Author(s)

Estelle Larsson, Ayman Rabayah, Jan Åke Jönsson

Lund University, Lund, Sweden.
Triumpharma LLC, Amman, Jordan.

In this study, the fate of four common anti-inflammatory drugs (ketoprofen, naproxen, diclofenac and ibuprofen) within a wastewater treatment plant was investigated. A previously developed direct hollow fiber liquid phase microextraction method was applied to water as well as sludge samples collected from the primary, secondary and tertiary treatment respectively and the final analysis was performed by liquid chromatography quadropole time of flight tandem mass spectrometry. Enrichment factors ranged from 1400 to 3900 times depending on analyte and matrix. Method detection limits ranged from 0.3 to 14 ng/L for the different analytes and matrices. The overall sludge removal was 9%, 3%, 13% and 1% for ketoprofen, naproxen, diclofenac and ibuprofen respectively, thus indicating that of the studied compounds, ketoprofen and diclofenac to the largest extent partition into the sludge. For both substances, the largest fraction was found in secondary sludge (60% and 80% respectively of the total amount detected in the sludge). For naproxen and ibuprofen, the largest fraction were on the other hand detected in primary and tertiary sludge respectively, indicating that the affinity to the different sludge types might vary among the four drugs. The overall low sludge removal confirms existing theories that partitioning into sludge is only a minor removal mechanism for the investigated compounds. Nevertheless, naproxen and ibuprofen are still efficiently removed from the water during treatment (100% and 97 % total removal respectively) suggesting that these compounds are highly susceptible to biodegradation while ketoprofen and diclofenac (66% and 67% total removal respectively) appear more persistent.

Pharmaceuticals; Sewage Sludge; HF-LPME; NSAID; Extraction; WWTP; Analysis

E. Larsson, A. Rabayah and J. Jönsson, "Sludge Removal of Nonsteroidal Anti-Inflammatory Drugs during Wastewater Treatment Studied by Direct Hollow Fiber Liquid Phase Microextraction," Journal of Environmental Protection, Vol. 4 No. 9, 2013, pp. 946-955. doi: 10.4236/jep.2013.49109.