Abstract:17α ethynylestradiol (EE2) is the strongest estrogenic endocrine disrupting chemical, and it is hardly biodegradable. It can be removed by adsorption due to its hydrophobic property. The absorptive removal of EE2 is comparatively studied by pumping EE2 solution(5.0 μg/L) into upstream reactors, packed with granular activated carbon (GAC), manganese oxide (MnO2) and wool fiber respectively. The GAC reactor removes 99.8% EE2 without breakthrough, and the breakthrough in the MnO2 reactor happens after 8 days. Although the absorbability of wool fiber is higher than MnO2, the breakthrough in the wool fiber reactor happens after 12 hours. This lies in that the bulk density of wool fiber (10~20 kg/m3) is lower than that of MnO2 (1 900~2 000 kg/m3). A practically used wool fiber reactor may take more time to breakthrough due to the approximately three orders of magnitude lower EE2 concentration in the secondary effluent than that in these experiments, which is proved by the following pilot scale experiments.