Preparation, characterization and dye adsorption properties of biocompatible composite (alginate/titania nanoparticle)

In this paper, the preparation, characterization and dye adsorption properties of novel biocompatible composite (Sodium Alginate/titania nanoparticle) (SA/n-TiO2) were investigated. Titania nanoparticles were immobilized onto Sodium Alginate. Physical characteristics of SA/n-TiO2 were studied using Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), and wavelength dispersive X-ray spectroscopy (WDX). Two textile dyes, Direct Red 80 (DR80) and Acid Green 25 (AG25), were used as model compounds. The effect of operational parameter such as SA/n-TiO2 dosage, initial dye concentration and pH was evaluated at 25 °C. The isotherm, kinetic and thermodynamic of dye adsorption were studied. The data were evaluated for compliance with the different isotherm models. It was found that DR80 and AG25 followed with Langmuir isotherm. Adsorption kinetic of dyes was found to conform to pseudo-second order kinetics. The thermodynamic data showed that adsorption process was spontaneous, endothermic and physisorption reaction. Based on the data of present investigation, one could conclude that the SA/n-TiO2 being a biocompatible, eco-friendly and low-cost adsorbent might be a suitable alternative for elimination of dyes from colored aqueous solutions.

Research Highlights
► Dye adsorption isotherm onto SA/n-TiO2 composite followed Langmuir isotherm.
► Dye adsorption kinetic onto SA/n-TiO2 composite followed pseudo-second order.
► Dye adsorption onto SA/n-TiO2 was an endothermic and physisorption reaction.