Adsorption of glutamic acid from aqueous solution with calcined layered double Mg-Fe-CO_3 hydroxide  

Mg-Fe-CLDH对模拟谷氨酸废水的吸附分离(英文)

作　　者：焦飞鹏[1] 帅丽[1] 于金刚[1] 蒋新宇[1] 陈晓青[1] 杜邵龙[1] 

机构地区：[1]中南大学化学化工学院,长沙410083

出　　处：《Transactions of Nonferrous Metals Society of China》2014年第12期3971-3978,共8页中国有色金属学报（英文版）

基　　金：Project(21176263)supported by the National Natural Science Foundation of China

摘　　要：Layered double Mg-Fe-CO3 hydroxide （Mg-Fe-LDH） with a mole ratio of Mg to Fe of 3 was synthesized by coprecipitation method and calcined product Mg-Fe-CLDH was obtained by heating Mg-Fe-LDH at 500 ℃ for 6 h. The as prepared Mg-Fe-LDH and calcined Mg-Fe-CLDH were used for removal of glutamic acid （Glu） from aqueous solution, respectively. Batch studies were carried out to address various experimental parameters such as contact time, pH, initial glutamic acid （Glu） concentration, co-existing anions and temperature. Glu was removed effectively （99.9%） under the optimized experimental conditions with Mg-Fe-CLDH. The adsorption kinetics follows the Ho’s pseudo second-order model. Isotherms for adsorption with Mg-Fe-CLDH at different solution temperatures were well described using the Langmuir model with a good correlation coefficient. The intraparticle diffusion model fitted the data well, which suggests that the intraparticle diffusion is not only the rate-limiting step.采用共沉淀法合成Mg与Fe摩尔比为3:1的层状双金属氢氧化物(Mg-Fe-LDH),然后在500°C下煅烧6 h得到煅烧双金属氢氧化物(Mg-Fe-CLDH)。分析Mg-Fe-CLDH与Mg-Fe-LDH对谷氨酸的吸附性能,研究溶液p H、谷氨酸初始浓度、共存阴离子及温度等因素对吸附效果的影响,并对其吸附过程的动力学和热力学过程进行研究。结果表明:Mg-Fe-CLDH对谷氨酸的吸附效果很好,吸附率在优化条件下达到99.9%;吸附动力学符合准一级动力学方程,平衡吸附等温线很好地符合Langmuir方程。颗粒内扩散模型能很好地描述吸附动力学过程。颗粒内扩散模型拟合结果显示,颗粒内扩散不是唯一的反应速率控制步骤。

关 键 词：calcined layered double hydroxides glutamic acid ADSORPTION 

分 类 号：O647.3[理学—物理化学] X783[理学—化学]