Uranium adsorption by biosourced hydroxyapatite with a large specific surface area

Area of Science:

• Environmental Science
• Materials Science
• Chemistry

Background:

• Uranium (U) poses significant chemical toxicity due to its long half-life, with contaminated water being a primary exposure route.
• Effective uranium removal from aqueous systems is crucial for environmental and public health.
• Hydroxyapatite (HA) is recognized as a potent uranium adsorbent, utilizing dissolution/precipitation, surface complexation, and ion substitution mechanisms.

Purpose of the Study:

• To investigate the efficacy of hydroxyapatite (HA) derived from bovine bones using oxidative hydrothermal treatment (OHT) for uranium removal.
• To compare the performance of OHT-derived HA with commercial HA and calcined bovine bone HA.
• To evaluate uranium removal efficiency and extraction capacity across a range of pH conditions.

Main Methods:

• Oxidative hydrothermal treatment (OHT) was employed to derive HA from bovine bones.
• The specific surface area of OHT-derived HA was characterized and compared to other HA sources.
• Uranium removal efficiency and maximum extraction capacity were measured at various pH levels (4-8).

Main Results:

• OHT-derived HA, possessing a large specific surface area, demonstrated over 85% uranium removal efficiency across pH 4-8.
• The highest uranium extraction capacity was observed at pH 4, reaching 1148 ± 17 mg/g.
• OHT-derived HA significantly outperformed previously reported adsorbents in terms of extraction capacity.

Conclusions:

• Hydroxyapatite derived via oxidative hydrothermal treatment of bovine bones is a highly effective adsorbent for removing uranium from water.
• The material's large specific surface area contributes to its superior performance in uranium extraction.
• This method presents a promising, high-capacity adsorbent for addressing uranium contamination in aqueous environments.