Understanding the Cu²⁺ adsorption mechanism on activated carbon using advanced statistical physics modelling

Area of Science:

• Environmental Chemistry
• Physical Chemistry
• Materials Science

Background:

• Heavy metal ions, particularly copper (Cu²⁺), pose significant environmental risks.
• Activated carbon is a widely studied adsorbent for water remediation.
• Understanding adsorption mechanisms at the molecular level is crucial for optimizing removal processes.

Purpose of the Study:

• To analyze the adsorption mechanism of copper ions (Cu²⁺) on activated carbons using statistical physics models.
• To gain molecular-scale insights into the interaction between Cu²⁺ and activated carbon surfaces.
• To evaluate the adsorption performance of selected activated carbons for Cu²⁺ removal.

Main Methods:

• Application of statistical physics models to analyze Cu²⁺ adsorption data.
• Correlation of adsorption data using a monolayer adsorption model at varying temperatures (25-55 °C) and pH (5.5).
• Calculation of adsorption energy to determine interaction forces and process thermodynamics.

Main Results:

• A monolayer adsorption model best described Cu²⁺ adsorption on the studied activated carbons.
• The adsorption process was identified as multi-cationic, with Cu²⁺ interacting via single functional groups.
• Calculated adsorption energy indicated an endothermic process driven by physical interactions.
• Saturation adsorption capacities ranged from 54.6 to 87.0 mg/g, outperforming other literature adsorbents.

Conclusions:

• Statistical physics modeling provides valuable insights into the molecular mechanisms of heavy metal adsorption.
• Activated carbons demonstrate high efficiency for copper ion removal, with a monolayer adsorption mechanism.
• The findings contribute to the development of effective strategies for removing water pollutants.