Abstract: A self-developed granular complex bentonite were cooperated with surfactant cetyltrimethylammonium chloride (CTAC) to decolorize indigo carmine simulated wastewater.The effect of dosage of granular complex bentonite and surfactant,length of time for oscillating,pH,temperature,initial concentration of indigo carmine simulated wastewater,etc.on decolorization rate was investigated,as well as recycling effect of granular complex bentonite,the function of which during decolorization was researched according to experimental phenomenon.The results showed that initial concentration and pH of indigo carmine solution had little effect on the decolorization rate while temperature can greatly affect decolorization.The decolorization rate of indigo carmine wastewater could be up to 100% under right conditions.Granular complex bentonite could enhance the flocculation of acid indigo carmine,which could significantly improve the decolorization effect.Granular complex bentonite could easily regenerate and be used for four times.Not only well treatment effect could be achieved,but also it owns the excellent characteristics of easy separation of solid and liquid,less dosage of surfactant,low risk of secondary pollution,easily regeneration for granular complex bentonite,etc.excellent characteristics could be achieved when granular complex bentonite is cooperated with surfactant CTAC for decolorization treatment.

Key words: Granular complex bentonite, Cetyltrimethylammonium chloride surfactant, Acid indigo carmine wastewater, Decolorization