The degradations of an anthraquinone dye, the reactive blue 4 (RB4), were studied by wet air oxidation (WAC). wet peroxide oxidation (WPO), photocatalytic oxidation, and electro-Fenton (EF) advanced oxidation. The RB4 oxidation was evaluated by the decrease in total organic carbon (TOC) content and concentration. The most efficient method for mineralization of RB4 was WPO, but in all methods TOC removal efficiency was above 75% after 60 min of treatment. (C) 2009 Elsevier B.V. All rights reserved.