聚木糖的羧甲基化及用于模拟印染废水脱色的研究

Preparation of Carboxymethylated Xylan and Its Application in Decoloring of Simulated Dyeing Wastewater

以桦木聚木糖为原料,以氯乙酸钠为醚化剂,进行了聚木糖的羧甲基化研究。利用红外光谱以及核磁碳谱对羧甲基化聚木糖进行了结构表征。研究结果表明,成功制备了电荷密度为4.54 m mol/g、取代度为0.94的羧甲基聚木糖。本文还对羧甲基化后的聚木糖用于模拟印染废水的脱色性能进行了探讨。发现,乙基紫染料浓度为20mg/L时,最佳的脱色工艺条件为温度40℃,羧甲基聚木糖用量50 mg/L,p H值9,混合时间40 min,在上述工艺条件下,该模拟印染废水的脱色效率能达到97.1%。

Carboxymethylated xylan which has the charge density of 4. 54 mmol/g and the degree of substitution of0. 94 was successfully synthesized with birch xylan as the material,sodium chloroacetate as etherifying agent in this paper. The results of FT- IR showed that carboxymethylated xylan appeared the characteristic peaks of carboxyl groups in the vicinity of 1605 cm-1、1418 cm-1 and 1324 cm- 1.13C- NMR spectrum also appears a new peak at177. 6 ppm,which is caused by carboxyl groups of carboxymethylated xylan. The resultant carboxymethylated xylan was used for decoloring the simulated dyeing wastewater,and the optimized conditions for the discoloration are 40℃,carboxymethylated xylan concentration of 50 mg/L,p H 9,and mixing time of 40 min. At these optimum conditions,the decolorizing efficiency can reach 97. 1%.