 |
| Titel |
Ad-/desorption behavior of Sulfadiazine on soil and soil components |
| VerfasserIn |
N. Meng, H. Lewandowski, R. Kasteel, H.-D. Narres, E. Klumpp, H. Vereecken |
| Konferenz |
EGU General Assembly 2009
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250023710
|
|
|
|
|
|
| Zusammenfassung |
| Sulfadiazine [4-amino-N-(2-pyrimidinyl)benzene sulfonamide, SDZ] belongs to the widely
used antibacterial veterinary pharmaceuticals which reach the environment by the application
of manure. Therefore the adsorption and desorption behavior of 14C labeled sulfadiazine was
investigated with different inorganic soil components including Al2O3, goethite, illite and
compared with air-dried topsoil. The batch sorption experiments with Al2O3and soil were
performed in natural pH-values (8.2 and 7.5, negatively charged SDZ). Experiments with
illite and goethite were done with pH-values of 4.2 and 6.8 (natural pH of illite
and goethite, neutral and partly negatively charged SDZ) and also done in buffer
solution about pH 8 for comparing the adsorption on all adsorbents in same pH
range.
The adsorption isotherms on all sorbents are strongly nonlinear and can be fitted well by
the Freundlich equation. From the initial slope of the isotherm the partition coefficient Kd
could be determined. The adsorption of SDZ on illite at pH 4.2 and on goethite at pH 6.8 has
higher Kd-values than at pH 8, which demonstrates that the negative charge of SDZ obstructs
the adsorption.
The desorption isotherms show hysteresis effects for all adsorbents. The strong hysteresis
was found for goethite and soil indicates strongly physical or chemical binding. On the other
hand, the low hysteresis effect for Al2O3 and illite indicates the weak binding of the adsorbed
SDZ. The properties of the inorganic matrix and especially the charges of the inorganic
compounds in relation to the charge of SDZ are important parameters for the sorption
process. The data could be described by modeling with different sorption rates and sites. |
|
|
|
|
|
|