Kinetics and thermodynamics of Isolan Bordeaux 2S-B dye adsorption on chemically synthesized graphene particles

Abstract

Dyes in wastewater are highly toxic pollutants that have negative physical, chemical, and ecological effects on aquatic ecosystems even at low concentrations. In this study, the efficiency of chemically synthesized graphene oxide (CG) for the removal of the organic dye Isolan Bordeaux 2S-B and the principles of adsorption were investigated. Scanning electron microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR) analyses were performed to characterize the CG, and the point of zero charge value was determined. The optimal conditions were found to be a pH of 2, an adsorbent dosage of 0.2 g, and a reaction time and temperature of 30 min and 25 °C, respectively. The adsorption equilibrium data fitted well with the Langmuir isotherm (R² =0.98, RMSE = 0.38). The adsorption kinetics data followed a pseudo-second-order kinetic model (R² = 0.99). Thermodynamic studies have shown that adsorption is exothermic and spontaneous. Desorption-regeneration studies demonstrated that CG is a highly stable adsorbent, and experiments in the presence of foreign ions show that it has a high selective affinity for anionic dyes. CG is effective not only in removing IB 2S-B but also shows promise in selectively removing anionic dyes from wastewater as a long-lasting adsorbent.

Keywords:

• Adsorption
• graphene
• isotherm
• textile dyes
• thermodynamic
• water treatment

Data availability statement

The data supporting the findings of this study are available from the author upon reasonable request.

Disclosure statement

The author reports there are no competing interests to declare.