH-SDZ, were investigated. Without considering a known
                      photo-degradation product transformation was very low in
                      both investigated soils. In soil columns where most of the
                      $^{14}$C was found near the soil surface, the prediction of
                      the $^{14}$C-concentration profiles was improved by applying
                      two empirical models other than first-order to predict
                      irreversible sorption. The application of SDZ at a higher
                      flow rate led to higher eluted masses and concentrations
                      compared to experiments conducted at a lower flow rate. The
                      simultaneous fitting process with a three site
                      attachment/detachment model revealed that although the same
                      sorption mechanisms seem to occur in all experiments, their
                      characteristic time scales were different, especially under
                      transient flow conditions. As the main difference between
                      experiments with manure and SDZ-solution an accumulation of
                      $^{14}$C in the upper soil layer was found in the
                      experiments with manure. The modeling process revealed a
                      high mobility of both SDZ and its transformation products.
                      While the transformation of N-Ac-SDZ into SDZ was fast and
                      no extended tailing of N-Ac-SDZ was observed, the transport
                      behavior of 4-OH-SDZ was similar to SDZ.},
      cin          = {ICG-4},
      ddc          = {500},
      cid          = {I:(DE-Juel1)VDB793},
      pnm          = {Terrestrische Umwelt},
      pid          = {G:(DE-Juel1)FUEK407},
      typ          = {PUB:(DE-HGF)11 / PUB:(DE-HGF)3},
      url          = {https://juser.fz-juelich.de/record/11708},
}