Study of the effect of the HDL cations precursors in the removal of arsenic in aqueous solution

MARÍA MARTHA BARROSO QUIROGA; MÒNICA IGLESIAS JUNCÀ; NORA ANDREA MERINO

Fortaleza

Encuentro; 13 Encontro Brasileiro sobre Adsorção; 2020

Layered double hydroxides (LDH) are anionic clays, used as adsorbents, ion exchange material and catalysts. Generally, they present high specific surface areas, alkaline character, high metallic dispersion and high thermal stability. If they contain a transitional element in their structure, it is possible that the solid presents redox properties. LDH were synthesized with the following combinations: MgAl, MgFe, and ZnMgFe, aiming to determinate the effect of cationic nature in the structure and the functionality of the synthesized clay as adsorbents in polluted aqueous effluents. The textural properties were determined by nitrogen adsorption isotherms. Crystalline structure was studied by XRD and the presence of the anions of the interlayer was determined by FTIR spectroscopy. From the results that were obtained from the studies of removal of As(III) and As(V) from aqueous solutions, using the HDL, it is possible to observe that at 24 h the solids had a high percentage of removal. The MgFe solid showed a selectivity to the uptake of As(V), while the MgAl only removed As(III). This selective behavior can be beneficial in studies of arsenic speciation.