Using deep eutectic solvent dissolved low-value cotton linter based efficient magnetic adsorbents for heavy metal...

Area of Science:

• Materials Science
• Environmental Chemistry
• Nanotechnology

Background:

• Developing efficient adsorbents for heavy metal removal is crucial for wastewater treatment.
• Cotton linter (CL) is an abundant, low-value cellulosic material with potential for modification.
• Iron oxide nanoparticles (Fe₃O₄) offer magnetic properties and enhanced adsorption capabilities.

Purpose of the Study:

• To synthesize a novel magnetic bio-adsorbent using cotton linter (CL), deep eutectic solvents (DESs), and Fe₃O₄ nanoparticles.
• To evaluate the adsorption capacity and mechanism for copper ions (Cu²⁺) using the synthesized adsorbent.
• To explore the potential of low-value cotton linter for creating high-performance wastewater treatment materials.

Main Methods:

• Modification of cotton linter (CL) cellulose with Fe₃O₄ magnetic nanoparticles and deep eutectic solvents (DESs).
• Adsorption experiments to determine the capacity for Cu²⁺ under varying conditions (pH, stirring rate, temperature).
• Analysis using Langmuir and Freundlich isothermal models and quasi-second-order kinetic model to understand adsorption behavior.

Main Results:

• The synthesized Fe₃O₄/CL-DES adsorbent exhibited a high adsorption capacity of 93.1 mg g^-1 for Cu²⁺ under optimal conditions (pH 6.0, 300 rpm, 30 °C).
• Fe₃O₄ nanoparticles enhanced hydroxyl group content, improving ion-exchange capacity.
• DES treatment decreased crystallinity and increased amorphous regions, boosting Cu²⁺ chelation and surface adsorption.
• Adsorption followed Freundlich isotherm model (multilayer adsorption) and quasi-second-order kinetics, indicating complex adsorption mechanisms.

Conclusions:

• The novel magnetic bio-adsorbent derived from cotton linter demonstrates excellent efficiency for Cu²⁺ removal.
• The synergistic effect of Fe₃O₄ nanoparticles and DES modification significantly enhances adsorption performance.
• This study presents a promising and sustainable approach for utilizing low-value biomass in wastewater treatment applications.