Adsorptive removal of phosphate by a nanostructured Fe–Al–Mn trimetal oxide adsorbent

Simultaneous phosphate and ammonium removal from aqueous solution by a hydrated aluminum oxide modified natural zeolite

“…Al (Figure 3) shows the lowest phosphate removal at pH below than 2; and the highest with a plateau between pH 3 and 6 to decreases then from pH 6 to 11. The sorption mechanism of phosphate oxyanions (H2PO4 --HPO4 2--PO4 3-) is associated with the formation of complexes with the hydroxyl surface groups of the hydrated aluminum oxide layer impregnated on the zeolite structure (specific adsorption) [17,[43][44][45] or by means of columbic forces depending of the pHpzc (non-specific adsorption) [13,23,45].…”

“…6) [17,46,47]. Then, an increase of pH above 11 is traduced in the gradual conversion of the HPO4 2-onto PO4 3-and consequently, a reduction of the phosphate removal.…”

“…However, they have been rarely used for phosphate sorption due to the constant negative charge on their surface [12]. In order to improve the ion exchange capacity of natural zeolites for anionic species the incorporation or impregnation of iron and aluminum oxides, are the most widespread and excellent candidates for phosphate removal [13][14][15][16][17][18]. Zeolites exhibit different properties which depend on the geological location and they deserve a detailed characterization [19,20].…”

Characteristics of biochar derived from marine macroalgae and fabrication of granular biochar by entrapment in calcium-alginate beads for phosphate removal from aqueous solution

“…At solution pH 2, most of the phosphorus species are formed as H 3 PO 4 , which is weakly attached to the sites of the adsorbent. As the solution pH increases, however, H 2 PO 4 À and HPO 4 2À are superior in solution form when the solution pH is 6.0 < pH 7.21 and 7.21 < pH < 9.0, respectively, and the former has lower adsorption free energy, meaning that it can be more actively adsorbed on the adsorbent than the latter (Fang et al, 2014;Lǚ et al, 2013). In addition, the point of zero charge (pH pzc ) for this study was 8.42, and as results, the surface charge of LB-CAB became protonated at pH < pH pzc .…”

Granulation of Cobalt-containing Nickel Hydroxide with Polyethylene Terephthalate and its Phosphate Ion Adsorption Capability

“…Composite metal oxides may show different physicochemical properties from those of their single-component counterparts [22]. For instance, Al-Fe hydroxide, mesoporous Cr-Zr binary oxide nanoadsorbent, hydrous zirconium oxide-based nanocomposites, and Fe-Al-Mn trimetal oxide have been reported as phosphate-ion-removal agents [24][25][26][27]. In addition, we previously reported that nickel hydroxide, cobalt hydroxide, and cobalt-containing nickel hydroxide show sufficient capabilities for phosphate ion adsorption [20,22,28].…”