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

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

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

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

Scheme of an ozone system ozone generator energy (400 V) cooling water 5 - 32 °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

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

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

Estrogen potency with YES assay

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

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.

Electric Energy per Order EEO in kWh/m³

Structures of selected estrogenic chemicals isoBP BPA 4-MBC EE2

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

Full scale estimations EEOfull scale = 0.3·EEOexperimental 0.4-0.33 kWh/m³ = 0.3 · 0.14-1.1 kWh/m³ EEO for other treatment methods UV: 6-28 kWh/m³ UV/H2O2: 2-9 kWh/m³

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

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.

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

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