Kinetic Modeling of Arsenic Removal from Water by Ferric Ion Loaded Red Mud

Abstract

A laboratory study was conducted to investigate the ability of ferric ion loaded red mud (FRM) for the removal of arsenic species from water. The adsorbent material was characterized by scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. For an initial arsenic concentration lower than 0.3 mg/L, the FRM with a dosage of 1 g/L was able to reduce As(III) at pH 7 below 10 lg=L, the maximum contaminant level (MCL) of arsenic in drinking water set by the World Health Organization. In the case of As(V) removal, FRM was also particularly effective in reducing the initial arsenic concentration value of 1 mg=L at pH 2, below the MCL requirement of arsenic for drinking water. According to kinetic sorption data, the initial stage of adsorptions of As(III) and As(V) onto FRM were mainly governed by the external diffusion mechanism; however, upon saturation of the external adsorbent surface, the arsenic species were eventually adsorbed by intraparticle diffusion mechanism. The present results are promising for using the very inexpensive FRM as a low-cost material that is effective in remediating drinking waters contaminated with low concentrations of arsenic species. We report here the sorption kinetics and adsorption mechanisms of As(III) and As(V) on the FRM that has not been decsribed previously.

Arsenate and arsenite removal from contaminated water by iron oxides nanoparticles formed inside a bacterial exopolysaccharide

“…The thickness of boundary layer given by the intercept correspond to 6.5 and 11.1 mg/g for 20% and 5% FeEPS. Contrary to what observed by other authors [39,41], the lack of an initial stage related to film diffusion suggested that boundary layer was not limiting in our case. We finally hypothesize that at the same time EPS may exert repulsion with As ions but also facilitate the entrapment into the gel by EPS polysaccharides driven chelation and speeding up the adsorption process, as evidenced by higher adsorption rate during first minutes, in line with what evidenced for positively charged potentially toxic metals [30].…”

“…Several kinetics and thermodynamics models to describe arsenic adsorption processes have been previously reported [37][38][39][40][41].…”

ADSORPTION OF As(III) FROM AQUEOUS SOLUTION ONTO IRON IMPREGNATED USED TEA ACTIVATED CARBON: EQUILIBRIUM, KINETIC AND THERMODYNAMIC STUDY

“…Similarly, Tawabini et al [48] reported maximum percent removal of As(III) at pH 7 and 8 and decrease in adsorption at pH 9 for iron oxide nanoparticles impregnated on carbon nanotubes. Moreover, Kocabas and Yurum [49] observed maximum adsorption of As(III) at pH 7.56 by Ferric ion loaded red mud.…”

Synthesis and Characterization of Pumice-Supported nZVI for Removal of Copper from Waters

“…Adsorption is the most widely used process due to the simplicity of its operation and low implementation costs when compared with other treatment methods [1]. Adsorbent 2 Advances in Materials Science and Engineering substances, most commonly used to remove heavy metals from water, are activated carbon, ion exchange resins, red clay, activated alumina, biomass, and chitosan and carbon nanotubes [7,[13][14][15][16][17][18][19].…”