Fabrication of attapulgite/magnetic aminated chitosan composite as efficient and reusable adsorbent for Cr (VI) ions.

ABSTRACT: An efficient composite was constructed based on aminated chitosan (NH₂Cs), attapulgite (ATP) clay and magnetic Fe₃O₄ for adsorptive removal of Cr(VI) ions. The as-fabricated ATP@Fe₃O₄-NH₂Cs composite was characterized by Fourier Transform Infrared Spectroscopy (FTIR), Thermal Gravimetric Analyzer (TGA), Scanning Electron Microscope (SEM), Zeta potential (ZP), Vibrating Sample Magnetometer (VSM), Brunauer-Emmett-Teller method (BET) and X-ray photoelectron spectroscope (XPS). A significant improve in the adsorption profile was established at pH 2 in the order of ATP@Fe₃O₄-NH₂Cs(1:3) > ATP@Fe₃O₄-NH₂Cs(1:1) > ATP@Fe₃O₄-NH₂Cs(3:1) > Fe₃O₄-NH₂Cs > ATP. The maximum removal (%) of Cr(VI) exceeded 94% within a short equilibrium time of 60 min. The adsorption process obeyed the pseudo 2nd order and followed the Langmuir isotherm model with a maximum monolayer adsorption capacity of 294.12 mg/g. In addition, thermodynamics studies elucidated that the adsorption process was spontaneous, randomness and endothermic process. Interestingly, the developed adsorbent retained respectable adsorption properties with acceptable removal efficiency exceeded 58% after ten sequential cycles of reuse. Besides, the results hypothesize that the adsorption process occurs via electrostatic interactions, reduction of Cr(VI) to Cr(III) and ion-exchanging. These findings substantiate that the ATP@Fe₃O₄-NH₂Cs composite could be effectively applied as a reusable adsorbent for removing of Cr(VI) ions from aqueous solutions.

SUBMITTER: Eltaweil AS 

PROVIDER: S-EPMC8368087 | biostudies-literature |

REPOSITORIES: biostudies-literature