Sorption of phosphate ions with materials based on titanium and lanthanum hydroxides

A study of sorption of phosphate ions from aqueous solutions by wood ash

“…The limiting sorption capacity A lim of wood ash for phosphate ions was 5.82 mmol g -1 under the experimental conditions, in agreement with the results of [6,7]. The effective sorption equilibrium constant is 1.301.…”

Tracking Internal Electron Shuttle Using X-ray Spectroscopies in La/Zr Hydroxide for Reconciliation of Charge-Transfer Interaction and Coordination toward Phosphate

“…The additional weaker peaks at 615 and 540 cm –1 , with a shoulder peak at 568, were attributed to the ν 4 vibration from PO 4 3– groups . As a result, compared with the fresh sorbents, phosphate was well adsorbed by the La/Zr hydroxides, which might result in the formation of La/Zr–O–PO 3 species. ,, …”

“…31,32 Notably, the sharp peak at ∼3600 cm −1 , assigned to the stretching mode of OH for the LaOH sample and corresponding to O−H stretching La hydroxides, well matched that of the La(OH) 3 sample. 33,34 The strong peaks below 800 cm −1 were attributed to the formation of Zr−O, La−O, or La− O−Zr chemical bonds via condensation reactions, 35 with the sharp peaks at 425 and 660 cm −1 assigned to the stretching vibration of the La−O bond. 36 Furthermore, the peaks from 1450 to 1600 cm −1 were due to the bending vibration of Zr/ La−OH groups, 24,37,38 and the peaks at 1340, 1385, 1400, and 1440 cm −1 resulted from the bending vibration of CO 3 2− groups, 32 indicating the presence of carbonate impurities in the La/Zr hydroxide during sample preparation.…”

“…39 As a result, compared with the fresh sorbents, phosphate was well adsorbed by the La/Zr hydroxides, which might result in the formation of La/Zr−O−PO 3 species. 34,40,41 To further investigate the enhancement of P adsorption induced by the existence of different metals, we carried out O K-edge XANES, which is a sensitive approach for studying chemical state changes by revealing the O 2p hybridization states with d orbitals. O K-edge XANES spectra of LaOH, LZ2:1, LZ1:1, and ZrOH samples were obtained using totalelectron-yield (TEY) mode, studying excitations from the O 1s orbital to unoccupied states above the Fermi level from regions within 10 nm of the surface (Figure 3a).…”

Фізико-Хімічні Властивості Матеріалів На Основі Гідроксидів Титану Допованих Церієм Та Залізом Синтезованих Двома Методами

“…Numerous methods have been developed and used in the process of water treatment such as magnetic filtration, electro-coagulation, biological and sorption purification [6][7][8][9]. Among a number of materials, hydrated mixed oxides of group-II-IV metals, especially Ti, Fe and Al, synthesized by the most popular method of co-precipitation are suggested for removal of phosphorus and arsenic compounds [10][11][12][13]. It is well known that physico-chemical properties of functional materials largely depend on the synthesis conditions [14][15][16].…”