Decolorization of Crystal Violet by ultrasound/heterogeneous Fenton process.

Activated-carbon-supported iron oxides were prepared and used as a catalyst in an integrated ultrasound/heterogeneous Fenton process for the decolorization of Crystal Violet. A synergistic effect was observed when ultrasound was combined with the heterogeneous Fenton process. The decolorization efficiency increased with the increasing power density and catalyst dosage, but decreased with the increase of initial pH value. There exists an optimal hydrogen peroxide concentration for decolorization. Catalyst stability was evaluated by measuring iron leaching in solution. The decolorization efficiency was 88% under the optimal conditions. Toxicity test with Daphnia magna showed that the acute toxicity of dye solution decreased significantly after the treatment by the heterogeneous sono-Fenton process.