【摘要】 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。更多还原

【Abstract】 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 °C 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, p H, 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.更多还原