N,O-羧甲基壳聚糖的制备及其在印染废水处理中的应用研究

Study on preparation of N,O-carboxymethy chitosan and its application in dyeing wastewater treatment

研究了羧甲基壳聚糖(CMC)的最佳制备工艺及其在印染废水处理中的应用.CMC的最佳制备工艺条件为:加入8mL浓度为15mol/L NaOH溶液,碱化2h后,在微波功率400W条件下,加入ClCH2COOH溶液(7mol/L)8mL,微波辐射时间为20min,加热温度为60℃时,反应产物取代度(DS)最高为0.89;该产品的等电点为5.63.试验研究了CMC用量、处理时间以及pH值对印染废水COD去除率的影响.研究表明:CMC用量25mL、处理时间3h、pH值为5.0时,CMC对印染废水的COD去除率较高.

The optimal preparation conditions of the N,O-carboxymethy chitosan （CMC） and its application in dyeing wastewater treatment were studied. The results showed that the optimal preparation conditions were as follows： 8 mL of 15 mol/L sodium hydroxide solution was added and alkalified 2 h, 8 mL of chloroacetic acid （7 mol/L） was added under 400 W of microwave power for 20 rain of irradiation time, reaction temperature 60℃, the highest degree of substitution （DS） of reacted product was 0.89, and the isoelectric point of the product was 5.63. The removal-rate of COD to dyeing-wastewater was studied under different dosage of CMC, pH, treatment time. The effects of CMC dosage, treatment time and pH on the COD removal rate were investigated. The results showed that the removal rate of COD was higher with CMC dosage 25 mL and treatment time 3 h, pH value 5.0.