Advanced oxidation process for the removal of ionic liquids from water: The influence of functionalized side chains on the electrochemical degradability of imidazolium cations

► Electrochemical oxidation of ILs at PbO2 anode was very effective. ► ILs were mainly oxidized in indirect way. ► The mineralization process was more effective for ILs with the shorter side chain. ► Intermediates were produced by hydroxyl radical substitution to side chain of ILs. ► Another pathway of degradation was oxidative cleavage of the imidazolium ring.