Abstract: A cationic taro starch flocculant was prepared by using taro starch as raw material and 2,3-epoxypropyltrimethylammonium chloride (GTA) as cationic etherifying agent.Fourier transform infrared spectroscopy and scanning electron microscopy of flocculant were characterized.The adsorption properties of C.I.Direct Violet 1 and C.I.Disperse Blue 56 in water were investigated.When the dosage of the prepared starch flocculant was 0.6 g/L and 1.8 g/L,the adsorption equilibrium of C.I.Direct Violet 1 and C.I.Disperse Blue 56 was respectively reached,and the decoloration rate was above 90%.The adsorption behavior of C.I.Direct Violet 1 and C.I.Disperse Blue 56 on cationic taro starch conformed to the Langmuir isotherm.The adsorption was spontaneous endothermic reaction of single molecule layer.Among them,the adsorption of C.I.Direct Violet 1 was mainly chemical adsorption,and the adsorption of C.I.Disperse Blue 56 was mainly physical adsorption.

Key words: cationic taro starch, adsorption, C.I.Direct Violet 1, C.I.Disperse Blue 56