Enhanced fluoride removal using montmorillonite clay modified with CoFe₂O₄ and metal-organic frameworks

Area of Science:

• Materials Science
• Environmental Chemistry
• Water Treatment

Background:

• Fluoride contamination in water poses significant health risks.
• Conventional water treatment methods for fluoride removal can be inefficient or costly.
• Modified clays offer a promising avenue for developing effective adsorbents.

Purpose of the Study:

• To synthesize and characterize a novel adsorbent material for fluoride removal.
• To investigate the adsorption performance of modified montmorillonite clay.
• To optimize fluoride adsorption using response surface methodology.

Main Methods:

• Montmorillonite clay (MMt) was modified with CoFe2O4 magnetic particles and Al-Fe fumarate metal-organic framework (Al-Fe Fum).
• Adsorbent properties were analyzed using various characterization techniques, including BET surface area analysis.
• Fluoride adsorption efficiency was evaluated using response surface methodology-central composite design (RSM-CCD).

Main Results:

• The modified MMt/CoFe2O4/Al-Fe Fum exhibited a significant increase in BET surface area (from 13.217 to 365.80 m²/g).
• The RSM-CCD model demonstrated high significance (F-value=783.09, p<0.0001) with excellent fit (R²=0.998).
• Adsorption followed pseudo-second-order kinetics and the Freundlich isotherm model, indicating heterogeneous surface interactions.

Conclusions:

• The synthesized MMt/CoFe2O4/Al-Fe Fum is a highly efficient adsorbent for fluoride removal from aqueous solutions.
• The adsorbent material demonstrated excellent reusability, maintaining over 90% efficiency after multiple cycles.
• The study highlights the potential of modified clays for sustainable water treatment applications.