氢氧化镧交联壳聚糖微球的微流控制备及其除磷性能

基于微流控技术制备了氢氧化镧La(OH)₃]交联壳聚糖（CS）微球（La-CS-M），并对其组成和结构进行表征，探究了微球吸附去除水中磷酸盐的性能和机理。结果表明，La-CS-M成功负载了La（OH）₃，与传统滴落法制备的氢氧化镧交联壳聚糖球（La-CS）相比，其表面和内部具有疏松多孔结构，其体积平均粒径为415.8 μm，孔隙率为89.22%，平均孔径为960.0 nm，pH_pzc约为6.5。La-CS-M在宽pH范围内（3.0~10.0）均保持较高吸附量，\mathrm{C}{\mathrm{O}}_{\mathrm{3}}^{\mathrm{2}-}对La-CS-M吸附性能影响较Cl^-、\mathrm{N}{\mathrm{O}}_{\mathrm{3}}^{-}、\mathrm{S}{\mathrm{O}}_{\mathrm{4}}^{\mathrm{2}-}以及腐殖酸（HA）明显。吸附动力学数据符合准二级动力学模型，等温吸附数据符合Langmuir模型且在pH=6.0时最大吸附量为56.48 mg/g。结合XPS表征和吸附数据推测La-CS-M的吸附机理涉及静电吸附和形成内层配合物（通过配位交换或Lewis酸碱作用）。吸附磷酸盐后La-CS-M可通过2.5 mol/L NaOH溶液实现脱附，具有良好的再生性和吸附稳定性。

Microfludically-generated lanthanum hydroxide cross-linked chitosan microspheres for phosphate removal

Lanthanum hydroxide La(OH)₃] cross-linked chitosan (CS) microspheres (La-CS-M) were prepared based on microfluidic technology. The compositions and structures of La-CS-M were characterized by various means. The performance and mechanism of its adsorption and removal of phosphate in water were explored. The results showed that La(OH)₃ was successfully loaded within La-CS-M. Compared with the cross-linked chitosan spheres (La-CS) prepared by traditional dropping method, the surface and interior of La-CS-M were porous with an volumetric mean particle size of 415.8 μm, porosity of 89.22%, average pore size of 960.0 nm, and pH_pzc of about 6.5. La-CS-M maintained a high adsorption capacity in a wide pH range from 3.0 to 10.0, and the presence of \mathrm{C}{\mathrm{O}}_{\mathrm{3}}^{\mathrm{2}-} had a more negative effect on phosphate adsorption compared to Cl^-, \mathrm{N}{\mathrm{O}}_{\mathrm{3}}^{-}, \mathrm{S}{\mathrm{O}}_{\mathrm{4}}^{\mathrm{2}-} and humic acid (HA). The adsorption kinetic data and isotherm results were well fitted with pseudo-second-order model and Langmuir model, achieving a maximum adsorption capacity of 56.48 mg/g at pH 6.0. Combined with XPS characterization and adsorption data, it could be deducted that the adsorption mechanism of La-CS-M involved electrostatic adsorption and formation of inner sphere complex (through coordination exchange or Lewis acid-base interaction). After phosphate adsorption, La-CS-M could be desorbed by 2.5 mol/L NaOH solution, exhibiting good reproducibility and adsorption stability.