1. Ozonation of estrogenic chemicals in biologically treated sewage
Kamilla Hansen, Henrik R. Andersen and Anna Ledin

2. Chemicals found in sewage have hormonal activity
Parabens
Bisphenol A
Sunscreens
p-Nonylphenol
Steroid estrogens

3. Non-physiologic vitellogenin synthesis
Steroid estrogens in the water environment have effects on fish, amphibians and crustaceans
Non-physiologic vitellogenin synthesis
Gender determination
17b-estradiol

4. Ozone treatment of wastewater effluent
Figure from ITT/WEDECO sales material with permission by Achim Reid

5. Scheme of an ozone system
ozone generator
energy
(400 V)
cooling water °C
feed gas O3
grounded
air / O2
electrodes
5,5 kV
offgas
reaction tank
Figure from ITT/WEDECO sales material with permission by Achim Reid

6. The ozone experiments Effluent collected from: Estrogen concentration:
Usserød WWTP (low COD)
Lynetten WWTP (medium COD)
Estrogen concentration:
Xeno 1 µg/L
Steroid 40 ng/L
Ozone dose: 1-9 g/m³
Reactor:
Height 50 cm
Volume 2.0 L

7. Removal of estrogens
The removal ( ) of estrogens from Usserød WWTP

8. Estrogen potency with YES assay

9. Electric Energy per Order
Definition:
The electric energy consumed per unit volume of water treated required for 90 % removal of the investigated compound (Bolton et al., 2001)
where Ci and C is the initial and the final concentration, respectively, EED is the electrical energy dose in kWh/m³ and EEO is the electric energy per order

10. Electric Energy per Order
The removal efficiency for ethylparaben (EP), 3-(4-Methylbenzyliden)camphor (4-MBC), Octylphenol (OP), and Estradiol (E2) in treated sewage from Usserød (open symbols) and Lynetten (closed symbols) WWTPs as function of electric energy dose applied.

11. Electric Energy per Order
EEO in kWh/m³

12. Structures of selected estrogenic chemicals
isoBP
BPA
4-MBC
EE2

13. Calculation example
Concentration of ethynyl estradiol (EE2) in wastewater effluent is up to 1.4 ng/L
A likely quality criteria is 0.35 ng/L
 75% removal is required
EEO for EE2 in effluent from Usserød WWTP is 0.20 kWh/m³

14. Full scale estimations
EEOfull scale = 0.3·EEOexperimental
kWh/m³ = 0.3 · kWh/m³
EEO for other treatment methods
UV: 6-28 kWh/m³
UV/H2O2: 2-9 kWh/m³

15. Change in UV-absorbance
The absorbance of untreated subtracted the absorbance of the treated water
The absorbance of the waste-water as function of ozone dose applied

16. Removal of compound vs. absorbance
The correlation between the removal of methyl-paraben (circles) and bisphenol A (squares) and the removal of the absorbance at 254 nm in the effluent from Usserød WWTP.

17. Measurement of absorbance
UV meter
UV meter O3
Figure from ITT/WEDECO sales material

18. Conclusion
A relation between the ozone dose and the removal of a range of estrogenic compounds in two different biologically treated sewage has been found
The correlation between energy dose and removal was found and the electric energy required to remove 90% of the compound was determined.
Both types of effluent waters showed a linear correlation between the absorbed ozone dose and the decolourisation. Consequently there are also a correlation between the decolourisation and removal of the test chemicals
The difference in UV-absorbance at 272 nm over the ozone reaction chamber may be useful for feedback control of the ozone generator output in order to optimize the ozone dose for ozonation of effluents