State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
J Hazard Mater. 2010 Jan 15;173(1-3):102-9. doi: 10.1016/j.jhazmat.2009.08.054. Epub 2009 Aug 20.
A novel magnetic nanosized adsorbent using hydrous aluminum oxide embedded with Fe(3)O(4) nanoparticle (Fe(3)O(4)@Al(OH)(3) NPs), was prepared and applied to remove excessive fluoride from aqueous solution. This adsorbent combines the advantages of magnetic nanoparticle and hydrous aluminum oxide floc with magnetic separability and high affinity toward fluoride, which provides distinctive merits including easy preparation, high adsorption capacity, easy isolation from sample solutions by the application of an external magnetic field. The adsorption capacity calculated by Langmuir equation was 88.48 mg g(-1) at pH 6.5. Main factors affecting the removal of fluoride, such as solution pH, temperature, adsorption time, initial fluoride concentration and co-existing anions were investigated. The adsorption capacity increased with temperature and the kinetics followed a pseudo-second-order rate equation. The enthalpy change (Delta H(0)) and entropy change (DeltaS(0)) was 6.836 kJ mol(-1) and 41.65 J mol(-1)K(-1), which substantiates the endothermic and spontaneous nature of the fluoride adsorption process. Furthermore, the residual concentration of fluoride using Fe(3)O(4)@Al(OH)(3) NPs as adsorbent could reach 0.3 mg L(-1) with an initial concentration of 20 mg L(-1), which met the standard of World Health Organization (WHO) norms for drinking water quality. All of the results suggested that the Fe(3)O(4)@Al(OH)(3) NPs with strong and specific affinity to fluoride could be excellent adsorbents for fluoride contaminated water treatment.
一种新型的磁性纳米吸附剂，采用水合氧化铝嵌入 Fe(3)O(4)纳米粒子（Fe(3)O(4)@Al(OH)(3) NPs）制成，用于从水溶液中去除过量的氟化物。该吸附剂结合了磁性纳米粒子和水合氧化铝絮体的优点，具有磁性分离和对氟化物的高亲和力，具有易于制备、高吸附容量、易于通过施加外磁场从样品溶液中分离等显著优点。在 pH 6.5 时，通过 Langmuir 方程计算的吸附容量为 88.48 mg g(-1)。研究了影响氟化物去除的主要因素，如溶液 pH、温度、吸附时间、初始氟化物浓度和共存阴离子。吸附容量随温度升高而增加，动力学遵循拟二级速率方程。焓变（Delta H(0)）和熵变（DeltaS(0)）分别为 6.836 kJ mol(-1)和 41.65 J mol(-1)K(-1)，证实了氟化物吸附过程是吸热和自发的。此外，使用 Fe(3)O(4)@Al(OH)(3) NPs 作为吸附剂，初始浓度为 20 mg L(-1)时，氟化物的残留浓度可达到 0.3 mg L(-1)，符合世界卫生组织（WHO）饮用水质量标准。所有结果表明，Fe(3)O(4)@Al(OH)(3) NPs 对氟化物具有很强的特异性亲和力，可作为氟化物污染水的优良吸附剂。
