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

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@nFe(3)O(4)) was fabricated using the method of co-precipitation to remove Sb(III) from the aqueous phase. The HRM@nFe(3)O(4) at a nFe(3)O(4):HRM mass ratio of 1:1 had optimal adsorbing performance on Sb(III) in water. Compared with others, the synthetic HRM@nFe(3)O(4) sorbent had a superior maximum Sb(III) adsorption capacity of 98.03 mg center dot g(-1), as calculated by the Langmuir model, and a higher specific surface area of 171.63 m(2)center dot 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@nFe(3)O(4) 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@nFe(3)O(4). This HRM@nFe(3)O(4) adsorbent provides an effective method for the removal of Sb(III) in wastewater treatment and is valuable in the reclamation of red mud.