磁性纳米颗粒去除饮用水中铬和镉离子性能的初步研究

Removal of chromium and cadmium in drinking water by magnetic nanoparticles

基于表面修饰的四氧化三铁磁性纳米材料具有高比表面积、高吸附能力及吸附速度快等优点。研究了Fe_3O_4磁性纳米材料的制备及表面修饰条件,及其对饮用水中微量铬和镉离子的吸附、脱附性能。结果表明,在氨水浓度为0.5 mol/L时,采用化学共沉淀法制备的四氧化三铁磁性纳米颗粒产率最大;十二烷基磺酸钠浓度为300 mg/L,与四氧化三铁磁性纳米颗粒配比为2∶3,溶液pH为5.0,表面修饰的四氧化三铁磁性纳米颗粒对重金属镉和铬离子有显著的去除能力,对镉和铬离子的饱和吸附量分别为3.09,2.11 mg/g,在pH为7时,其对镉和铬离子的解析率分别为79%,60.5%。所制备材料的平衡吸附量与平衡质量浓度之间符合Langmuir和Freundlich等温吸附方程。

Based on the advantages of the surface modification of ferroferric oxide（ Fe3O4） magnetic nanomaterials including large surface area,high adsorption capacity and quick adsorption speed,a method for the preparation of Fe3O4 magnetic nanomaterials was established,and their surface modification conditions were investigated. In addition,the adsorption and desorption properties of trace chromium and cadmium ions in drinking water were also studied. The results showed that the yield of Fe3O4 magnetic nanoparticles prepared by chemical coprecipitation method was the highest compared with other preparation methods when the concentration of ammonia was 0. 5 mol/L,the concentration of sodium dodecyl sulfonate was300 mg/L,and the magnetic nano-particles ratio is 2 ∶ 3,the surface modified Fe3O4 magnetic nanoparticles had the ability to remove cadmium and chromium ions with pH = 5,and the saturated adsorption capacity of cadmium and chromium ions was 3. 09 mg/g and 2. 11 mg/g,respectively. At pH = 7,the resolutions of cadmium and chromium ions were 79% and 60. 5%,respectively. The Langmuir and Freundlich isothermal adsorption equation were established between the equilibrium adsorption capacity and the equilibrium mass concentration of the prepared materials.