Modified Ordered Mesoporous Carbons for Cr(VI) Removal from Wastewater

Area of Science:

• Materials Science
• Environmental Chemistry
• Nanotechnology

Background:

• Hexavalent chromium (Cr(VI)) poses significant environmental and health risks.
• Developing efficient adsorbents for Cr(VI) removal is crucial for wastewater treatment.

Purpose of the Study:

• To synthesize and characterize Zr/Fe-modified CMK-3 carbon for Cr(VI) adsorption.
• To investigate the adsorption mechanism and efficiency of the modified carbon for Cr(VI) removal from aqueous solutions.

Main Methods:

• Ozonization and chemical modification of CMK-3 carbon with Zr and Fe compounds.
• Physicochemical characterization of the synthesized materials.
• Cr(VI) adsorption studies using batch experiments, kinetic and isotherm modeling.

Main Results:

• The Zr/Fe-modified CMK-3 carbon exhibited a high specific surface area (ca. 800 m² g⁻¹) and acidic surface properties.
• The highest static adsorption capacity for Cr(VI) was 50.1 mg g⁻¹ at pH 5.8.
• Adsorption followed Elovich and Freundlich models, with redox reactions likely dominating the mechanism.

Conclusions:

• Zr/Fe-modified CMK-3 carbon is a promising adsorbent for efficient Cr(VI) removal.
• The material demonstrated effective removal (>90%) from model galvanic wastewater.
• Regeneration using HCl and HNO₃ was insufficient, suggesting further research is needed.