In this study, the fate and behavior of typical endocrine disrupters in wastewater treatment plants of two different treatment processes were investigated for more than one year. All the investigated endocrine disrupters were effectively removed by the wastewater treatment processes. It was considered that the majority of the removal was accomplished by the biological treatment processes. The removal efficiencies of estrone (E1) and 17β-estradiol (E2) in the oxidation ditch process were higher than those in the conventional activated sludge process. The removal efficiency of E1 was lower than those of E2 and E3. In particular, in the conventional activated sludge process, E1 concentrations in effluents were higher than those in influents in many cases. It seems that the cleavage of conjugated estrogen is responsible for the increase in E1 concentration. On the other hand, estrogen-like activity was also effectively removed in the wastewater treatment processes. The estrogen-like activity in effluents was mainly derived from E1 and E2, and the contribution of E1 was particularly high. These results suggest that E1 is very important for the effective removal of estrogenic potency in effluents.
