title: Transport behavior of the pharmaceutical compounds carbamazepine, sulfamethoxazole, gemfibrozil, ibuprofen, and naproxen, and the lifestyle drug caffeine, in saturated laboratory columns.
abstract: Despite the large number of pharmaceutically active compounds found in natural environments little is known about their transport behavior in groundwater, which is complicated by their wide range of physical and chemical properties. The transport behavior of five widely used and often detected pharmaceutical compounds and one lifestyle drug has therefore been investigated, using a set of three column experiments. The investigated compounds were the anticonvulsant carbamazepine, the lifestyle drug caffeine, the antibiotic sulfamethoxazole, the lipid regulator gemfibrozil, and the nonsteroidal anti-inflammatories ibuprofen and naproxen. The columns were filled with three different types of sand. The substrates consisted of artificially prepared iron-coated sand, artificially prepared organic carbon sand (with 5% leaf compost), and natural aquifer sand from Long Point, Ontario (Canada). The experiments were conducted simultaneously under the same hydraulic conditions and with the same input solution of about 1μg·L-1of each compound. The transport behavior of the organic compounds differed significantly between both the different columns and the different compounds. A strong correlation was observed between the retardation factors for carbamazepine, gemfibrozil, and ibuprofen and the organic carbon content of the substrate. While the retardation increased with increasing organic carbon content, no direct relationship was observed between the organic carbon content and the removal of these compounds. In contrast, the retardation factors for sulfamethoxazole and naproxen showed no correlation with the organic carbon content but these compounds were significantly removed in the presence of organic matter. The influence of the Fe3+surfaces in the iron-coated sand was less significant than expected, with all compounds except for sulfamethoxazole having retardation factors <1.8. Caffeine was so strongly removed during transport through those substrates containing organic carbon that no reliable retardation factor could be determined.
authors.affiliation: Technische Universität Berlin, Department of Applied Geosciences, EB 10, D-10623 Berlin, Germany. Electronic address: klaus.hebig-schubert@tu-berlin.de.
authors.forename: Klaus H
authors.initials: KH
authors.lastname: Hebig
authors.affiliation: University of Waterloo, Department of Earth and Environmental Sciences, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada. Electronic address: lggroza@sciborg.uwaterloo.ca.
authors.forename: Laura G
authors.initials: LG
authors.lastname: Groza
authors.affiliation: University of Waterloo, Department of Earth and Environmental Sciences, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada.
authors.forename: Michelle J
authors.initials: MJ
authors.lastname: Sabourin
authors.affiliation: Technische Universität Berlin, Department of Applied Geosciences, EB 10, Straße des 17. Juni 135, D-10623 Berlin, Germany. Electronic address: traugott.scheytt@tu-berlin.de.
authors.forename: Traugott J
authors.initials: TJ
authors.lastname: Scheytt
authors.affiliation: University of Waterloo, Department of Earth and Environmental Sciences, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada. Electronic address: ptacek@uwaterloo.ca.
authors.forename: Carol J
authors.initials: CJ
authors.lastname: Ptacek
mesh_terms: D002110:Caffeine / Q000378:metabolism*; D002220:Carbamazepine / Q000378:metabolism; D005374:Filtration; D015248:Gemfibrozil / Q000378:metabolism; D007052:Ibuprofen / Q000378:metabolism; D009288:Naproxen / Q000378:metabolism; D009864:Ontario; D012822:Silicon Dioxide; D013420:Sulfamethoxazole / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D014874:Water Pollutants, Chemical; D002220:Carbamazepine; D002110:Caffeine; D009288:Naproxen; D012822:Silicon Dioxide; D013420:Sulfamethoxazole; D015248:Gemfibrozil; D007052:Ibuprofen
keywords: CXTFIT; Enriched organic carbon sand; Iron-coated sand; Long Point sediment; Micropollutants; Saturated column study