Flocculation of Quaternary Chitosan on Acid Dyeing Waste Water

In order to increase the positively charge, solubility in water and grafted degree of chitosan, quaternary chitosan was synthesized with chitosan and glycidyl-trimethyl-ammonium chloride by the heterogeneous reaction. FT-IR was used to characterize the structure of the synthesized. The quaternary chitosan was then used to treat simulated acid dyeing wastewater, the effect of quaternary chitosan concentration, agitation mode and pH values on flocculation were discussed. The results indicated that the H+ in nucleophilic center-NH2 was displaced by-CH2CH(OH)CH2N+(CH3)3 and the 2-hydroxypropyltrimethyl ammonium chloride chitosan (quaternary chitosan) was synthesized. When applied to treatment of acid dye waste water, the decolorization rate was 95.5%, and the COD removal was 86.4%.