Abstract: The application of the chitosan in flocculation is limited by its poor water solubility and low charge density. Chemical modifications of the chitosan can improve its water solubility and flocculation performance. The formation of Schiff base (B-CTS) by the chitosan and the benzaldehyde protects the amino group of the chitosan. Then B-CTS is reacted with the succinic anhydride to synthesize succinyl chitosan (SACTS) and further reacted with dimethyl diallyl ammonium chloride (DMDAAC) to synthesize succinyl chitosan quaternary ammonium salt (SAQCS). The structure and morphology of SAQCS were characterized by FTIR, 1HNMR, XRD, and ESEM. The effects of initiator dosage, monomer ratio, reaction temperature and reaction time on the cationic degree of SAQCS were discussed. The results showed that the optimum conditions were as follows:the initiator dosage was 2%, the m(DMDAAC)/m(SACTS)=5.4, the reaction temperature was 70℃, and the reaction time was 7h. Under those process conditions, the cationic degree of SAQCS was 42.26%. The flocculation experiment of SAQCS, CTS, CPAM and Kaolin simulated wastewater was carried out. The effects of H, dosage and temperature on flocculation were investigated. The results showed that the turbidity removal rate of supernatant was above 96% after flocculation when the flocculation conditions were pH=2-5, the dosage was 3-9mg/L, and the temperature was 25-50℃.

Key words: chitosan, amino protection, biomass, flocculation, Kaolin

摘要： 壳聚糖由于水溶性差、电荷密度低等缺点，使其在絮凝应用方面受到限制。对壳聚糖进行化学改性，可以改善其水溶性和絮凝性能。本文采用苯甲醛保护壳聚糖氨基，然后与丁二酸酐反应合成琥珀酰壳聚糖（SACTS），进一步与二甲基二烯丙基氯化铵（DMDAAC）反应合成琥珀酰壳聚糖季铵盐（SAQCS）。采用FTIR、¹H NMR、XRD、ESEM等方法对SAQCS的结构和形貌进行表征。探讨了引发剂用量、单体配比、反应温度、反应时间对SAQCS阳离子度的影响。结果表明，SAQCS较优合成工艺条件为：引发剂用量（占单体的质量分数） 2%，m（DMDAAC）/m（SACTS）=5.4，反应温度70℃，反应时间7h。此工艺条件下合成的SAQCS的阳离子度为42.26%。将SAQCS、壳聚糖、聚丙烯酰胺与配制的高岭土模拟废水进行絮凝实验，考察了pH、投加量、温度对絮凝效果的影响。结果表明，当絮凝条件为pH=2～5、投加量3~9mg/L、温度25～50℃范围内，使用SAQCS絮凝后上清液浊度去除率均在96%以上。

关键词: 壳聚糖, 氨基保护, 生物质, 絮凝, 高岭土