Optimized Congo Red Dye Adsorption Using ZnCuCr-Based MOF for Sustainable Wastewater Treatment

Area of Science:

• Materials Science
• Environmental Chemistry
• Nanotechnology

Background:

• Conventional adsorbents often lack the stability and efficiency required for effective dye removal from wastewater.
• Developing advanced materials with enhanced adsorption properties is crucial for environmental remediation.
• Metal-organic frameworks (MOFs) offer tunable structures and high surface areas, making them promising candidates for pollutant removal.

Purpose of the Study:

• To synthesize and characterize a novel trimetallic ZnCuCr-TpIm metal-organic framework (MOF).
• To evaluate the MOF's efficiency in removing Congo red dye from aqueous solutions.
• To assess the stability, reusability, and performance of the MOF under various wastewater conditions.

Main Methods:

• Solvothermal synthesis of cubic ZnCuCr-TpIm MOF crystals (300-500 nm).
• Adsorption experiments to determine optimal conditions (dosage, temperature, pH, contact time) for Congo red removal.
• Kinetic (pseudo-second-order) and isotherm (Langmuir) modeling to understand adsorption mechanisms.
• FTIR and XRD analysis to confirm structural integrity and dye-framework interactions.
• Stability tests including surface area retention, reusability cycles, and metal ion leaching assessments.

Main Results:

• The ZnCuCr-TpIm MOF achieved a 96.5% Congo red removal efficiency under optimal conditions.
• Adsorption followed pseudo-second-order kinetics and Langmuir isotherm models, with a maximum adsorption capacity of 325 mg/g.
• The MOF demonstrated excellent stability, retaining 95% surface area after 72h and >90% efficiency after five reuse cycles.
• Minimal metal ion leaching (<1.2 ppm) and high resilience in simulated wastewater conditions were observed.

Conclusions:

• The trimetallic ZnCuCr-TpIm MOF exhibits superior adsorption performance and stability compared to conventional materials.
• The synergistic effect of Zn, Cu, and Cr metal centers contributes to enhanced dye removal efficiency.
• This MOF is a promising, sustainable adsorbent for efficient and long-term wastewater treatment applications.