Thorium removal by different adsorbents

Area of Science:

• Environmental Science
• Materials Science
• Radiochemistry

Background:

• Radiotoxic thorium (Th(4+)) poses environmental risks in aqueous solutions.
• Effective removal of thorium is crucial for environmental remediation and safety.

Purpose of the Study:

• To evaluate the thorium removal capabilities of activated carbons and various zeolites.
• To compare the adsorption performance of different adsorptive materials for thorium ions.

Main Methods:

• Activated carbons prepared from solvent extracted olive pulp (SEOP) and olive stone (OS) via steam activation.
• Characterization of carbons using N(2) adsorption, Hg porosimetry, and iodine number.
• Adsorption experiments using natural (clinoptilolite, mordenite) and synthetic (NaX, NaA) zeolites, pretreated or in sodium form.
• Fitting adsorption data to Langmuir and Freundlich models.

Main Results:

• Activated carbons exhibited better thorium removal than natural clinoptilolite.
• SEOP-derived carbon showed higher removal than OS-derived carbon and natural mordenite.
• Synthetic zeolites (NaX, NaA) demonstrated the highest thorium removal efficiency.
• Langmuir model provided the best fit for adsorption data, yielding adsorption constants and capacities.

Conclusions:

• Synthetic zeolites are highly effective for thorium removal due to their structure and ion-exchange capacity.
• Activated carbon performance is linked to surface functional groups.
• The Langmuir model accurately describes thorium adsorption onto these materials.