This work focused on the synthesis of iron oxide nanoparticles by the coprecipitation method with three basic solutions, namely, NH₄OH, KOH, and NaOH. The synthesized iron oxides were characterized by various techniques such as XRD, MET, BET, and a SQUID magnetometer. The results showed nanosized particles of 13.2, 9.17, and 8.42 nm and different phases associated to maghemite and maghemite/hematite. The surface areas were 113, 94, and 84 m²/g and the magnetization strength were 58, 61, and 75 emu/g to iron oxides synthesized with NaOH, KOH, and NH₄OH, respectively. The magnetic iron oxides obtained using NaOH were more efficient in the removal of lead and arsenic by adsorption than iron oxides obtained with KOH and NH₄OH. However, the magnetic strength decreases using NaOH and KOH. The highest adsorption capacities attained for lead and arsenic removal were 16.6 and 14 mg/g, respectively, using NaOH-based iron oxides.

中文翻译：

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混合磁赤铁矿/赤铁矿氧化铁纳米颗粒合成用于从水溶液中去除铅和砷

这项工作的重点是通过共沉淀法与三种碱性溶液（即 NH ₄ OH、KOH 和 NaOH）合成氧化铁纳米粒子。通过 XRD、MET、BET 和 SQUID 磁力计等各种技术对合成的氧化铁进行了表征。结果显示 13.2、9.17 和 8.42 nm 的纳米级颗粒以及与磁赤铁矿和磁赤铁矿/赤铁矿相关的不同相。_{对于用NaOH、KOH和NH 4} OH合成的氧化铁，表面积分别为113、94和84m ² /g，磁化强度分别为58、61和75emu/g 。_{使用 NaOH 获得的磁性氧化铁比使用 KOH 和 NH 4}获得的氧化铁更有效地通过吸附去除铅和砷哦。但是，使用 NaOH 和 KOH 会降低磁强度。使用基于 NaOH 的氧化铁，去除铅和砷的最高吸附容量分别为 16.6 和 14 mg/g。