Mg-La-Fe/沸石复合材料的制备及其处理低浓度含磷废水的性能

以沸石为载体，选用镁、镧和铁为改性剂，采用水热法制备了一种新型高效且易于磁性分离回用的载镧磁性沸石吸附剂（MLFZ）.等温吸附和动力学研究结果表明，其吸附行为符合Langmuir等温模型和准二级动力学模型，MLFZ饱和吸附量为13.46 mg·g^-1; MLFZ在pH为3～9范围内均表现出良好的吸附性能，共存离子条件下对磷酸根具有特异吸附能力，通过磁性吸附重复使用5次后，MLFZ对磷酸盐去除率维持在90%左右，突显了其易于回收再利用的优点；FTIR、 XPS和Zeta电位表征显示，表面沉积、静电吸附作用和镧与磷酸盐通过配体交换形成内层络合物在吸附过程中为主要作用.将MLFZ用于处理自然池塘污水，结果显示磷酸盐浓度由0.86 mg·L^-1降低到0.013 mg·L^-1,表明该吸附剂具有良好的实际应用前景.

Development of Zeolite Loaded Mg-La-Fe Ternary (hydr) oxides for Treatment of Low Concentration Phosphate Wastewater

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^-1 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^-1 to 0.013 mg·L^-1), indicating that the MLFZ was an ideal material for phosphate management and treatment.