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Upgrading of Swiss Wastewater Treatment Plants (WWTP)

Here you find a list and a map of large-scale implementations of micropollutant removal in Switzerland (German and French).

Ein Kreisdiagramm, das den Prozentsatz von cno, cno, cno, cno, c zeigt.
Current state (November 2023) of the distribution of processes to reduce micropollutants in Switzerland based on the number of WWTPs (left) and the affilated residents (right).

Criteria for WWTP expansion according to the Water Protection Ordinance (WPO) Annex 3 in Switzerland

  • Protection of aquatic ecosystems: WWTPs for > 8,000 affiliated residents (Raff) in stretches of water with a wastewater content of > 10%
  • Protection of water resources: WWTPs with > 24,000 Raff in lakecatchment areas and WWTPs > 8,000 Raff in karst areas
  • Load reduction/upstream responsibility: WWTPs with > 80,000 Raff

Frequently asked questions

Frequently asked questions regarding industry and commerce


List of selected publications

  • Bourgin, M., Beck, B., Boehler, M., Borowska, E., Fleiner, J., Salhi, E., Teichler, R., von Gunten, U., Siegrist, H. and McArdell, C.S. (2018) Evaluation of a full-scale wastewater treatment plant upgraded with ozonation and biological post-treatments: Abatement of micropollutants, formation of transformation products and oxidation by-products. Water Res. 129, 486-498.
  • Eggen R. I. L., Hollender J., Joss A., Schärer M., Stamm Ch. (2014) Reducing the Discharge of Micropollutants in the Aquatic Environment: The Benefits of Upgrading Wastewater Treatment Plants. Environ. Sci. Technol. 48, 7683-7689.
  • Göbel A., McArdell C.S., Joss A., Siegrist H., Giger W. (2007) Fate of  Sulfonamides, Macrolides and Trimethoprim in Different Wastewater Treatment Technologies. Sci. Total Environ. 372, 361-371.
  • Hollender J., Zimmermann S.G., Koepke S., Krauss M., McArdell C.S., Ort C., Singer H., Von Gunten U., Siegrist H. (2009) Elimination of organic micropollutants in a municipal wastewater treatment plant upgraded with a full-scale  post-ozonation followed by sand filtration, Environ. Sci. Technol. 43, 7862-7869, DOI 10.1021/es9014629.
  • Huber M.M., Göbel A., Joss A., Hermann N., Löffler D., McArdell C.S., Ried A., Siegrist H, Ternes T.A., von Gunten U. (2005) Oxidation of Pharmaceuticals during Ozonation of Municipal Wastewater Effluents: A Pilot Study. Environ. Sci. Technol. 39(11), 4290-4299.
  • Kovalova L., Siegrist H., von Gunten U., Eugster J., Hagenbuch M., Wittmer A., Moser R., McArdell C.S. (2013) Elimination of Micropollutants during Post-Treatment of Hospital Wastewater with Powdered Activated Carbon, Ozone, and UV. Environ. Sci. Technol. 47, 7899−7908, dx.doi.org/10.1021/es400708w.
  • Lee, Y., Gerrity, D., Lee, M., Bogeat, A.E., Salhi, E., Gamage, S., Trenholm, R.A., Wert, E.C., Snyder, S.A. and von Gunten, U. (2013) Prediction of Micropollutant Elimination during Ozonation of Municipal Wastewater Effluents: Use of Kinetic and Water Specific Information. Environmental Science & Technology 47(11), 5872-5881.
  • Schindler Wildhaber, Y., Mestankova, H., Scharer, M., Schirmer, K., Salhi, E. and von Gunten, U. (2015) Novel test procedure to evaluate the treatability of wastewater with ozone. Water Research 75, 324-335.
  • Siegrist, H., Joss, A., Boehler, M., McArdell, C.S. Ternes, T. (2018) Organic Micro-Pollutant Control. Chapter 6 in Advances in Wastewater Treatment, Editors: Giorgio Mannina, George Ekama, Hallvard Ødegaard and Gustaf Olsson, IWA Publishing, ISBN 9781780409702 eISBN 9781780409719.
  • Soltermann, F., Abegglen, C., Gotz, C. and von Gunten, U. (2016) Bromide Sources and Loads in Swiss Surface Waters and Their Relevance for Bromate Formation during Wastewater Ozonation. Environmental Science & Technology 50(18), 9825-9834.
  • von Sonntag, C. and von Gunten, U. (2012) Chemistry of ozone in water and wastewater treatment: From basic principles to applications, IWA Publishing, London.
  • Wittmer A., Heisele A., McArdell C.S., Böhler M., Longree P., Siegrist H. (2015) Decreased UV absorbance as an indicator of micropollutant removal efficiency in wastewater treated with ozone. Wat. Sci. Technol. 71.7, 980-985, doi:10.2166/wst.2015.053
  • Zimmermann, S.G., Wittenwiler, M., Hollender, J., Krauss, M., Ort, C., Siegrist, H. and von Gunten, U. (2011) Kinetic assessment and modeling of an ozonation step for full-scale municipal wastewater treatment: Micropollutant oxidation, by-product formation and disinfection. Water Research 45(2), 605-617.

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