Efficient Removal of Antimony(III) in Aqueous Phase by Nano-Fe3O4 Modified High-Iron Red Mud: Study on Its Performance and Mechanism

Yizhe Peng,Shuang Luo,Lin Luo,Yuan Yang,Yaoyu Zhou,Qiming Mao,Kejian Peng,Jian Yang

doi:10.3390/w13060809

Yizhe Peng, Shuang Luo + Show 6 more

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https://doi.org/10.3390/w13060809

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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 specific surface area of 171.63 m2·g−1, measured using the Brunauer-Emmett-Teller measurement. The adsorption process was stable at an ambient pH range, and negligibly limited by temperature the coexisting anions, except for silicate and phosphate, suggesting the high selectivity toward Sb(III). HRM@nFe3O4 retained more than 60% of the initial adsorption efficiency after the fifth adsorption-desorption cycle. The kinetic data fitted by the pseudo-second-order model illustrated the existence of a chemical adsorption process in the adsorption of Sb(III). Further mechanism analysis results indicated that the complexation reaction played a major role in Sb(III) adsorption by HRM@nFe3O4. This HRM@nFe3O4 adsorbent provides an effective method for the removal of Sb(III) in wastewater treatment and is valuable in the reclamation of red mud.

Highlights

Antimony (Sb) is a heavy metal with high toxicity, which may result in harm to humans [1]
high-iron red mud (HRM)@nFe3 O4 retained more than 60% of the initial adsorption efficiency after the fifth adsorptiondesorption cycle
The kinetic data fitted by the pseudo-second-order model illustrated the existence of a chemical adsorption process in the adsorption of Sb(III)

Summary

Introduction

Antimony (Sb) is a heavy metal with high toxicity, which may result in harm to humans [1]. This element is widely found in the environment on account of rock weathering, mining and smelting activities, coal combustion, antimony product release, etc. Sb(III), such as Sb3+ , SbO+ , and Sb(OH)2+ , while neutral species of Sb(OH) and H3 SbO3 are predominant within the pH range from 2.0 to 10.0, and when the pH of the solution is higher than 10.0, only one species of SbO2− exists [3,4]. It is reported that the toxicity of Sb(III) is 10 times higher than Sb(V) [5]. Antimony and antimonic compounds have been categorized as priority pollutants by the United States

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