磁性镧基吸附剂的制备及其除磷效能研究

Fabrication of Magnetic Lanthanum-Based Adsorbent and Its Phosphate Removal Performance

摘要: 输配水过程中，微生物的再生长往往会使水质恶化。相对于易产生有毒有害副产物的消毒法，本研究采用了更为绿色安全的营养源控制法，通过控制水中的磷源来达到实现水质生物稳定性的目的。首先，采用简单的浸渍–共沉淀法制备得到了磁性镧基吸附剂LFP，并探究了其除磷效果、影响因素及除磷机制，该吸附剂具有较高磷吸附容量(41.61 mgP·g⁻¹)的同时，还具有较高的磷选择性和pH适应性，在pH 3~12均具有较高的磷吸附容量(22.88 mgP·g⁻¹以上)。吸附过程符合Langmuir等温吸附模型及准二级动力学模型，吸附机制包含静电吸引及配体交换作用，此外，吸附剂具有较强的磁性(16.28 emu·g⁻¹)，易实现磁分离，使其向实际应用更进一步。

Abstract: The re-growth of microorganisms during water transmission and distribution often deteriorates water quality. Compared with the disinfection method, which is prone to produce toxic and harmful by-products, this study adopted a greener and safer nutrient source control method to achieve water quality biostability by controlling the phosphorus source in water. Firstly, the magnetic lanthanide-based adsorbent LFP was prepared by a simple impregnation-co-precipitation method, and its phosphorus removal effect, influencing factors and phosphorus removal mechanism were investigated. The adsorbent had a high phosphorus adsorption capacity (41.61 mgP·g⁻¹) and also a high phosphorus selectivity and pH adaptability, and it had high phosphorus adsorption capacity (22.88 mgP·g⁻¹) in the range of pH 3~12. The adsorption process was consistent with the Langmuir isothermal adsorption model and the quasi-secondary kinetic model, and the adsorption mechanism included electrostatic attraction and ligand exchange. In addition, the adsorbent possessed strong magnetism (16.28 emu·g⁻¹), which was easy to realize the magnetic separation, and thus it was a step forward to the practical application.