Bozorgi Mohammad, Mahinroosta Mostafa, Allahverdi Ali
Research Laboratory of Inorganic Chemical Process Technologies, School of Chemical Engineering, University of Science and Technology, Narmak, Tehran, 1684613114, Iran.
Department of Energy, Materials and Energy Research Center, Karaj, Iran.
Sci Rep. 2025 Jan 13;15(1):1856. doi: 10.1038/s41598-025-85964-6.
This study aims to utilize secondary aluminum dross waste to synthesize Fe-Al layered double hydroxide (Fe-Al LDH) for efficient adsorption of arsenic from drinking water. The synthesis process was based on a multi-step hydrometallurgical approach, in which the aluminum content in the waste was first converted to sodium aluminate. This was followed by the transformation into Fe-Al LDH through a series of processes, including gelation, sol formation, simultaneous precipitation, and aging. A suitable crystal structure of the LDH adsorbent was successfully synthesized at a Fe: Al molar ratio of 3, a pH of 7, and an aging time of 12 h. The characterization tests revealed that the synthesized Fe-Al-LDH had an interlayer space of 7.5 Å, a specific surface area of 145 m/g, and a pore volume of 0.57 cm/g. The resulting Fe-Al-LDH was then used to adsorb arsenic from aqueous solutions. The results showed that the amount of arsenic adsorbed by the LDH was 0.144 mg/g at room temperature, the adsorbent dose of 0.5 g/L, pH = 7 and the initial arsenic concentration of 80 µg/L. The Fe-Al LDH reduced the amount of arsenic in the water below the standard value after a period of 40 min. In addition, the results showed that the Fe-Al LDH can stabilize arsenic species in its structure and thus prevent their re-release into the environment.
本研究旨在利用二次铝灰废料合成铁铝层状双氢氧化物（Fe-Al LDH），以高效吸附饮用水中的砷。合成过程基于多步湿法冶金方法，其中废料中的铝含量首先转化为偏铝酸钠。随后通过一系列过程，包括凝胶化、溶胶形成、共沉淀和老化，将其转化为Fe-Al LDH。在铁铝摩尔比为3、pH值为7和老化时间为12小时的条件下，成功合成了具有合适晶体结构的LDH吸附剂。表征测试表明，合成的Fe-Al-LDH的层间距为7.5 Å，比表面积为145 m/g，孔体积为0.57 cm/g。然后将所得的Fe-Al-LDH用于吸附水溶液中的砷。结果表明，在室温、吸附剂剂量为0.5 g/L、pH = 7和初始砷浓度为80 µg/L的条件下，LDH吸附的砷量为0.144 mg/g。经过40分钟后，Fe-Al LDH将水中的砷含量降低到标准值以下。此外，结果表明，Fe-Al LDH可以将砷物种稳定在其结构中，从而防止它们重新释放到环境中。
