NaZH复合材料的制备及其对Mn2+的吸附性能

制备3% NaCl改性沸石负载羟基磷灰石复合材料(NaZH)，采用摇瓶试验研究pH、材料投加量、Mn2+初始浓度和反应时间对NaZH吸附Mn2+效果的影响，并通过吸附动力学模型和吸附等温模型初步分析吸附机理。此外，应用SEM-EDS、BET、FTIR和XPS等表征手段进一步探究NaZH的材料性质及反应机理。结果表明，Mn2+溶液pH=7、初始浓度5 mg/L、NaZH投加量2 g/L和反应时间240 min为最佳吸附条件，此时Mn2+去除率和吸附量分别为99.25%和2.58 mg/g。吸附过程符合Freundlich模型和准二级动力学模型，为多层化学吸附。表征结果显示，NaZH是羟基磷灰石包裹在沸石表面的复合材料，粗糙多孔，官能团丰富。NaZH主要以溶解-沉淀、离子交换和表面络合三种形式吸附Mn2+。

Preparation of NaZH Composite and Its Adsorption Property on Mn2+

3% NaCl-modified zeolite loaded hydroxyapatite (NaZH) material was prepared. The effects of pH value, material dosage, initial concentration of Mn2+ and reaction time on the adsorption of Mn2+ by NaZH were studied by shake-flask experiment. The adsorption mechanism was preliminically analyzed by adsorption kinetics model and adsorption isothermal model. In addition, SEM-EDS, BET, FTIR and XPS were used to further investigate the material properties and reaction mechanism of NaZH. The results show that the removal rate and adsorption capacity of Mn2+ is 99.25% and 2.58 mg/g respectively under the optimal adsorption conditions including pH=7, initial concentration of 5 mg/L, NaZH dosage of 2 g/L and reaction time of 240 min. The adsorption process is a multilayer chemisorption which conforms to the Freundlich model and quasi-second-order kinetic model. The characterization results show that NaZH is a composite of hydroxyapatite coated zeolite with rough surface and abundant functional groups. Furthermore, the adsorption of Mn2+ is mainly in three forms: solution-precipitation, ion exchange and surface complexation.