Flocculation properties of biodegradable amphoteric chitosan-based flocculants
Flocculation properties of biodegradable amphoteric chitosan-based flocculants
复制标题
可生物降解两性壳聚糖基絮凝剂的絮凝性能
DOI：
10.1016/j.cej.2011.05.106
复制
发表时间：
2011-08
影响因子：
15.1
通讯作者：
Qian, Xiaozhi
中科院分区：
文献类型：
--
作者：
Cheng, Rongshi;Shang, Yabo;Lu, Yaobo;Chen, Yichun;Huang, Xin;Chen, Aimin;Jiang, Yuxiang;Gu, Wei;Qian, Xiaozhi
本研究制备了一种两性壳聚糖基絮凝剂（3-氯-2-羟丙基三甲基氯化铵（CTA）改性羧甲基壳聚糖，记为CMC-CTA）。两性絮凝剂与壳聚糖和阳离子壳聚糖相比，在整个pH范围内的溶解度和耐盐性均有显著提高。对CMC-CTA的絮凝性能进行了实验室和中试研究。在烧杯实验中，以高岭土悬浮液为合成水。考察了原水的pH、温度和原始浊度对投加量和絮凝性能的影响。在pH低于CMC-CTA等电点和高于CMC-CTA等电点时，投加量分别为0.03 ~ 0.20mg/L和0.8 ~ 1.0mg/L时絮凝效果最佳。从高分子絮凝剂的形态和絮凝动力学两个方面详细讨论了絮凝机理：溶液中高分子链的形状和电荷对最终絮凝性能影响较大；絮凝动力学与颗粒碰撞模型吻合较好。并利用中国长江镇江段原水，在中试规模上进一步研究了絮凝性能。通过正交试验研究了投加量、沉降时间和机械搅拌速率对絮凝性能的影响。得到了最佳实验条件。与镇江水厂目前使用的最佳投加量为40mg/L的聚合硫酸铁絮凝剂相比，CMC-CTA值（1.1mg/L）明显降低。综上所述，实验室和中试规模的絮凝实验均表明，两性壳聚糖基絮凝剂在较宽的pH范围内具有良好的絮凝性能。
In this study, a kind of amphoteric chitosan-based flocculants (3-chloro-2-hydroxypropyl trimethyl ammonium chloride (CTA) modified carboxymethyl chitosan, denoted as CMC-CTA) have been prepared. The amphoteric flocculants showed notable improvement in solubility and salt-resistance in the whole pH range compared with its precursors, i.e., chitosan and cationic chitosan. The flocculation properties of CMC-CTA were systematically studied at both the laboratory and pilot scales. At laboratory scale, kaolin suspension was employed as synthetic water in the beaker experiment. The effects of pH, temperature, and original turbidity of untreated water on the dosage and flocculation performances were investigated, respectively. At pH below and above the isoelectric point of CMC-CTA, the optimal flocculation performances were obtained with a dosage of 0.03–0.20mg/L and 0.8–1.0mg/L, respectively. The flocculation mechanism was discussed in detail from the morphologies of polymeric flocculants and flocculation kinetics: The shape and charge of polymer chains in the solution greatly influenced the final flocculation performances; The flocculation kinetics agreed well with the particle collision model. Moreover, raw water from the Zhenjiang part of the Yangtze River in China was used for the further investigation of the flocculation properties at the pilot scale. The influences of dosage, sedimentation time, and mechanical mixing rate to the flocculation properties were studied by orthogonal testing. The optimal experimental condition was then obtained. Compared with the currently used flocculants in the Zhenjiang Water Factory, i.e., polyferric sulfate, which has an optimal dosage around 40mg/L, the value of CMC-CTA (1.1mg/L) decreased greatly. Above all, the flocculation experiments at the laboratory and pilot scales both indicate that the amphoteric chitosan-based flocculants have good flocculation performances in a wide pH range.
登录
查看更多内容
影响因子：
11.2
作者：
A. Sand;M. Yadav;D. Mishra;K. Behari
通讯作者：
A. Sand;M. Yadav;D. Mishra;K. Behari
影响因子：
9.9
作者：
K. Das;P. Somasundaran
通讯作者：
K. Das;P. Somasundaran
影响因子：
3.3
作者：
Vandamme, Dries;Foubert, Imogen;Muylaert, Koenraad
通讯作者：
Muylaert, Koenraad
影响因子：
11.4
作者：
M. C. Garcia;A. Szogi;M. Vanotti;John P. Chastain;Patricia Millner
通讯作者：
M. C. Garcia;A. Szogi;M. Vanotti;John P. Chastain;Patricia Millner
影响因子：
3
作者：
Dating Tian;Xiong Wu;Cheng-Mei Liu;H. Xie
通讯作者：
Dating Tian;Xiong Wu;Cheng-Mei Liu;H. Xie