Synthesis and characterization of pure and Al-substituted akaganeites and evaluation of their performance to adsorb As(V)

TUFO, ANA E.; LARRALDE, ANA L.; VILLARROEL-ROCHA, JHONNY; SAPAG, KARIM; SILEO, ELSA E.

Journal of Environmental Chemical Engineering

Elsevier

Lugar: Amsterdam; Año: 2019 vol. 6 p. 7044 - 7053

2213-3437

Several samples of pure and Al-substituted akaganeites with somatoid (SOM), rod- like (ROD) and nano-crystals (NANO) morphologies were synthesized and fully characterized. The specific surface areas and the total pore volume varied in the trend SOMNANO. This parameter remained unchanged with Al-substitution in SOM-akaganeite but it increased in ROD-akaganeites. The performance on the As(V) adsorption properties was also evaluated. The amount of As(V) adsorbed by NANO (mmol g-1) at saturation (Γmax) was three times larger than the correspondent to SOM. The pure and Al-SOM exhibited the highest Γmax (mmol m-2) indicating a highest surface reactivity towards As-adsorption. Taking into account these marked differences in the As(V) adsorption capacity of the various akaganeites, and their similarities in the structure, chemical composition and surface charge, it can be concluded that the textural characteristics are the main determinant of the adsorption properties.