Arsenic (V) adsorption on Fe3O4 nanoparticle-coated boron nitride nanotubes

Abstract

Multiwalled boron nitride nanotubes (BNNTs) functionalized with Fe<inf>3</inf>O<inf>4</inf> nanoparticles (NPs) were used for arsenic removal from water solutions. Sonication followed by a heating process was developed to in situ functionalize Fe<inf>3</inf>O<inf>4</inf> NPs onto a tube surface. A batch of adsorption experiments conducted at neutral pH (6.9) and room temperature (25°C) and using the developed nanocomposites revealed effective arsenic (V) removal. The Langmuir, Freundlich, and Dubinin-Radushkevich adsorption isotherms were measured for a range of As(V) initial concentrations from 1 to 40mg/L under the same conditions. The equilibrium data well fitted all isotherms, indicating that the mechanism for As(V) adsorption was a combination of chemical complexation and physical electrostatic attraction with a slight preference for chemisorption. The magnetite NPs functionalized on BNNTs led to a simple and rapid separation of magnetic metal-loaded adsorbents from the treated water under an external magnetic field. © 2011 Elsevier Inc.