water Article Efficient Removal of Antimony(III) in Aqueous Phase by Nano-Fe3O4 Modified High-Iron Red Mud: Study on Its Performance and Mechanism Yizhe Peng 1,2, Lin Luo 1,*, Shuang Luo 1, Kejian Peng 2, Yaoyu Zhou 1, Qiming Mao 1, Jian Yang 1 and Yuan Yang 1,* 1 International Joint Laboratory of Hunan Agricultural Typical Pollution Restoration and Water Resources Safety Utilization, College of Resources and Environment, Hunan Agricultural University, Changsha 410128, China;
[email protected] (Y.P.);
[email protected] (S.L.);
[email protected] (Y.Z.);
[email protected] (Q.M.);
[email protected] (J.Y.) 2 Hunan Key Laboratory of Water Pollution Control Technology, Hunan Research Academy of Environmental Sciences, Changsha 410004, China;
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[email protected] (Y.Y.); Tel.: +86-0731-8463-8343 (L.L.) Abstract: The resource utilization of excess red mud produced from aluminum production is a current research focus. In this study, novel nano-Fe3O4 modified high-iron red mud material (HRM@nFe3O4) was fabricated using the method of co-precipitation to remove Sb(III) from the aqueous phase. The HRM@nFe3O4 at a nFe3O4:HRM mass ratio of 1:1 had optimal adsorbing performance on Sb(III) in water. Compared with others, the synthetic HRM@nFe3O4 sorbent had a superior maximum Sb(III) adsorption capacity of 98.03 mg·g−1, as calculated by the Langmuir model, and a higher 2 −1 specific surface area of 171.63 m ·g , measured using the Brunauer-Emmett-Teller measurement. The adsorption process was stable at an ambient pH range, and negligibly limited by temperature Citation: Peng, Y.; Luo, L.; Luo, S.; the coexisting anions, except for silicate and phosphate, suggesting the high selectivity toward Sb(III).