Degradation of Free Estrogens and their Conjugates in Wastewater Treatment Process

This paper describes degradation characteristics of free estrogens and their conjugates in simulated membrane bioreactor (MBR). Hydraulic retention time (HRT) of aerobic section was set at 8 hours and aerobic solids retention time (A-SRT) was set at 60 days. Target substances were 17β-estradiol (E2), estrone (E1), 17α-ethynylestradiol (EE2), estriol (E3), estrone-3-sulfate (E1-S), β-estradiol 3-sulfate (E2-S), estriol 3-sulfate (E3-S), estradiol-3, 17-disulfate (E2-diS). Concentrations of target substances in influent and effluent were determined by LC/MS/MS. Concentrations of free estrogens were completely declined in aerobic wastewater treatment process, while estrogen conjugates remained in the effluent. Moreover we found that E1-S, E2-S and E3-S were degraded to some extent, while E2-diS was rather stable in the aerobic wastewater treatment process.