Valorization of El Haria clay in the removal of arsenic from aqueous solution

Abstract

The present work aims to focus on the contribution of El Haria clay aged the Maastrichtien-Paleocene, which level largely in Gafsa basin (Southern Tunisian). Clay of the El Haria Formation was considered a better and low-cost adsorbent for As(III) removal from aqueous solution. Mineralogical analysis showed that this material is composed of 80% smectite and 20% illite. The cation exchange capacity reaches 120 meq/100 g that especially confirms the presence of montmorillonite. Textural analyses reveal a porosity of 43% and a specific surface reaching 158 m²/g. In this study, a Batch mode was used for As(III) adsorption on El Haria natural clay. We have varied several parameters such as pH and temperature. At 25°C, the As(III) adsorption showed that the ions of arsenic had more mobility in pH ranging from 3 to 9 and the maximum adsorption capacity reaches 75.4 mg/g. Mineralogical characteristics confer to the El Haria clays a better adsorption capacity of heavy metals.

Keywords:

• Valorization
• El Haria smectite
• Mineralogy
• Arsenic removal

Acknowledgments

Thanks are extended to Mr Nidhal Baccar, Technician in the Biotechnology Research Center of Sfax for facilitating the analysis of samples using Atomic Absorption Spectrometer (AAS), FTIR analysis. Authors would like to thank the reviewers for helpful comments and suggestions.