Removal efficiency of As(III) from aqueous solutions using natural and Fe(III) modified bentonites

ABSTRACT

Contamination of water with arsenic is a major global health problem. The use of adsorbent materials for the removal of As from aqueous systems is a plausible solution to this problem. In this work, the use of commercial bentonites (purified and modified with iron (III)) for the removal of As from water was studied. The samples were characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier Transformed Infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and nitrogen adsorption/desorption isotherms to determine their physicochemical properties. The arsenic removal capacities of adsorbent materials were studied from 1 mg/L solutions of As (III) using the colorimetric technique of molybdenum blue. High adsorption capacity (0.33 mg/g) of As (III) was obtained in aqueous systems after 1 h of treatment with unmodified bentonite. The incorporation of iron improved the removal performance in short times. The obtained results could be the starting point for the development of a low-cost filtration system that contributes to solve the problem of arsenic in water.

GRAPHICAL ABSTRACT

KEYWORDS:

• Adsorption
• arsenic
• bentonite
• remediation
• water

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The data that support the findings of this study are available from the corresponding author, Leonardo Cano, upon reasonable request.

Additional information

Funding

Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de Mar del Plata (UNMdP), – Universidad Nacional de San Luis (UNSL), and Agencia Nacional de Promoción Científica y Tecnológica (ANPCyT) [Grant Number PICT 2018-1215] are acknowledged for the financial support this work.