Removal of a Toxic Anthraquinone Dye by Combination of Red Mud Coagulation and Ozonation

Abstract

Removal of a toxic anthraquinone dye—Disperse Blue 56 (DB56) by single red mud (RM) coagulation, single ozonation and combined RM coagulation/ozonation (RM/O3) was carried out in laboratory-scale experiments. RM/O3 treatment exhibited more effective in toxicity removal, color removal and chemical oxygen demand (COD) reduction than the other two methods. The effect of several operational parameters, including initial dye concentration, pH value, RM coagulant dose and O3 dose, on color removal and COD reduction was also investigated. Among these factors, pH value had the most important effect.