Mg-Al]-LDH and [Zn-Al]-LDH as Matrices for Removal of High Loadings of Phosphate

Abstract

Eutrophication is an undesirable environmental process that occurs in water bodies affected by high concentrations of phosphate. Different economic sectors are responsible for discharge effluents with extremely high phosphate content. Therefore, is important to develop technologies capable of remove phosphate from these effluents, before that reach other and larger water bodies. This work proposes the use of layered double hydroxide (LDH) as an adsorbent matrix for phosphate removal from aqueous solution. Different isomorphic structure of LDH ([Mg-Al]-LDH and [Zn-Al]-LDH) were employed to incorporate loadings of phosphate by ion exchange. The obtained materials were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR), and thermal analysis (TG/DTG). The crystalline structure of [Mg-Al]-LDH was preserved after phosphate adsorption, however the performance was low in comparison to [Zn-Al]-LDH, for which a high phosphate removal efficiency of 116.07 mg P. g-1 of LDH was achieved. The [Zn-Al]-LDH material showed good potential for use as matrix for the adsorption of phosphate in effluents.