秸秆两性纤维素絮凝剂的辐射法制备及应用研究

Study on preparation and application of amphoteric cellulose

以小麦秸秆纤维素与氯乙酸和2,3-环氧丙基三甲基氯化铵(GTA)为原料,用微波辐射法扩大纤维素的活化面积,合成两性离子型纤维素絮凝剂。秸秆两性离子型纤维素絮凝剂的最佳制备条件是:①纤维素羧甲基化:秸秆粉5 g,醚化剂6 g,乙醇浓度为70%,辐射时间为9 min,碱用量为5 g,醚化温度80℃;②季铵基化:取代度为1.16的羧甲基纤维素钠3 g,环氧丙基三甲基氯化铵5.5 g,80%的异丙醇溶液50 mL,10%的NaOH水溶液45 mL,醚化温度80℃,微波辐射10 min,反应时间5 h。在上述条件下,合成的两性纤维素絮凝剂中羧甲基取代度DS为1.16,季铵基取代度DS为1.12。絮凝实验结果表明,制备的纤维素两性离子絮凝剂在温度30℃下,pH=8,絮凝剂用量0.35 g/100 mL处理污水时,透光率可达到70%以上,絮凝效果理想。

After being basified, amphoteric hydroxyethylcellulose was obtained by straw cellulose as raw material reacting with chloroacetic acid, then with 2,3-epoxypropyl trimethyl ammonium chloride （ GTA）, which by microwave radiation method to expand cellulose activation area to synthesis of amphoteric cellulose, a new flocculant. The sodium carboxymethyl cellulose synthesis in the optimum conditions were that straw powder was 5 g,chioroacetic acid 6 g,70% aqueous ethanol solution, radiation time 9 rain, NaOH 5 g, reaction temperature 80℃. The optimum conditions of quaternization of sodium carboxymethyl cellu- lose were that sodium carboxymethyl cellulose （ DS 1.16）3 g, epoxy propyl three methyl ammonium chloride 5.5 g,80% of isopropyl alcohol aqueous solution 50 mL, 10% NaOH aqueous solution 45 mL,reaction temperature 80℃ ,radiation time 10 rain ,reaction time 5 h. Under the condition of described above, synthetic amphoteric cellulose flocculant carboxymethyl degree of substitution was 1.16, and the quaternary ammonium group degree of substitution was 1.12. The practical treatments were studied by using the new flocculant to dispose of effluents. The flocculation experimantal results showed that the optimum conditions were found as follows： temperature 30℃, pH = 8, the suitable ratio of solid to liquid at 0.35 g/100 mL. Under these conditions,light transmission rate is more than 70% ,the flocculation effect was satisfied.