柠檬酸插层MgAl水滑石对水溶液中Zn^(2+)的吸附性能  

Adsorption performance of citrate intercalated Mg Al layered double hydroxides on Zn^(2+) in aqueous solution

作　　者：申延明[1] 张僖[1] 赵晓蕾[1] 刘东斌[1] 樊丽辉[1] 李士凤[1] 

机构地区：[1]沈阳化工大学化学工程学院,沈阳110142

出　　处：《中国有色金属学报》2015年第8期2300-2308,共9页The Chinese Journal of Nonferrous Metals

基　　金：辽宁省教育厅科技项目(L2014169)

摘　　要：采用离子交换法制得柠檬酸插层Mg Al水滑石吸附剂,对吸附剂进行XRD、IR、SEM和BET表征,考察制备的吸附剂对溶液中Zn2+的吸附能力,探讨吸附剂投加量、Zn2+溶液浓度、p H以及吸附温度对Zn2+吸附率的影响,并进行动力学和热力学特征的研究。结果表明:吸附条件对Zn2+的吸附能力影响较大,适宜的水滑石投加量为2~3 g/L,p H以弱酸性为宜,对于Zn2+浓度不超过80 mg/L的溶液,室温下Zn2+吸附率在60%以上,而高温有利于提高Zn2+吸附率。吸附过程符合二级动力学模型,吸附等温曲线可用R-P模型来描述。吸附过程能够自发进行,为吸热过程。The citrate intercalated MgA1 layered double hydroxides adsorbent was prepared by anion-exchange method. The absorbents prepared were characterized by XRD, IR, SEM, BET and used to adsorb Zn2＋ from aqueous solutions. The effects of adsorbent dosage, initial Zn2＋ concentration, pH, adsorption temperature on the Zn2＋ adsorption rate were investigated. The thermodynamics and kinetics characters were discussed. The results show that the adsorption capacity for Zn2＋ is affected by adsorption conditions. The suitable adsorbent dosage is 2-3 g/L, and pH is weak acidity. Under the above conditions, Zn2＋ adsorption efficiency is over 60% at the Zn2＋ concentration less than 80 mg/L, and high temperature is benefit to improve Zn2＋ adsorption rate. Adsorption process conforms to the secondary kinetics model, and the isothermal adsorption curve can be described by R-P model. The adsorption process is spontaneous and endothermic.

关 键 词：水滑石 水处理 吸附 重金属 Zn2+ 柠檬酸插层 

分 类 号：X703.5[环境科学与工程—环境工程]