上海海洋大学学报2012，Vol.21Issue(5)：800-808,9.
镧改性沸石对水中磷酸盐和铵的去除性能
Removal of phosphate and ammonium from aqueous solution by lanthanum-modified zeolite
摘要
Abstract
In this study,lanthanum-modified zeolite(LaMZ) was used as an adsorbent to remove phosphate and ammonium from aqueous solution.The effects of various parameters such as adsorbent dosage,solution pH,reaction time,initial adsorbate concentration,temperature,ion strength and coexisting ions on the removal of phosphate and ammonium by LaMZ were investigated using batch experiments.Results showed that LaMZ was effective for the removal of phosphate and ammonium from aqueous solution.The kinetic studies showed that the adsorption of phosphate and ammonium onto LaMZ could be described by a pseudo-second-order kinetic model.The equilibrium adsorption data of phosphate on LaMZ fitted well with the Langmuir isotherm model,and the equilibrium adsorption data of ammonium on LaMZ fitted well with the Langmuir,Freundlich and Dubinin-Radushkevich isotherm models.The thermodynamic studies revealed that the adsorption of phosphate and ammonium on LaMZ was spontaneous and endothermic process.The phosphate adsorption capacity for LaMZ decreased gradually with increasing pH from 3 to 10,but decreased greatly with increasing solution pH from 10 to 12.The ammonium adsorption capacity for LaMZ was relatively high at pH 3-8,but decreased with increasing solution pH from 8 to 12.The presence of coexisting anions such as Cl-,HCO3-and SO42-had negligible influence on phosphate removal by LaMZ.Coexisting Mg2+ had negligible influence on ammonium removal by LaMZ,but coexisting cations such as K+,Na+ and Ca2+ had negative influence on ammonium removal by LaMZ.The main mechanisms for phosphate removal by LaMZ include electrostatic interaction,ligands exchange and Lewis acid-base interaction depending on solution pH.The main mechanism for ammonium removal by LaMZ is cation exchange.关键词
镧改性沸石/磷酸盐/铵/去除Key words
lanthanum-modified zeolite/phosphate/ammonium/removal分类
资源环境引用本文复制引用
李佳,林建伟,詹艳慧,印春生..镧改性沸石对水中磷酸盐和铵的去除性能[J].上海海洋大学学报,2012,21(5):800-808,9.基金项目
国家自然科学基金项目 （）
上海市科学技术委员会项目 （）
上海市教育委员会重点学科建设项目 （）
上海海洋大学博士启动基金项目 （）
长江水环境教育部重点实验室开放课题 （）
