Evaluation of the various adsorption isotherm models for the photocatalytic removal of methylene blue from the wastewater by graphene oxide/TiO۲/SiO۲

Treatment of wastewater is a crucial step in reducing pollution from the textile and dyeing industries. One of the best techniques for dye removal is photocatalytic processes, and TiO۲ is frequently employed in numerous wastewater treatment applications. In this study, different adsorption isotherm models and experimental data from the removal of the methylene blue dye from wastewater by applying GO/TiO۲/SiO۲ nanocomposite were compared. The correlation coefficient values (R۲) for the Langmuir isotherm type ۱ (Hanes-Woolf), Temkin, and Freundlich were determined to be, respectively, ۰.۹۹۵۷, ۰.۹۸۲۳, and ۰.۹۵۱۵. Additionally, the R۲ values for the Redlich-Peterson, Sips, and Toth isotherms models were ۰.۹۵۷۵, ۰.۹۶۲۶, and ۰.۹۶۲۹, respectively. Therefore, Langmuir isotherm type ۱ has the highest R۲ and is the best model for surface adsorption of methylene blue on GO/TiO۲/SiO۲ photocatalyst. As a result, monolayer adsorption was most likely dominating during the adsorption. Furthermore, this photocatalyst proved suitable for lower methylene blue concentrations and systems with lower temperature sensitivity.

Keywords:

Graphene oxide/TiO۲/SiO۲ , photocatalyst , Methylene Blue , Wastewater , Isotherms