Luo Zhen, Zhu Suiyi, Liu Zhongmou, Liu Jiancong, Huo Mingxin, Yang Wu
School of Environment, Northeast Normal University, Changchun 130117, China E-mail:
J Water Health. 2015 Sep;13(3):704-13. doi: 10.2166/wh.2015.210.
Zinc oxide (ZnO) was synthesized and used to investigate the mechanism of phosphate removal from aqueous solution. ZnO particles were characterized by X-ray diffraction, scanning electron microscope and Fourier transform infrared spectroscopy before and after adsorption. Batch experiments were carried out to investigate the kinetics, isotherms, effects of initial pH and co-existing anions. The adsorption process was rapid and equilibrium was almost reached within 150 min. The adsorption kinetics were described well by a pseudo-second-order equation, and the maximum phosphate adsorption capacity was 163.4 mg/g at 298 K and pH ∼6.2±0.1. Thermodynamic analysis indicated the phosphate adsorption onto ZnO was endothermic and spontaneous. The point of zero charge of ZnO was around 8.4 according to the pH-drift method. Phosphate adsorption capacity reduced with the increasing initial solution pH values. The ligand exchange and Lewis acid-base interaction dominated the adsorption process in the lower and the higher pH range, respectively. Nitrate, sulfate and chloride ions had a negligible effect on phosphate removal, while carbonate displayed significant inhibition behavior.
合成了氧化锌（ZnO）并用于研究从水溶液中去除磷酸盐的机制。在吸附前后，通过X射线衍射、扫描电子显微镜和傅里叶变换红外光谱对ZnO颗粒进行了表征。进行了批量实验以研究动力学、等温线、初始pH值和共存阴离子的影响。吸附过程迅速，在150分钟内几乎达到平衡。用伪二级方程很好地描述了吸附动力学，在298 K和pH约为6.2±0.1时，最大磷酸盐吸附容量为163.4 mg/g。热力学分析表明，磷酸盐在ZnO上的吸附是吸热的且是自发的。根据pH漂移法，ZnO的零电荷点约为8.4。随着初始溶液pH值的增加，磷酸盐吸附容量降低。在较低和较高pH范围内，配体交换和路易斯酸碱相互作用分别主导了吸附过程。硝酸根、硫酸根和氯离子对磷酸盐去除的影响可忽略不计，而碳酸根则表现出显著的抑制行为。
