ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Removal kinetics, thermodynamics and adsorption mechanism of anionic and cationic textile dyes using Suillus collinitus mushroom

Özgür Çakmakcı

Kazım Karabekir Vocational School, Environmental Health Program, Karamanoglu Mehmetbey University, Karaman, Turkey

E-mail: ozgurcakmakci@kmu.edu.tr

Received: 15 June 2025  Accepted: 19 July 2025

Abstract:

In this study, the biosorption processes of Methylene Blue (MB), Basic Blue 41 (BB41), Reactive Red 120 (RR120), Methyl Red (MR) and Trypan Blue (TB) dyes were investigated using Suillus collinitus (S. collinitus). Scanning electron microscopy (SEM), isotherm, kinetic and thermodynamic, Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) analyses were performed to determine the biosorption mechanism and characterization. Optimization of factors such as initial dye concentration, adsorbent’s dose, reaction time, pH and temperature affecting the biosorption process was carried out. The highest removal efficiencies were obtained for MB and BB41, 82.52% and 88.224%, respectively. The biosorption capacities of MB, BB41, RR120, MR and TB dyes were 61.35, 123.46, 56.82, 50.00, and 54.35 mg/g, respectively. The adsorption equilibrium data showed best fit to the Temkin isotherm for MB and MR, the Freundlich isotherm for BB41 and RR120, and the Dubinin–Radushkevich (D–R) isotherm for TB. The kinetic model that best explained the biosorption process for all dyes was pseudo-second-order (R² > 0.99). Thermodynamic analyses showed that biosorption was exothermic (ΔH^o < 0) for MB and BB41 and endothermic (ΔH^o > 0) for RR120, MR and TB; however, the enthalpy values remained below 40 kJ/mol for all dyes, indicating that physisorption is the dominant mechanism. Gibbs free energy change (ΔG^o) was negative at all temperatures, confirming that the biosorption process was spontaneous. It offers a sustainable biosorbent alternative thanks to its high surface area, natural porosity structure and low cost.

Graphical abstract

Keywords: Suillus collinitus mushroom; Biosorption mechanism; Dye removal; Biosorption; Kinetics

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-025-04272-5

Chemical Papers 79 (11) 7567–7584 (2025)