Joint Research Center for Protective Infrastructure Technology and Environmental Green Bioprocess, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Tianjin 300384, PR China E-mail:
TG Hilyte Environment Technology (Beijing) Co., Ltd, Beijing 100000, PR China.
Water Sci Technol. 2022 Aug;86(4):643-655. doi: 10.2166/wst.2022.239.
Fluoride is an essential micronutrient for humans. Nonetheless, when the amount of fluoride ion is greater than required, it will cause skeletal fluorosis and dental fluorosis to threaten human health. In this paper, a series of sodium alginate (SA)-based foam materials are prepared by freeze-drying technique and anchored with the nano-activated alumina (nAlO) in the SA to obtain a novel adsorbent of SA-nAlO foam used for fluoride ions removal. The SA-nAlO foam morphology was further explored and confirmed that nAlO existed stably in the SA. The adsorption results showed that the maximal fluoride ion adsorption capacity was 5.09 mg/g with 20 mg/L fluorine solutions at a pH of 3. The adsorption isotherm fitted adequately to the Langmuir isotherm model, which demonstrated that the adsorption process is closer to monolayer adsorption. The adsorption kinetics behavior of SA-nAlO foam was described by a pseudo-second-order model, and the adsorption process occurred by chemisorption. Adsorption thermodynamics analysis emphasized that the adsorption process was spontaneous and endothermic. The main mechanism of the foam is ion exchange. The SA-nAlO foam exhibited excellent regeneration performance and stability after three cycles.
氟是人体必需的微量元素。然而，当氟离子的含量超过所需时，它会导致氟骨症和氟斑牙威胁人类健康。在本文中，通过冷冻干燥技术制备了一系列海藻酸钠（SA）基泡沫材料，并将纳米活性氧化铝（nAlO）锚定在 SA 中，得到了一种新型的用于去除氟离子的 SA-nAlO 泡沫吸附剂。进一步探索了 SA-nAlO 泡沫的形态，并证实 nAlO 稳定存在于 SA 中。吸附结果表明，在 pH 值为 3 的 20 mg/L 氟溶液中，最大氟离子吸附容量为 5.09 mg/g。吸附等温线很好地符合朗缪尔等温线模型，表明吸附过程更接近单层吸附。SA-nAlO 泡沫的吸附动力学行为由拟二级模型描述，吸附过程是通过化学吸附发生的。吸附热力学分析强调，吸附过程是自发和吸热的。泡沫的主要机制是离子交换。SA-nAlO 泡沫在经过三次循环后表现出优异的再生性能和稳定性。
