Clinoptilolite-Based Adsorbents for Paracetamol Removal.

Area of Science:

• Environmental Science
• Materials Science
• Analytical Chemistry

Background:

• Pharmaceuticals like paracetamol contaminate water sources.
• Natural zeolites, such as clinoptilolite, are potential adsorbents.
• Surface properties significantly influence adsorption efficiency.

Purpose of the Study:

• To investigate paracetamol adsorption using natural clinoptilolite (p-CLI) and modified forms (H-CLI, o-CLI).
• To compare the adsorption capacities of proton-exchanged and surfactant-modified clinoptilolite.
• To understand how structural and surface changes affect pharmaceutical uptake.

Main Methods:

• Clinoptilolite modification via ammonium exchange/calcination (H-CLI) and HDTMA-Br treatment (o-CLI).
• Material characterization using XRD, FT-IR, and SEM.
• Batch adsorption experiments followed by differential pulse voltammetry (DPV) for quantification.

Main Results:

• XRD confirmed preserved clinoptilolite framework post-modification.
• H-CLI showed partial cation removal; o-CLI developed a hydrophobic organic layer.
• Adsorption capacity increased from negligible for p-CLI to ~0.15 mg/g for H-CLI and ~0.25 mg/g for o-CLI.

Conclusions:

• Surface functionalization enhances clinoptilolite affinity for weakly polar pharmaceuticals like paracetamol.
• HDTMA modification yielded higher adsorption than proton exchange due to increased hydrophobicity.
• Despite improvements, clinoptilolite adsorption capacities for paracetamol remain limited.