title: Degradation and estrogenic activity removal of 17beta-estradiol and 17alpha-ethinylestradiol by ozonation and O3/H2O2.
abstract: This work investigated the degradation of a natural (17beta-estradiol) and a synthetic (17alpha-ethinylestradiol) estrogens (pure or in the mixture) and the removal of estrogenic activity by the ozonation and O3/H2O2 process in three different pHs (3, 7 and 11). The effect of oxidation via OH radical was evaluated adding a radical scavenger (t-butanol) in the medium. Estrogenic activity was performed using the YES assay. 17beta-estradiol and 17alpha-ethinylestradiol presented similar estrogenic potential and the association of these estrogens resulted in an addictive effect for estrogenic activity. Ozonation and O3/H2O2 processes were effective in removing the estrogens in aqueous solution. In the mixture at pH 11, removals were higher than 98% and 96% for 17beta-estradiol and 17alpha-ethinylestradiol, respectively. In pH 3, 17beta-estradiol and 17alpha-ethinylestradiol removals were 100% and 99.7%, respectively. When estrogens were treated separately, the removals in pH 11 were superior to 99.7 and 98.8%, while in pH 3 were 100% and 99.5% for 17beta-estradiol and 17alpha-ethinylestradiol, respectively. 17alpha-ethinylestradiol has been always removed at lower rates (pure or in the mixture) for all applied conditions. Estrogenic activity was completely removed in pH 3 for ozonation or O3/H2O2. The samples oxidized in pH 11 presented higher estrogenic activity than those in pH 7. Estrogens removal was lower at pHs 7 and 11, when the scavenger was added to the media. The higher estrogen residual concentrations found in ozonation in presence of tert-butanol are contributing for higher estrogenic activity observed in pHs 7 and 11. By-products with estrogenic activity were formed by oxidation via OH radical. Only a few compounds could be identified in pHs 7 and 11 and they have a phenolic ring, which, probably is contributing to the estrogenic activity observed.
authors.affiliation: Chemical Engineering Program-COPPE, Federal University of Rio de Janeiro, P.O. Box 68502, 21941-972, Rio de Janeiro, RJ, Brazil.
authors.forename: Milena Guedes
authors.initials: MG
authors.lastname: Maniero
authors.forename: Daniele Maia
authors.initials: DM
authors.lastname: Bila
authors.forename: Márcia
authors.initials: M
authors.lastname: Dezotti
mesh_terms: D001681:Biological Assay; D004305:Dose-Response Relationship, Drug; D004958:Estradiol / Q000032:analysis* / Q000737:chemistry; D004997:Ethinyl Estradiol / Q000032:analysis* / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D010084:Oxidation-Reduction; D010126:Ozone / Q000737:chemistry*; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000378:metabolism; D013056:Spectrophotometry, Ultraviolet; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry; D018508:Water Purification / Q000379:methods*
chemical_list: D014874:Water Pollutants, Chemical; D004997:Ethinyl Estradiol; D004958:Estradiol; D010126:Ozone; D006861:Hydrogen Peroxide