Enhancing Pb²⁺ removal using a novel cerium-based metal organic framework: Post-synthetic modification and response...

Area of Science:

• Environmental Chemistry
• Materials Science
• Nanotechnology

Background:

• Heavy metal contamination, particularly lead (Pb²⁺), in water poses significant environmental and health risks.
• Effective and sustainable remediation strategies are crucial for ensuring water safety and compliance with regulatory standards.

Purpose of the Study:

• To develop and evaluate a novel Cerium (Ce)-based metal-organic framework, Ce-MOF-808, functionalized with 3-aminopropyltriethoxysilane (APTES) for efficient Pb²⁺ removal from aqueous solutions.
• To investigate the adsorption performance, kinetics, thermodynamics, and optimize the process for lead remediation.

Main Methods:

• Synthesis of Ce-MOF-808 at ambient temperature followed by APTES grafting using a hydrothermal method.
• Characterization of the synthesized Ce-MOF-808-APTES material using various analytical techniques.
• Batch adsorption experiments to assess the impact of pH, adsorbent dose, initial concentration, temperature, and contact time on Pb²⁺ removal.
• Kinetic, isotherm, and thermodynamic modeling to understand the adsorption mechanism.
• Optimization of adsorption conditions using Response Surface Methodology (RSM) with Central Composite Design (CCD).

Main Results:

• Ce-MOF-808-APTES demonstrated high removal efficiency (99.87%) for Pb²⁺ at 10 ppm, reducing residual levels to 0.01 ppm, meeting WHO standards.
• The adsorption process followed pseudo-second-order kinetics and Langmuir isotherm models, indicating a maximum adsorption capacity of 184.32 mg g^-1.
• Thermodynamic analysis confirmed the adsorption as spontaneous and exothermic.
• RSM optimization yielded a robust quadratic model (R² = 0.99) for predicting optimal conditions.

Conclusions:

• Ce-MOF-808-APTES is a highly efficient and promising adsorbent for lead remediation from contaminated water.
• The material's performance meets regulatory standards, highlighting its potential for practical wastewater treatment applications.
• Further research is warranted to explore its efficacy for other heavy metal contaminants.