Photo-degradation of C.I. Disperse Blue 56 by UV irradiation combined with manganese minerals.

Photo-degradation of C.I. Disperse Blue 56 (DB56) by UV irradiation combined with manganese minerals (UV/MM) was investigated in this paper. Through comparative study with the UV/titanium dioxide (TiO2) process, it was found that the UV/MM method had similar photodegradation efficiency to UV/TiO2 and was slightly more effective in removing the toxicity. In the conditions of DB56 concentration = 400 mg/L, pH = 9.0, manganese minerals dosage = 20 g/L, room temperature (25 degrees C), dissolved oxygen (O2) = 50 L/h, and reaction time = 1 hour, the color and chemical oxygen demand removal percentages were up to approximately 94 and 51%, respectively. The results of this study indicate that UV/MM is an alternative approach that should be explored further in the treatment of dyeing wastewaters.