Naturally occurring DOM was more photoreactive than wastewater-derived DOM in ice.

The photodegradation rates of UV-254 and THMFP were higher than DOC in ice.

The photodegradation rates of DOM in ice were negatively correlated to DOC level.

NO₃⁻${{\text{NO}}_3}^{-}$, NO₂⁻${{\text{NO}}_2}^{-}$, Fe³⁺ and Fe²⁺ accelerated the photodegradation of DOM in ice.

Cl⁻ and Cu²⁺ inhibited the photodegradation of DOM in ice.