Dübendorf, Switzerland
#00286
Implements
#00386 Add validated advanced treatment to high-risk wastewater systems
Implementer
ARA Neugut wastewater treatment plant and Swiss research partners
Location
Description
The Neugut wastewater treatment plant near Zurich was Switzerland's first full-scale municipal ozonation installation. Researchers sampled effluent at three stages — conventional treatment, ozone treatment, and biological post-treatment — to assess antibiotic-resistant bacteria and resistance genes. Ozonation substantially inactivated resistant bacteria and reduced intracellular resistance genes, but extracellular genetic material and treatment by-products were not fully addressed, and biological post-treatment requires separate evaluation.
Lessons learned
- Monitoring must distinguish viable resistant bacteria from intracellular and extracellular resistance genes, as ozonation affects these fractions differently.
- Ozonation should be evaluated as part of a sequential treatment train (ozone + biological post-treatment), not as a stand-alone barrier.
- Full-scale sampling across treatment stages provides more transferable evidence than laboratory removal tests alone.