Low-cost magnetic carbons-based rubber seed husks materials for highly efficient removal for reactive black 5 and reactive blue 19 textile dyes from wastewater

ABSTRACT

Suitable and cost-effective magnetic carbons (CA-HP-FeII/FeIII) were prepared from biobased rubber seed hull materials by chemical activation with phosphoric acid and ferric ions. Physical and chemical properties of the materials were investigated using XRD, FT-IR spectroscopy, SEM analysis, N₂ adsorption/desorption, Raman analysis and EDX/EDX-mapping. Magnetic carbons were used to remove reactive black 5 and reactive blue 19 textile dyes in aqueous solution. The pH of the solution, the mass of magnetic carbons and the initial concentration of dyes were investigated. The activated carbon obtained has a surface area of 110 m².g⁻¹ with an amorphous structure. A maximum removal efficiency of 76.27% for reactive black dye 5 and 94.44% for reactive blue dye 19 was achieved, at optimum pH 2. Kinetic studies showed that non-linear Elovich’s model accurately describes the adsorption mechanism, which assumes an energetically heterogeneous magnetic carbon surface. The two-parameter non-linear models for the adsorption isotherms revealed that the adsorption of reactive black 5 and reactive blue 19 on CA-HP-FeII/FeIII satisfied the Temkin isotherm, demonstrating the exothermic nature of the adsorption process. The three-parameter adsorption isotherm reveals that the magnetic carbons have a heterogeneous surface with energetically diverse adsorption sites. Magnetic carbons were found to be attractive and suitable for the purification of these dyes.

KEYWORDS:

• Activated carbon
• rubber seed
• adsorption
• reactive blue 19
• reactive black 5
• non-linear method

Acknowledgments

The authors acknowledge the technical assistance provided by the researchers of the Materials and Process Engineering Team/RU-NOGEE at the Department of Chemistry, Faculty of Science, University of Dschang, Cameroon and also grateful for the “Allocation spéciale pour la modernisation de la recherche universitaire” from the Ministry of Higher Education (Cameroon).

Disclosure statement

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

Data availability statement

The experiment provided the data for this study article. A small number of the statistics used to back up the study’s findings are provided in the article, while others can be requested from the corresponding author.