AWWA WQTC64032

This study investigated the removal of estrogenic activity during oxidative treatment of water containing the oral contraceptive 17a-ethynylestradiol (EE2). Six different oxidants, ozone, chlorine dioxide, ferrate, hydroxyl radical, chlorine, and bromine, were considered. First, the effect of sub-stoichiometric doses of each oxidant on the estrogenic activity of aqueous solution of EE2 was studied to test whether initial transformation of EE2 results in a substantial removal of estrogenic activity. For the six investigated oxidants, the reduction of estrogenic activity was generally proportional to the decrease of EE2 concentration. This indicates that either the estrogenic activity of the intermediates of the initial transformation step is much lower than that of EE2 or these initial intermediates are further oxidized rapidly. Various oxidation products formed during oxidation of EE2 were identified. The estrogenic activity and oxidation kinetics of these products were also measured. The relative estrogenic activity of various oxidation products reveals that only small modifications of the phenol ring results in a substantial reduction of the estrogenicity of EE2. Overall, this study demonstrates that oxidative water treatment is a promising tool for the control of phenol-containing estrogens in drinking water and wastewater. Includes 17 references, table, figures.