DECOLORIZING DYE WASTE-WATER WITH FENTON REAGENT

Five types of simulated dye wastewater, separately prepared with disperse, reactive, direct, acid and basic dyes, were decolorized with a hydrogen peroxide-ferrous ion system, known as Fenton's reagent. The results are that the best pH value for decolorization is below 3.5, the average percent removal of chemical oxygen demand (COD) is about 90%, the transparency of wastewater is above 25 cm and the average percent decolorization is above 97%. All the results of treating the dye wastewater of actual dyeing and finishing mills are similar to those in the laboratory. Temperature mainly influences the speed of decolorization, i.e. the lower the temperature, the longer the time for decolorization.