Chromium Adsorption by Three Yeast Strains Isolated from Sediments in Morocco

Abstract

Biosorption is an effective method to remove heavy metals from wastewater. In this work, Biosorption of Cr(VI) has been investigated by live and dead cells of three yeasts species: Cyberlindnera fabianii, Wickerhamomyces anomalus and Candida tropicalis. Sorption experiments were conducted in aqueous solutions at various pH conditions. Cr(VI) adsorption was highly pH dependent and the results indicated that the most effective pH range was found to be between 2 and 4 for the three species. Adsorption isotherms were modeled with the Langmuir and Freundlich equations and isotherm constants were calculated. The adsorption capacity calculated from Langmuir isotherm was 18.9 mg, 28.14 mg and 29.1 mg Cr(VI) g⁻¹ Cr(VI) g⁻¹ for C. fabianii, W. anomalus and C. tropicalis, respectively. The results suggest that the three yeasts could be used as effective adsorbents for the removal of Cr(VI) ions from contaminated sites.

Keywords:

• biosorption
• chromium
• isotherms
• pH
• yeast biomass

Acknowledgments

The authors thankfully acknowledge the financial and scientific support of Microbial Biotechnology Laboratory, Faculty of Sciences and Technology and of Regional Center of Interface (CURI), SMBA University, Fez, Morocco.