title: Seasonal variation in the occurrence of pharmaceuticals in effluents from a sewage treatment plant and in the recipient water.
abstract: The occurrence of five pharmaceuticals (ibuprofen, naproxen, ketoprofen, diclofenac, and bezafibrate) in the influent and effluent water of a sewage treatment plant (STP) in the recipient river water and in a drinking water treatment plant (DWTP) located downstream from the STP was followed during three seasons: winter, spring, and summer. In the STP, the elimination of the pharmaceuticals decreased significantly (an average of 25% compared to spring and summer) in wintertime leading to increased concentrations of pharmaceuticals in the effluent water. The total concentration of all the studied pharmaceuticals in the effluent water was 3-5 times higher in wintertime (about 2500 ng L(-1)) than during the other seasons (about 500-900 ng L(-1)). Accordingly, the highest concentrations (up to 129 ng L(-1)) in the recipient river were measured in the wintertime. Pharmaceuticals were carried longer distances downstream from the STP when the river was covered by ice and snow. During a drastic increase in water flow rate (i.e., during snowmelting), a fast transportation of the pharmaceuticals was observed. The DWTP located downstream from the STP produced water that contained about 8 ng L(-1) of ibuprofen and ketoprofen in the winter sample, whereas in spring and summer the studied pharmaceuticals could not be detected in the drinking water. The results show that cold seasons in boreal areas can severely increase the environmental risk of pharmaceuticals and the risk for contamination of drinking water.
authors.affiliation: Abo Akademi University, Department of Organic Chemistry, Biskopsgatan 8, FIN-20500 Abo, Finland.
authors.forename: Niina M
authors.initials: NM
authors.lastname: Vieno
authors.forename: Tuula
authors.initials: T
authors.lastname: Tuhkanen
authors.forename: Leif
authors.initials: L
authors.lastname: Kronberg
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004364:Pharmaceutical Preparations / Q000032:analysis*; D012621:Seasons; D012722:Sewage; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D004364:Pharmaceutical Preparations; D012722:Sewage; D014874:Water Pollutants, Chemical