Evaluation of Bioassays and Wastewater Quality ... - Oekotoxzentrum

To evaluate the efficiency of advanced treatment steps in reducing the biological effects of
micropollutants with specific modes of action, the use of in vitro bioassays with sample
enrichment is highly promising. However, some of the available test protocols are not certified.
Therefore it should be aimed for a standardization and certification of those tests. Additionally, a
cost efficiency analysis should be performed.
For an effect assessment for whole organisms, chronic in vivo bioassays are desirable. Here is a
need for the development of tests especially with sensitive test organisms. For those assays the
costs are often much higher than for small-scale / in vitro bioassays. Furthermore, the
interpretation of observed effects in in vivo bioassays generally is more difficult, especially with
regard to micropollutants. Regarding bioassays with vertebrates there is also a need to reduce
the use of animals in experimentation.
Overall the performance review with bioassays has shown that ozonation-SF and PAC-UF
treatment are useful measures to reduce the effects of micropollutants in waterbodies. A broad
range of micropollutants and their effects were eliminated by more than 80%, and there was no
evidence for a toxicity increase due to a constant formation of stable toxic ozonation by-products.
In vitro bioassays based on specific effects with sample enrichment were generally deemed
more suitable for the performance assessment of advanced wastewater treatments than
integrative in vivo bioassays without sample enrichment.
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