Sulfur- and Nitrogen-Functionalized Al₂O₃ Materials for Enhanced Arsenic Batch Adsorption.

Area of Science:

• Environmental Science
• Materials Science
• Chemistry

Background:

• Arsenic contamination in water poses severe risks to human health and ecosystems.
• Effective methods for arsenic removal from aqueous solutions are crucial for environmental protection.

Purpose of the Study:

• To develop and characterize functionalized aluminum oxide (Al2O3) materials for arsenic adsorption.
• To investigate the factors influencing arsenic adsorption capacity and optimize the adsorbent performance.

Main Methods:

• Al2O3 was functionalized with sulfur and nitrogen species using various precursors.
• Characterization involved N2 adsorption-desorption, FTIR, TGA, XPS, and pHpzc analysis.
• Arsenic adsorption was evaluated using the Langmuir model at different pH levels.

Main Results:

• The maximum arsenic adsorption capacity (qmax) of 246 mg/g was achieved with Al2O3 functionalized with ammonia (NH3) at pH 3.
• Adsorption efficiency was influenced by solution pH, electrostatic interactions, surface modification, and coexisting substances.
• The Al2O3@NH3 adsorbent demonstrated high arsenic removal efficiency in a real water matrix.

Conclusions:

• Functionalized Al2O3, particularly Al2O3@NH3, is a highly effective adsorbent for removing arsenic from water.
• The study highlights the importance of surface functionalization and solution chemistry in optimizing arsenic removal.
• The developed adsorbent shows promise for practical applications in water purification.