Extraction of Pb²⁺ from dilute solution by paramagnetic Fe₃O₄ @ SiO₂ @ Clpr-silica @ dithizone solid-phase nanoextractant

Abstract

A paramagnetic solid phase nanoextractant, Fe₃O₄ @ SiO₂ @ Clpr-silica @ dithizone, is firstly constructed for separating Pb²⁺ from dilute solution. The special extractant is composed of a paramagnetic Fe₃O₄ nanomaterials core, amorphous silica, chloro-propyl silane coupling agent, and dithizone from inside to outside. The experimental results demonstrate the as-obtained extractant fine adsorbability, high adsorption and desorption speed, wide acidic resistance, facile separability, and admirable reusability. The adsorption capacity of the extractant exceeds 63.4 mg g⁻¹, and the adsorption process is accomplished in 25 s. Pb²⁺ ions are completely eluted from the extractant immersed into 2 M HNO₃ solution in 20 s. After five times of adsorption-regeneration cycles, no significant loss of adsorption capacity is observed, indicating the good stability of the extractant.

Keywords:

• Magnetic separation
• Nanocomposite
• Solid-phase extracting
• Lead ion
• Heavy metal ions

Acknowledgment

The authors are thankful to the national natural science foundation of China (No. 20906061) for financial supports.