羧甲基壳聚糖季铵盐的制备及混凝性能研究  

Preparation and Flocculation Properties of Quaternized Carboxymethyl Chitosan

作　　者：焦淑芳[1] 李瑾[1,2] 马启敏[1,2] 

机构地区：[1]中国海洋大学环境科学与工程学院,山东青岛266100 [2]中国海洋大学海洋环境与生态教育部重点实验室,山东青岛266100

出　　处：《中国海洋大学学报（自然科学版）》2013年第2期72-76,共5页Periodical of Ocean University of China

基　　金：国家水体污染控制与治理科技重大专项(2008ZX07106-003);国家自然科学基金项目(41106067);山东省自然科学基金项目(ZR2010BQ013);中国海洋大学中央高校基本科研业务费专项资金项目(201013032)资助

摘　　要：采用氯乙酸为羧甲基化试剂、3-氯-2-羟丙基三甲基氯化铵为季铵阳离子化试剂,制备了羧甲基取代度为64.4%,季铵化取代度为98.4%的羧甲基壳聚糖季铵盐。采用zeta电位和烧杯混凝实验研究了羧甲基壳聚糖季铵盐对高岭土模拟水样的混凝特性,考察了pH值、混凝剂投加量和原水浊度对混凝效果的影响。结果表明,羧甲基壳聚糖季铵盐可以明显改善高岭土悬浊液的混凝效果;达到最佳混凝效果时所需羧甲基壳聚糖季铵盐的投加量随高岭土悬浊液pH值和原水浊度的增加而增加。浊度去除率随pH值的增加而减小,随原水浊度的增加而增加;原水浊度为50NTU时,浊度去除率均小于80%;羧甲基壳聚糖季铵盐具有两性混凝剂的典型特性,吸附架桥和电性中和是羧甲基壳聚糖季铵盐的主要混凝作用机理,混凝过程是多种机制共同作用的过程。A new approach to preparation of chemically modified carboxymethyl chitosan （CM） derivatives was reported, where CM was prepared from chitosan with chloroactic acid as the carboxymethyl reagent first, and then N-quaternary ammonium group was introduced by the reaction of CM with 2,3-epoxypropyl trimethyl-ammonium. The degree of substitution （DS） of carboxymethyl group was 64.4% and the DS of the quaternization group was 98. 4%. The floeculation properties of quaternized carboxymethyl chitosan （QCMC） are investigated using kaolinite suspension as simulated water by jar test and zeta potential. The effects of pH value, dosage of quaternized carboxymethyl chitosan, and initial turbidity on the flocculation properties are investigated in detail, respectively. The results indicated that QCMC showed notable improvement in flocculation properties of kaolinite suspension in the whole pH range. The optimal dosage of QCMC increased with increasing pH value and initial turbidity. Turbidity removal was adverse to the pH value while proportional to initial turbidity. Turbidity removal was less than 80% when initial turbidity was 50NTU. QCMC had typical character of amphoteric flocculant. It was presumed that the flocculation induced by QCMC was dominated by bridging and charge neutralization flocculation mechanism. The flocculation process was Simultaneously responsible for the two kinds of driving forces.

关 键 词：壳聚糖 羧甲基壳聚糖季铵盐 高岭土 混凝性能 

分 类 号：O611.65[理学—无机化学]