焙烧型镁铝双金属氢氧化物对水中苯甲酸的吸附行为  

Adsorption behavior of benzoic acid in water with calcined Mg/Al layered double hydroxides

作　　者：刘玲[1] 何小丽[1] 

机构地区：[1]肇庆学院化学化工学院,广东肇庆526061

出　　处：《日用化学工业》2015年第3期127-131,160,共6页China Surfactant Detergent & Cosmetics

基　　金：广东省教育厅科技创新项目(2013KJCX0194)

摘　　要：采用共沉淀法制备镁铝双金属氢氧化物(LDHs)功能材料,并在500℃焙烧得到改性的层状氢氧化镁铝(LDO),利用XRD和FTIR对改性前后的产物结构进行表征。以LDO为吸附剂、水中苯甲酸为研究对象,具体考察了吸附剂的投加量、p H、吸附平衡时间及恒温水浴振荡温度等实验条件对苯甲酸脱除效果的影响。结果表明,在25 m L质量浓度为0.6 g/L的苯甲酸溶液中,吸附剂投加量0.8 g,p H=8.0,吸附60 min,(25±0.5)℃的条件下脱除效果较佳,脱除率可达到77.9%。此外,吸附反应较符合Langmuir吸附等温模型,该吸附是一个自发放热反应,吸附热为-17.01 k J/mol。The functional material Mg/Al layered double hydroxides（ LDHs） was prepared by co- precipitation method,and the material was calcined at 500 ℃ to obtain modified Mg/Al layered double hydroxides（ LDO）.Structure of the product before and after modification was characterized by XRD and FTIR. With LDO as adsorbent,adsorption of benzoic acid in water was examined. Effect of experimental conditions such as dosage of adsorbent,p H,adsorption equilibrium time and oscillation temperature of thermostatic waterbath on effectiveness of removal of benzoic acid in water were specifically investigated. Results indicated that the better condition appears as the dosage of adsorbent,pH,adsorption time and temperature are 0. 8g,8. 0,60 min and（ 25 ± 0. 5） ℃ respectively in 25 mL 0. 6g /L benzoic acid solution. Under such conditions,the removal ratio of benzoic acid achieves 77. 9%. In addition,the adsorption reaction conforms to the Langmuir adsorption isotherm models,and the adsorption is an exothermic reaction. Adsorption heat is- 17. 01 kJ/mol.

关 键 词：镁铝双金属氢氧化物 吸附 苯甲酸 脱除率 热力学 

分 类 号：TQ424.2[化学工程]