Phenol-containing wastewater decolorization method

The invention relates to a phenol-containing wastewater decolorization method comprising the following steps: a formaldehyde solution is added to the phenol-containing wastewater for carrying out a condensation reaction; a condensation product is separated after the reaction, such that a filtrate is obtained; alkaline liquid is added into the filtrate for regulating the acidity of the wastewater; the obtained liquid is subjected to standing and stripping; activated carbon is added for decolorization; after decolorization, the activated carbon and various insoluble matters are removed by filtering, such that the wastewater is colorless; and the colorless wastewater is subjected to evaporation crystallization, such that an ammonium sulfate product with qualified nitrogen content and organic matter is obtained. The chromaticity of the phenol-containing wastewater before decolorization is 20000-50000, and the chromaticity of the wastewater after decolorization and before evaporation is 0-25. The method has a simple process. With the method, industrial phenol-containing wastewater can be effectively treated, and ammonium salt in the wastewater can be produced as a byproduct. The color of the wastewater is removed, and the stability of the quality of the ammonium sulfate product is ensured.