The effective Ni(II) removal of red mud modified chitosan from aqueous solution

Abstract

To remove Ni(II) ions from an aqueous solution, researchers used red mud modi ed by chitosan (RM/CS) material as a new adsorbent. According to the ndings, the surface area of red mud is nearly doubled after being treated with chitosan, from 68.6 m 2 /g to 105.7 m 2 /g. The effects of pH solution, contact time, and material dosage on the Ni(II) uptake were examined. In comparison with the pseudo-rst-order and pseudo-second-order models, the intra-diffusion model was the most suitable kinetic model for the Ni(II) removal. Besides, the three-parameter Sips model was used to predict the Ni(II) adsorption of RM/CS from aqueous solution. Furthermore, the Langmuir maximum Ni(II) uptake capacity of this material was 31.66 mg/g at 323K, which was higher than red mud and several other natural materials. Notably, thermodynamic investigations demonstrated that Ni(II) adsorption on RM/CS is both exothermic and physic.

Analysis of Alkali in Bayer Red Mud: Content and Occurrence State in Different Structures

“…As a major producer of alumina, China produced more than 120 million tons of red mud in 2022, with a cumulative stockpile of 1.7 billion tons. Red mud created with the Bayer process is used as an industrial by-product for other applications, such as building materials [1][2][3][4][5][6] and environmental [7][8][9][10], chemical [2,[11][12][13][14][15], agronomic [16][17][18][19], metallurgical [20][21][22] processes, and so on. Currently, building materials consume reused red mud the most.…”