Fate of pharmaceuticals in rivers: deriving a benchmark dataset at favorable attenuation conditions

摘要: Abstract Pharmaceutical residues are commonly detected organic micropollutants in the aquatic environment. Their actual fate rivers is still incompletely understood as their elimination highly substance specific and studies often report contradictory results. To elucidate ceiling of attenuation rates pharmaceuticals we carried out a study at river with favorable conditions for micropollutants. Experiments were small stream Germany. Composite samples taken both ends 12.5 km long stretch located downstream sewage treatment plant analyzed 10 pharmaceuticals. Moreover, pore water situ photolysis experiments several sites within performed to assess importance these individual mechanisms. concentration surface first sampling site ranged from 3.5 ng L−1 propranolol 1400 ng L−1 diclofenac. In comparison carbamazepine which was used persistent tracer, all other attenuated along stretch. higher sunny, dry weather period (period I) compared elevated discharge after heavy rainfall II). Overall, measured 25% sulfamethoxazole II) 70% I). Photolysis only relevant process diclofenac potentially also sotalol; compounds phototransformation half-life times some hours determined unshaded parts river. Biotransformation sediments an important since concentrations decreased relative depth. For chiral betablocker metoprolol this biotransformation confirmed by decrease enantiomer fractionation 0.49 A 0.43 B