Mechanisms and factors affecting the adsorption of sodium alginate onto modified clays

作     者：林勇新 曹西华 宋秀贤 王楠 俞志明 

作者机构：Key Laboratory of Marine Ecology and Environmental SciencesInstitute of OceanologyChinese Academy of Sciences University of Chinese Academy of Sciences 

出 版 物：《Chinese Journal of Oceanology and Limnology》 (中国海洋湖沼学报（英文版）)

年 卷 期：2013年第31卷第4期

页      面：867-875页

核心收录：

学科分类：0710[理学-生物学] 083002[工学-环境工程] 0830[工学-环境科学与工程（可授工学、理学、农学学位）] 0908[农学-水产] 0707[理学-海洋科学] 08[工学] 0815[工学-水利工程] 

基　　金：Supported by the National Natural Science Foundation of China for Young Scholars(No.40906055) the National Natural Science Foundation of China for Creative Research Groups(No.41121064) the National Basic Research Programof China (973 Program) (No.2010CB428706) 

主　　题：modified clays sodium alginate adsorption kinetics adsorption isotherms pH ionic strength 

摘      要：Algal organic materials （AOMs） are one critical factor affecting the efficiency of modified clays used for the mitigation of harrnful algal blooms （HABs）. This study was conducted to develop a deeper understanding of the mechanisms and factors affecting the adsorption of AOMs onto modified clays. Sodium alginate （polysaccharide） and kaolinite modified with polyaluminium chloride （PAC1） were used as AOMs and modified clay model substances, respectively, and the effects of modifier dosage, contact time, solution pH and ionic strength were investigated through batch adsorption experiments. Kinetics revealed that the alginate adsorption rate was described well by a pseudo-second order model. PACl effectively enhanced the adsorption capacity of kaolinite and increased the adsorption rate, and the optimum additive amount of PACl was 5%. The experimental data fitted both the Freundlich and Langmuir adsorption equations well. The adsorption thermodynamics for alginate onto modified clays suggests that alginate adsorption is a spontaneous process. The adsorption of alginate onto modified clays was highly dependent on pH, with a decrease in adsorption observed with increased pH to 9.48, but the opposite was true above pH 9.48. Finally, adsorption increased with increasing ionic strength.