Ceria nanoparticles supported on carbon nanotubes for the removal of arsenate from water

A novel adsorbent, ceria supported on carbon nanotubes (CeO2-CNTs), was developed for the removal of arsenate from water. The experiments show that CeO2-CNTs is an effective adsorbent for arsenate, and the adsorption is pH-dependent. Ca2+ and Mg2+ significantly enhanced its adsorption capacity, which suggests that it is a promising adsorbent for drinking water purification. Under natural pH conditions, an increase from 0 to 10 mg/L in the concentration of Ca2+ and Mg2+ results in an increase from 10 to 81.9 and 78.8 mg/g in the amount of As(V) adsorbed, respectively. The loaded adsorbent can be efficiently regenerated by diluted NaOH, and a regeneration efficiency of 94% was achieved using 0.1 mol/L NaOH. The adsorption mechanism was also suggested.