锆氧化物改性骨炭的除氟性能及影响因素研究

Study on Defluoridation Performance and Influencing Factors of Zirconium Oxide Modified Bone Charcoal

摘要: 氟是一把“双刃剑”，饮用水是人体摄氟的主要途径。以高温煅烧后的兽骨为原材料，通过锆盐改性制备低成本除氟材料，通过等温吸附实验、pH影响实验、共存离子影响实验以及动态过柱实验，对其除氟机理和影响因素进行了分析。结果表明，在pH = 7，温度为25℃条件下，改性材料对氟离子吸附Langmuir模拟最大吸附容量为6.25 mg/g；由于对改性材料表面电荷属性及数量的影响，pH对改性材料的除氟效果具有直接的影响，弱酸–酸性条件下，材料表现出良好的除氟效果；共存的硫酸根对材料的除氟效果影响较小，而碳酸氢根则影响显著，原因在于高浓度碳酸氢根导致的pH变化及其自身与金属氧化物形成配体而占据吸附点位；动态过柱实验展示了改性材料对实际水体氟离子的出色去除能力，进一步验证了材料的实用性。

Abstract: Fluoride is a “double-edged sword”; drinking water serves as the primary source of fluoride intake for the human body. Low-cost fluoride removal materials were prepared by modifying high-temperature calcined animal bones with zirconium salts. Fluoride removal mechanism and influencing factors of the modified materials were analysed by isothermal adsorption experiments pH effect experiments, coexisting ion effect experiments and dynamic column experiments. The results showed that under the conditions of pH = 7 and temperature of 25˚C, the maximum adsorption capacity of fluoride ions by the modified material was 6.25 mg/g according to the Langmuir model. Due to the influence of the surface charge properties and the amount of modified material, pH had a direct effect on the fluoride removal efficiency of the modified material. Under weakly acidic to acidic conditions, the material showed excellent fluoride removal performance. The co-existing sulphate ions had a minor effect on the fluoride removal performance of the material, while bicarbonate ions had a significant effect. This was because the high concentration of bicarbonate ions caused pH changes and formed ligands with metal oxides, occupying the adsorption sites. The dynamic column experiments demonstrated the excellent fluoride removal performance of the modified material for actual water bodies, further verifying the practicality of the material.