Methylene blue removal using nano-TiO₂/MWCNT/Chitosan hydrogel composite beads in aqueous medium

Dyestuff, one of the most hazardous compounds in terms of threats to people and the environment, is found in wastewater from industrial usage. The removal of Methylene Blue (MB) from a water-based medium has been studied by numerous researchers using a variety of adsorbents. To remove MB from aqueous solution, nano-TiO₂/MWCNT/Chitosan hydrogel composite beads (n-TiO₂/MWCNT/Cht) were developed in this study using a sol-gel method. This research discusses the characterisation of a new adsorbent substance using Infrared Spectroscopy (FT-IR) analysis and scanning electron microscopy (SEM). The optimal pH, adsorbent dosage, duration, and starting concentration were ascertained by analyzing the removal efficiencies of MB using the batch adsorption method. Adsorption behaviour at the equilibrium state has been investigated using a variety of adsorption isotherms, including Freundlich, Langmuir, and Dubinin-Radushkevich. The Langmuir adsorption isotherm has been useful to clarify adsorption behaviors. nTiO₂-Cht/MWCNT had an adsorption capacity of 80.65 mg/g for MB. The pseudo-second-order kinetic model offered the best agreement to the experimental data for the adsorption of MB. Kinetic models of pseudo-first-order and pseudo-second-order were employed to explore the adsorption processes of MB on the n-TiO₂/MWCNT/Cht. This study demonstrated the efficiency of n-TiO₂/MWCNT/Cht for the removal of MB from a water-based solution.