Adsorption of dyes from aqueous solutions using chitosan-based materials functionalized with ionic liquids: Acid...

Area of Science:

• Materials Science
• Environmental Chemistry
• Chemical Engineering

Background:

• Textile industry wastewater poses environmental challenges due to persistent dye contamination.
• Conventional dye removal methods often lack efficiency, scalability, or sustainability.
• Chitosan (CS) and ionic liquids (ILs) show promise as adsorbent materials but require optimization for dye removal.

Purpose of the Study:

• To develop and characterize a novel composite adsorbent, ILCS-CS-Glu, for efficient anionic dye removal.
• To evaluate the adsorption performance, kinetics, and thermodynamics of ILCS-CS-Glu for Acid Orange 7 (AO7).
• To assess the adsorbent's stability, reusability, and applicability in real textile industrial effluent.

Main Methods:

• Grafting an ionic liquid ([C8MIMBr]Br) onto a chitosan matrix, blended with unmodified CS, and crosslinked with glutaraldehyde.
• Adsorption experiments to determine maximum adsorption capacity, pH, and ionic strength effects.
• Kinetics, isotherm, desorption, and regeneration studies to understand adsorption mechanisms and material stability.

Main Results:

• ILCS-CS-Glu achieved a high maximum adsorption capacity of 292 mg/g for AO7.
• High adsorption efficiency (>90%) was maintained across a wide pH range (3-9) and ionic strength (up to 1.0 M NaCl).
• The adsorbent demonstrated excellent reusability and stability over multiple cycles, with 83% dye removal in textile effluent.

Conclusions:

• ILCS-CS-Glu is a highly effective, stable, and reusable adsorbent for anionic dyes.
• The composite material shows significant potential for sustainable textile wastewater treatment.
• Its performance under varying pH and salinity conditions makes it a robust solution for industrial applications.