用粉煤灰合成载氢氧化铝沸石去除水中的氟化物。
Removal of fluoride from water using aluminum hydroxide-loaded zeolite synthesized from coal fly ash.
机构信息
School of Environmental Science and Engineering, Shanghai Jiao Tong University, No. 800, Dongchuan Road, Shanghai 200240, China.
School of Environmental Science and Engineering, Shanghai Jiao Tong University, No. 800, Dongchuan Road, Shanghai 200240, China.
出版信息
J Hazard Mater. 2022 Jan 5;421:126817. doi: 10.1016/j.jhazmat.2021.126817. Epub 2021 Aug 3.
The removal of fluoride from wastewater is essential as the excess accumulation of fluoride in environment is harmful to the health of humans. In this study, the defluorination of water by aluminum hydroxide-coated zeolite (AHZ), which was synthesized from coal fly ash, was investigated in batches. The Langmuir maximum adsorption capacity of fluoride by AHZ reached 18.12 mg/g. Aluminum hydroxide was shown to be the major component that adsorbed fluoride. More than 92% removal of fluoride was achieved within 2 h, and the fluoride adsorption kinetics were well fitted to a pseudo-second-order model. The point of zero charge (pH) of the AHZ was determined to be 5.52. Fluoride adsorption by AHZ depended greatly on pH, and maximum performance was obtained at pH 5.5-6.5. The AHZ showed good selectivity for the adsorption of fluoride in the presence of chloride, nitrate, sulfate, bicarbonate, and acetate ions, and the fluoride was nearly exhausted at a sufficiently high dose. The release of OH due to fluoride adsorption was confirmed. FTIR and XPS studies further illustrated that the adsorption mechanism of fluoride adsorption on AHZ was ligand exchange with hydroxyl groups and the formation of F-Al bonds.
从废水中去除氟是必要的，因为氟在环境中的过度积累对人类健康有害。在这项研究中，研究了从粉煤灰合成的氢氧化铝包覆沸石（AHZ）对水的除氟作用。AHZ 对氟的朗缪尔最大吸附容量达到 18.12 mg/g。结果表明，氢氧化铝是吸附氟的主要成分。在 2 小时内，氟的去除率超过 92%，氟的吸附动力学很好地符合拟二级模型。确定 AHZ 的零电荷点（pH）为 5.52。AHZ 对氟的吸附强烈依赖于 pH 值，在 pH 值为 5.5-6.5 时，性能最佳。在存在氯离子、硝酸盐、硫酸盐、碳酸氢根和醋酸根离子的情况下，AHZ 对氟的吸附表现出良好的选择性，并且在足够高的剂量下，氟几乎被耗尽。由于氟的吸附而释放出的 OH 得到了证实。FTIR 和 XPS 研究进一步说明了氟在 AHZ 上吸附的吸附机制是与羟基的配体交换和 F-Al 键的形成。
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