Simultaneous Sorption of Arsenate and Fluoride on Calcined Mg-Fe-La Hydrotalcite-Like Compound from Water

The co-occurring pollution of arsenate (As(V)) and fluoride (F) in potable water has gained global concern due to its serious threat to the human health. In this work, calcined Mg/Fe/La hydrotalcite-like compound (Mg/Fe/La CHLc) as an adsorbent was fabricated to remove As(V) and F from water simultaneously. The experimental results have shown that the prepared CHLc exhibited pronounced performances for the simultaneous sorption of As(V) and F in water. The maximum sorption capacity of F and As(V) reached 73.8 and 81.4 mg/g, respectively. The simultaneous sorption efficiency was not interfered by the coexisting of F and As(V). After 4 times of desorption-regeneration cycles, the adsorbent still possessed high sorption efficiency. It was demonstrated that the synthesized adsorbent is a good adsorbent for removing As(V) and F from water simultaneously. The mechanisms for the simultaneous sorption are largely attributed to the surface sorption and interlayer sorption of hydrotalcite due to the memory effect. Moreover, the complexation of fluoride with lanthanum, arsenate ligand exchange with hydroxyl and complexation with lanthanum and iron on Mg/Fe/La CHLc played important roles for the simultaneous sorption.