Assistance and acceleration of the environment's self-remediation of pollutants represent an important and long-standing goal for environmental chemistry communities. Here, a degradation route using a combination of a nitrite and a ferric salt as the photocatalyst is presented for catalytically removing 17beta-estradiol (E2), estriol (E3), and 17alpha-ethynylestradiol (EE2) in water under mimicked natural environmental conditions, i.e., in the phytotron. After a 1 day reaction, 86.6% of the estrogen E2 was degraded. Extending the incubation time to 30 days, more than 99.9% E2 was removed and a very small quantity of malonic acid observed as the residual organic compound, and estrogenic activity was determined. The results showed that the estrogenic activities of the intermediate products are negligible and that there is no secondary risk associated with increased the estrogenic activity. The degradation system demonstrated that FeCl3/NaN02 is an efficient photocatalyst which is active on natural light irradiation. This work highlights a promising development for in situ treatment of pollutants in natural-environment conditions.