Removal of 26 corticosteroids, potential COVID-19 remedies, at environmentally relevant concentrations in water using UV/free chlorine, UV/monochloramine, and UV/hydrogen peroxide

Corticosteroids (CSs) with two double bonds in ring A are sensitive to UV. CSs were poorly removed by individual Cl 2 , NH 2 Cl, and H 2 O 2 treatment. Combining UV with Cl 2 , NH 2 Cl, or H 2 O 2 promoted UV-insensitive CS removal.