Zhang Jiangpo, Xia Qi, Hong Xiaofeng, Chen Jianjun, Liu Daijun
School of Chemical Engineering, Sichuan University, Chengdu 610065, China E-mail:
Water Sci Technol. 2021 Jan;83(1):100-110. doi: 10.2166/wst.2020.567.
In the present study, different ratios of layered double hydroxides (LDHs) were synthesized via co-precipitation method. The synthesized LDHs were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), nitrogen adsorption-desorption analysis, point of zero charges (pH), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Phosphate adsorption performances were estimated by batch adsorption experiments; desorption hysteresis and adsorption mechanism were also investigated. The XRD, SEM and TEM results confirmed the multilayer structure of the synthesized LDHs. The pseudo-second-order kinetic model and the Freundlich model describe the adsorption behavior of LDHs best. The maximum adsorption capacity is 185.86 mg-KHPO/g for MgAl-NO LDH. When the dosage of LDHs was greater than 2 g/L, the phosphorus content in the solution decreased from 30 mg-P/L to 0.077 mg-P/L after adsorption by MgAl-NO LDH. All the results reveal that MgAl-NO LDH is a potential adsorbent for removing phosphate from aqueous solution.
在本研究中，通过共沉淀法合成了不同比例的层状双氢氧化物（LDHs）。采用傅里叶变换红外光谱（FT-IR）、X射线衍射（XRD）、氮吸附-脱附分析、零电荷点（pH）、扫描电子显微镜（SEM）和透射电子显微镜（TEM）对合成的LDHs进行了表征。通过批量吸附实验评估了磷酸盐吸附性能；还研究了解吸滞后和吸附机制。XRD、SEM和TEM结果证实了合成的LDHs的多层结构。准二级动力学模型和Freundlich模型最能描述LDHs的吸附行为。MgAl-NO LDH的最大吸附容量为185.86 mg-KHPO/g。当LDHs的用量大于2 g/L时，MgAl-NO LDH吸附后溶液中的磷含量从30 mg-P/L降至0.077 mg-P/L。所有结果表明，MgAl-NO LDH是从水溶液中去除磷酸盐的潜在吸附剂。
