Preparation of Carboxymethyl Chitosan and Study on the Decolorization of Dyeing Wastewater

The preparation of the carboxymethyl chitosan coagulant by orthogonal experiment was studied,and the product was used in discoloration of dyeing wastewater.The influences of various factors on flocculating ability were investigated.The results showed that the product with best properties was obtained with 5g chitosan,45% NaOH is 32 ml,sodium chloroacetate is 12g,reaction time is 3h and reaction temperature is 60℃.The optimal flocculation conditions in experiments with dyeing wastewaters of methylene blue trihydrate are that natural temperature,Carboxymethyl chitosan dosage is 200mg/L;pH value is 6,with a rate of decoloration over 89% after being treated for only 2 hours.