Adsorptive Removal of Yellow Dye Using Natural and Magnetic Bentonite: Isotherm, Thermodynamic and Mechanistic Insights

Leyla Durmazuçar; Selen Yakar; Unsal Açıkel

doi:10.17776/csj.1931930

Adsorptive Removal of Yellow Dye Using Natural and Magnetic Bentonite: Isotherm, Thermodynamic and Mechanistic Insights

Abstract

The adsorption performance of natural bentonite (B) and magnetically modified bentonite (MB) for the removal of an anionic yellow dye (YD) from aqueous solution was comparatively investigated using a batch adsorption system. Magnetic bentonite was synthesized via the co-precipitation of Fe²⁺ and Fe³⁺ ions onto the bentonite surface, and the structural modifications were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The characterization results confirmed the successful incorporation of Fe₃O₄ onto the bentonite surface while preserving the fundamental layered structure of bentonite and creating additional adsorption-active surface features. The effects of solution pH, adsorbent dosage, initial dye concentration, and temperature were systematically investigated to determine the optimum adsorption conditions. Adsorption equilibrium was evaluated using the Langmuir, Freundlich, Dubinin–Radushkevich (D–R), and Temkin isotherm models. Among the investigated models, the Langmuir isotherm provided the best fit to the experimental data, with correlation coefficients ranging from 0.989 to 0.998 for natural bentonite and 0.985 to 0.999 for magnetic bentonite, indicating predominantly monolayer adsorption. The maximum Langmuir adsorption capacities obtained at an adsorbent dosage of 0.1 g were 333.3 mg g⁻¹ for natural bentonite and 312.5 mg g⁻¹ for magnetic bentonite. The calculated separation factor (R_L) values (0 < R_L < 1) confirmed that adsorption was favorable under all investigated conditions. Thermodynamic analysis demonstrated that the adsorption process was spontaneous. (ΔG < 0) and exothermic (ΔH < 0) for both adsorbents. Magnetic modification altered the surface characteristics of bentonite, promoted favorable adsorption behavior under different operating conditions, and enabled rapid magnetic separation after adsorption. Overall, both natural and magnetic bentonites exhibited effective adsorption performance, indicating their potential as economical and environmentally friendly adsorbents for the treatment of dye-contaminated wastewater.

Keywords

Adsorption isotherms, Bentonite, Magnetic bentonite, Thermodynamics, Wastewater treatment

Supporting Institution

Sivas Cumhuriyet University, Faculty of Engineering, Department of Chemical Engineering

Project Number

BAP/M858

Ethical Statement

This study does not involve human participants or animals. Therefore, ethical approval was not required.

Thanks

The authors acknowledge Sivas Cumhuriyet University for providing laboratory facilities.

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Details

Primary Language

English

Subjects

Chemical Engineering (Other)

Journal Section

Research Article

Authors

Leyla Durmazuçar ^*
0009-0001-4475-562X
Türkiye

Selen Yakar
0009-0008-8577-4123
Türkiye

Unsal Açıkel
0000-0003-4969-8502
Türkiye

Publication Date

August 31, 2026

Submission Date

April 20, 2026

Acceptance Date

July 29, 2026

Published in Issue

Year 2026 Volume: 47 Number: 4

DOI

https://doi.org/10.17776/csj.1931930

IZ

https://izlik.org/JA56US32YL

APA

Durmazuçar, L., Yakar, S., & Açıkel, U. (2026). Adsorptive Removal of Yellow Dye Using Natural and Magnetic Bentonite: Isotherm, Thermodynamic and Mechanistic Insights. Cumhuriyet Science Journal, 47(4), 714-728. https://doi.org/10.17776/csj.1931930

AMA

1.Durmazuçar L, Yakar S, Açıkel U. Adsorptive Removal of Yellow Dye Using Natural and Magnetic Bentonite: Isotherm, Thermodynamic and Mechanistic Insights. CSJ. 2026;47(4):714-728. doi:10.17776/csj.1931930

Chicago

Durmazuçar, Leyla, Selen Yakar, and Unsal Açıkel. 2026. “Adsorptive Removal of Yellow Dye Using Natural and Magnetic Bentonite: Isotherm, Thermodynamic and Mechanistic Insights”. Cumhuriyet Science Journal 47 (4): 714-28. https://doi.org/10.17776/csj.1931930.

EndNote

Durmazuçar L, Yakar S, Açıkel U (August 1, 2026) Adsorptive Removal of Yellow Dye Using Natural and Magnetic Bentonite: Isotherm, Thermodynamic and Mechanistic Insights. Cumhuriyet Science Journal 47 4 714–728.

IEEE

[1]L. Durmazuçar, S. Yakar, and U. Açıkel, “Adsorptive Removal of Yellow Dye Using Natural and Magnetic Bentonite: Isotherm, Thermodynamic and Mechanistic Insights”, CSJ, vol. 47, no. 4, pp. 714–728, Aug. 2026, doi: 10.17776/csj.1931930.

ISNAD

Durmazuçar, Leyla - Yakar, Selen - Açıkel, Unsal. “Adsorptive Removal of Yellow Dye Using Natural and Magnetic Bentonite: Isotherm, Thermodynamic and Mechanistic Insights”. Cumhuriyet Science Journal 47/4 (August 1, 2026): 714-728. https://doi.org/10.17776/csj.1931930.

JAMA

1.Durmazuçar L, Yakar S, Açıkel U. Adsorptive Removal of Yellow Dye Using Natural and Magnetic Bentonite: Isotherm, Thermodynamic and Mechanistic Insights. CSJ. 2026;47:714–728.

MLA

Durmazuçar, Leyla, et al. “Adsorptive Removal of Yellow Dye Using Natural and Magnetic Bentonite: Isotherm, Thermodynamic and Mechanistic Insights”. Cumhuriyet Science Journal, vol. 47, no. 4, Aug. 2026, pp. 714-28, doi:10.17776/csj.1931930.

Vancouver

1.Leyla Durmazuçar, Selen Yakar, Unsal Açıkel. Adsorptive Removal of Yellow Dye Using Natural and Magnetic Bentonite: Isotherm, Thermodynamic and Mechanistic Insights. CSJ. 2026 Aug. 1;47(4):714-28. doi:10.17776/csj.1931930

As of 2026, Cumhuriyet Science Journal will be published in six issues per year, released in February, April, June, August, October, and December

Adsorptive Removal of Yellow Dye Using Natural and Magnetic Bentonite: Isotherm, Thermodynamic and Mechanistic Insights

Abstract

Keywords

Supporting Institution

Project Number

Ethical Statement

Thanks

References

Details

Primary Language

Subjects

Journal Section

Authors

Publication Date

Submission Date

Acceptance Date

Published in Issue

DOI

IZ

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