Evaluation of Bioassays and Wastewater Quality ... - Oekotoxzentrum

5.2. Estrogenicity during wastewater treatment
When looking at the improvement of wastewater quality regarding estrogenic substances (Figure
8), a strong decrease in estrogenicity could be detected with the Yeast Estrogen Screen (YES)
and the ER-CALUX assay at the Lausanne pilot study based on 17β-estradiol-equivalents
(EEQ).
Figure 8: Evolution of estrogenicity during wastewater treatment steps: Estradiol equivalent
concentrations [ng/L] and change indices (CITEQ) from the YES and the ER-CALUX assay for the 4 th MC.
CILF/EN Effect biological treatment, CIPAC/EN Overall effect biological treatment and PAC-UF treatment,
CIOZ/EN Overall effect biological treatment and ozonation, CIOZ+SF/EN Overall effect biological treatment and
ozonation+ sand filtration.
During biological treatment, estrogenicity decreased between 11 and 12 fold compared to the
influent, and during PAC-UF treatment or ozonation the concentrations decreased additionally
6 to 13 fold compared to the biological treatment.
5.3. Conclusions for the evaluation of wastewater quality regarding
micropollutants and their effects
The advanced treatment steps PAC-UF and ozonation led to a substantially lowered risk
potential for diclofenac, carbamazepin and clarithromycin. Additionally both treatments lowered
the estrogenicity between two or three orders of magnitude in comparison to the influent. PAC-
UF treatment and ozonation led to a 6 to 13 times lower estrogenicity compared to the biological
treatment.
In combination with the results of the performance analysis (chapter 4), for micropollutants and
estrogenic substances a significant reduction of risks can be expected with advanced
wastewater treatment.
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