Removal of Congo red dye and Cd(II) and Fe(III) ions from aqueous solution using clay minerals: Equilibrium adsorption studies
This study was performed to assess the removal of dyes and heavy metals from wastewater using locally available natural clays. Modifications of two different local raw clays were carried out by acid activation. The characterization of the raw clay and modified clays were performed by FTIR spectrosco...
| Main Authors: | , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Faculty of Science, University of Peradeniya, Sri Lanka
2021-12-01
|
| Series: | Ceylon Journal of Science |
| Subjects: | |
| Online Access: | https://cjs.sljol.info/articles/7952 |
| Summary: | This study was performed to assess the removal of dyes and heavy metals from wastewater using locally available natural clays. Modifications of two different local raw clays were carried out by acid activation. The characterization of the raw clay and modified clays were performed by FTIR spectroscopy. The effect of contact time, initial concentration of adsorbate, and temperature on the removal of Congo red (CR), Cd(II) and Fe(III) ions from aqueous solutions were investigated using the raw and acid-activated clays. The results showed that optimum adsorption efficiencies of these adsorbates were obtained in 24 h of contact time, for 400 mg L<sup>-1</sup> concentration of adsorbate at the temperature of 303 K. Acid activation of these clays increased the removal efficiency of CR from 80% to 90%, whereas 75% of Cd(II) and Fe(III) ions were adsorbed from aqueous solution by these raw clay minerals. The adsorption process of these systems was studied using Langmuir and Freundlich isotherms. The Langmuir adsorption isotherm gives a better fit for CR, Fe(III) and Cd(II) ions adsorption by the two types of raw clays, whereas CR adsorption by acid-activated clays shows a better fit to Freundlich isotherm. These clays can be used as a cost-effective adsorbent for the removal of pollutants from wastewater. |
|---|---|
| ISSN: | 2513-2814 2513-230X |