Abstract

Pharmaceutical residues are polluting the surface water environments worldwide. Sewage and wastewater treatment, therefore, needs to be improved in order to remove pharmaceutical residues from the effluent. One such treatment improvement is effluent ozonation. Even though ozonation has proven to be very efficient in reducing pharmaceutical parent compound concentrations in wastewater effluents, much remains unclear regarding potentially toxic ozonation by-product (OBP) formation. In this study, we sought to elucidate the aquatic toxicity of ozonated pharmaceuticals in zebrafish (Danio rerio) embryos in a static 144 h post fertilization (hpf) fish embryotoxicity (ZFET) assay. Three pharmaceuticals commonly detected in wastewater effluents, i.e. carbamazepine, diclofenac, and oxazepam, were selected for testing. Toxicity was assessed before and after 1 min ozonation (0.053 mg L-1 peak O-3 concentration) and 10 min ozonation (0.147 mg L-1 peak O-3 concentration). Chemical analysis showed that carbamazepine and diclofenac were largely removed by ozone (90 +/- 11% and 97 +/- 3.8%), whereas oxazepam was removed to a lesser extent (19 +/- 5.7%). The ZFET assay revealed diverging toxicities. Diclofenac embryotoxicity decreased with increasing ozonation. Oxazepam did not cause embryotoxicity in the ZFET assay either pre- or post ozonation, but larvae swimming activity was affected at 144 hpf. Carbamazepine embryotoxicity, on the other hand, increased with increasing ozonation. Chemical analysis showed the formation of two OBPs (carbamazepine-10,11-epoxide and 10,11-dihydrocarbamazepine), possibly explaining the increased embryotoxicity. The results of this study highlight the importance of new chemical and toxicological knowledge regarding the formation of OBPs in post-ozonated effluents. (C) 2019 The Authors. Published by Elsevier Ltd.

Keywords

Ozonation; Ozonation by-products; OBP; Pharmaceuticals; Ozone removal efficiency; Developmental toxicity

Published in

Chemosphere
2019, Volume: 225, pages: 191-199

SLU Authors

• Pohl, Johannes

  • Department of Animal Biosciences, Swedish University of Agricultural Sciences
    

• Ahrens, Lutz

  • Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences
    

• Carlsson, Gunnar

  • Department of Animal Biosciences, Swedish University of Agricultural Sciences
    

• Golovko, Oksana

  • Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences
    

• Norrgren, Leif

  • Department of Animal Biosciences, Swedish University of Agricultural Sciences
    

• Weiss, Jana

  • Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences
    

• Örn, Stefan

  • Department of Animal Biosciences, Swedish University of Agricultural Sciences
    

Sustainable Development Goals

Ensure availability and sustainable management of water and sanitation for all


UKÄ Subject classification

Geochemistry
Environmental Sciences


Publication identifier

DOI: https://doi.org/10.1016/j.chemosphere.2019.03.034

Permanent link to this page (URI)

https://res.slu.se/id/publ/99527