Efficient adsorbent for the removal of methyl orange and Congo red by calcined Zn-Al layered double hydroxide

Abstract

In this study, calcined layered double hydroxides (ZnAl-cLDH) with Zn/Al molar ratio of 2:1 was prepared via coprecipitation method at constant pH of 9 and calcination at 500 °C. The resultant calcined (ZnAl-cLDH) were applied for the adsorption from Congo red and Methyl orange dye removal from aqueous phase. The adsorption kinetics fit the pseudo-second order kinetic models well and the Langmuir isotherm model exhibited a maximum adsorption capacity of 584.56 mg.g⁻¹ and 451.21 mg.g⁻¹ for Congo red and Methyl orange respectively. The results of adsorption–desorption cycles revealed that ZnAl-cLDH have an excellent potential to be used as an economical adsorbent of wastewater treatment.

Keywords:

• ZnAl-calcined layered double hydroxides
• adsorption
• methyl orange
• Congo red

Acknowledgments

The authors thank and appreciate the Instituto de Catalisis y Petroleoquımica, CSIC, Spain, (Unidad de Apoyo and Laboratorio de Análisis Térmico for the performance of characterization experiments) for the help of sample characterizations.

Disclosure statement

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

Additional information

Funding

This work was supported by the Ministère de l’Enseignement Superieur et de la Recherche Scientifique of Algeria under Research Project PRFU_No. A16N01UN180120190001.