水滑石焙烧产物对酸性黄49的吸附(英文)

Adsorption of Acid Yellow 49 by Calcined Layered Double Hydroxides

研究了镁铝水滑石的焙烧产物(LDO)对阴离子染料废水酸性黄49(AY49)的吸附性能,分别考察了吸附剂用量、初始pH值、反应温度和竞争离子等因素的影响,探讨了吸附动力学和热力学规律。研究表明:LDO用量为0.02 g,pH=10,T=288 k时,平衡吸附量与去除率分别是738.16 mg·L^(-1)及98.42%,去除AY49的实验数据符合Langmuir吸附等温线,吸附动力学符合准二级动力学模型,反应活化能为71.127 kJ·mol^(-1),表明LDO对AY49的吸附是由AY49与LDO之间的化学反应速率控制而不是两者之间的扩散作用。用XRD表征吸附前后LDO的结构,表明LDO对AY49的吸附是通过"结构记忆效应"来实现的。

The thermodynamics and dynamics for the adsorption of acid yellow 49(AY49) onto layered double oxides(LDO)prepared after calcination by Mg/Al hydrotalcite,the influence of dosage of adsorbent,initial pH value and reaction temperature on the adsorption have been studied.The results indicate that when dosage of AY49,initial pH value,temperature are 0.02 g,10,and288 K,respectively,maximum capacity and percentage removal are 738.16 mg·L^(-1) and 98.42%.The adsorption of AY49 is consistent with Langmuir equations,the adsorption process followed pseudo-second order kinetic model,the active energy value of the adsorption is 71.127 kJ-mol'',which suggests that the process of adsorption of AY49 is controlled by the rate of reaction rather than diffusion.The solid LDO,both fresh and after removal of AY49,was characterized by XRD.The structure of LDO shifts to a layer structure of LDHs after adsorption,indicating that the memory effect of LDO accounts for the effective removal of AY49.