(沈阳化工大学 化学工程学院，沈阳 110142)
摘 要: 采用离子交换法制得柠檬酸插层MgAl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、pH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，pH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。
关键字: 水滑石；水处理；吸附；重金属；Zn2+；柠檬酸插层
（School of Chemical Engineering, Shenyang University of Chemical Engineering, Shenyang 110142, China）
Abstract:The citrate intercalated MgAl 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.
Key words: hydrotalcite; water treatment; adsorption; heavy metal; Zn2+; citrate intercalation
