Yin Xue-Jie, Song Xiao-Bao, Ding Chen-Man, Feng Yan-Fang, Yang Bei, He Shi-Ying, Xue Li-Hong
Institute of Agricultural Resources and Environment, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.
School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013, China.
Huan Jing Ke Xue. 2022 Jul 8;43(7):3699-3707. doi: 10.13227/j.hjkx.202110202.
A novel Mg-La-Fe ternary (hydr)oxide magnetic zeolite adsorbent (MLFZ) was prepared using the hydrothermal method and employed for effective phosphate removal in this study. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) indicated that the MLFZ presented an amorphous surface with Mg, Fe, and La dispersed on the surface of the zeolite. The isothermal adsorption and kinetics results showed that the adsorption behavior of the MLFZ was consistent with that of the Langmuir isothermal model and quasi-second-order kinetics model. A relatively fast adsorption of phosphate with a short equilibrium time of 30 min was observed in the kinetics experiment, and the maximum adsorption capacity of the MLFZ was 13.46 mg·g in the equilibrium adsorption isotherm study. The MLFZ showed effective adsorption performance over a wide pH range from 3.0 to 9.0. Moreover, the coexisting ions had an insignificant effect on phosphate adsorption. The MLFZ could easily be recovered using a magnet. After five adsorption-desorption cycles, the phosphate removal efficiency was maintained at approximately 90%. The FTIR, XPS, and Zeta potential analysis confirmed that the adsorption mechanisms were attributed to the surface deposition, electrostatic adsorption, and the inner complex formation by ligand exchange between lanthanum and phosphate. Furthermore, the MLFZ demonstrated high efficiency in scavenging phosphate from a natural pond (phosphate concentration decreased from 0.86 mg·L to 0.013 mg·L), indicating that the MLFZ was an ideal material for phosphate management and treatment.
本研究采用水热法制备了一种新型的镁 - 镧 - 铁三元（氢）氧化物磁性沸石吸附剂（MLFZ），并将其用于高效去除磷酸盐。扫描电子显微镜（SEM）和X射线衍射（XRD）表明，MLFZ呈现出无定形表面，镁、铁和镧分散在沸石表面。等温吸附和动力学结果表明，MLFZ的吸附行为符合朗缪尔等温模型和准二级动力学模型。在动力学实验中观察到磷酸盐吸附相对较快，平衡时间为30分钟，在平衡吸附等温线研究中，MLFZ的最大吸附容量为13.46 mg·g。MLFZ在3.0至9.0的宽pH范围内表现出有效的吸附性能。此外，共存离子对磷酸盐吸附的影响不显著。MLFZ可以很容易地用磁铁回收。经过五个吸附 - 解吸循环后，磷酸盐去除效率保持在约90%。傅里叶变换红外光谱（FTIR）、X射线光电子能谱（XPS）和zeta电位分析证实，吸附机制归因于表面沉积、静电吸附以及镧与磷酸盐之间通过配体交换形成的内层配合物。此外，MLFZ在从天然池塘中去除磷酸盐方面表现出高效率（磷酸盐浓度从0.86 mg·L降至0.013 mg·L），表明MLFZ是用于磷酸盐管理和处理的理想材料。
