Abstract: Waste liquid from bromine extraction was the mother liquid of sun salt water after potassium extraction and bromine extraction.Its mass concentration of MgCl2 reached 400~450 g/L，but the larger turbidity and chroma affected the quality of fine chemicals processed from it.So physical and chemical decolorizations were studied.Results showed that the color of bromine liquid waste was mainly composed of organic coloring substances；sand filtration effectively removed the suspended solids，reduced the turbidity from 40.9 NTU to about 2 NTU，but the decolorization rate was only about 41%； active carbon decolorization rate was 60%，the decolorization rates of both sand filtration and active carbon were not ideal. Under the best experimental conditions，the decolorization rates of NaClO and H2O2 were 80% and 79%，respectively，which achieved better decolorizaiton effect；comprehensive consideration of oxidation time and oxidation temperature，the decoloriation effect of NaClO was better than that of H2O2；the purification and decolorization technology of waste liquid of bromine system was pretreated by sand filtration and decolorized through NaClO，and the best decolorization conditions as follow：the adding amount of NaClO was 8%（mass fraction），pH=6.0，oxidation time was 40 min，and the decolorization rate was 80%.

Key words: waste liquid from bromine extraction, filtering, adsorption, oxidation, decolorization