Cationic content effects of biodegradable amphoteric chitosan-based flocculants on the flocculation properties  

作　　者：Zhen Yang Yabo Shang Xin Huang Yichun Chen Yaobo Lu Aimin Chen Yuxiang Jiang Wei Gu Xiaozhi Qian Hu Yang Rongshi Cheng 

机构地区：[1]State Key Laboratory of Pollution Control and Resource Reuse,School of the Environment,School of Chemistry&Chemical Engineering,Nanjing University,Nanjing 210093,China [2]Zhenjiang Water Supply Company,Zhenjiang 212009,China

出　　处：《Journal of Environmental Sciences》2012年第8期1378-1385,共8页环境科学学报（英文版）

基　　金：supported by the Key Natural Science Foundation of China (No. 51073077,50938004,50825802);the Research Project of Ministry of Housing and Urban-Rural Development of China (No. 2009-K7-11);the Open Fund from State Key Laboratory of Pollution Control and Resource Reuse of Nanjing University (No.PCRRF11004);the Fundamental Research Funds for the Central Universities (No. 1105020504,1116020510);the Scientific Research Foundation of Graduate School of Nanjing University (No. 2012CL06)

摘　　要：A series of biodegradable amphoteric chitosan-based flocculants （3-chloro-2-hydroxypropyl trimethyl ammonium chloride （CTA） modified carboxymethyl chitosan, denoted as CMC-CTA） with different substitution degrees of CTA were prepared successfully. The content of carboxymethyl groups in each CMC-CTA sample was kept almost constant. The solubility of the various flocculants showed that, higher cationic content of flocculants caused a better solubility. The flocculation experiments using kaolin suspension as synthetic water at the laboratory scale indicated that the substitution degree of CTA was one of the key factors for the flocculation properties. With the increase of cationic content, the flocculants were demonstrated better flocculation performance and lower dosage requirement. Flocculation kinetics model of particles collisions combining zeta potential and turbidity measurements was employed to investigate the effects of the cationic content of the flocculants on the flocculation properties from the viewpoint of flocculation mechanism in detail. Furthermore, flocculation performance using raw water from Zhenjiang part of Yangtze River at the pilot scale showed the similar effects to those at the laboratory scale.A series of biodegradable amphoteric chitosan-based flocculants （3-chloro-2-hydroxypropyl trimethyl ammonium chloride （CTA） modified carboxymethyl chitosan, denoted as CMC-CTA） with different substitution degrees of CTA were prepared successfully. The content of carboxymethyl groups in each CMC-CTA sample was kept almost constant. The solubility of the various flocculants showed that, higher cationic content of flocculants caused a better solubility. The flocculation experiments using kaolin suspension as synthetic water at the laboratory scale indicated that the substitution degree of CTA was one of the key factors for the flocculation properties. With the increase of cationic content, the flocculants were demonstrated better flocculation performance and lower dosage requirement. Flocculation kinetics model of particles collisions combining zeta potential and turbidity measurements was employed to investigate the effects of the cationic content of the flocculants on the flocculation properties from the viewpoint of flocculation mechanism in detail. Furthermore, flocculation performance using raw water from Zhenjiang part of Yangtze River at the pilot scale showed the similar effects to those at the laboratory scale.

关 键 词：amphoteric chitosan-based flocculants substitution degree of CTA flocculation kinetics and mechanism 

分 类 号：TQ323.8[化学工程—合成树脂塑料工业] X703.5[环境科学与工程—环境工程]