Highly selective and efficient removal of fluoride from aqueous solution by Zr La dual-metal hydroxide anchored bio-sorbents

The pomelo peel was used as a bio-carrier for anchoring the dual-metal hydroxide (Zr La), forming the Zr La/PP composites. Morphology properties of the Zr La/PP composites indicated that a large amount of Zr La dual-metal hydroxides were self-aggregated on the virgin biomaterials, forming the different sizes (10–100 nm) of nano-structured aggregates on the Zr La/PP composites. The Zr distribution corresponded well to the dispersed La in the Zr La/PP composites. Fluoride capture by Zr La/PP composites increased with the increase in temperature. The preferential fluoride adsorption by the Zr La/PP composites can also be achieved in magnitudes of coexisting ions. The Zr La/PP composites exhibited a promising fluoride adsorption capacity with a significantly excellent stability. Several column adsorption-desorption cycles exhibited that there were no significant loss in fluoride capacity; this indicated the high adsorption stability of Zr La/PP composites. Based on all results above, it was suggested that the Zr La/PP composites could be used as a promising adsorbent for fluoride removal in real application.