Iron oxide (Fe2O3) prepared via green route and adsorption efficiency evaluation for an anionic dye: kinetics, isotherms and thermodynamics studies

Abstract

Textile sector is one of the major industries responsible for water pollution and the remediation of dyes is necessary to safe guard the water resources. Adsorption using nanoadsorbents have been emerged as one of viable techniques to eliminate the dyes from wastewater. Iron oxide was prepared via green route using Fan palm (F.P), Dombeya wallichii (D.W) and Pyrus comminis (P.C) as a reducing, capping and stabilizing agents. The adsorption of anionic dye using nanoadsorbents was studied and pH, adsorbent dose, contact time, temperature and concentration of dye were optimized. The maximum dye adsorption was achieved at pH 3, 0.01 g/50 mL adsorbent dose, 200 mg/L initial concentration at 65 °C. Thermodynamic study revealed that the adsorption on to nanoadsorbents was an endothermic process. Langmuir model and pseudo-second-order fitted well to the dye adsorption data. The presence of detergents and surfactants affected the dye adsorption on to nanoadsorbents. Efficient desorption was attained using 0.5 N sodium hydroxide. Results revealed that iron oxide prepared via green route is an efficient adsorbent for the removal of anionic dye and could possibly be used for the remediation of textile effluents.

Keywords

• Biogenic synthesis
• Iron oxide:plant extracts
• Anionic dye
• Adsorption–desorption
• Kinetics
• Thermodynamics