Fabrication of hydroxyapatite embedded cerium-organic frameworks for fluoride capture from water

Defluoridation using hydroxyapatite implanted lanthanum organic framework-based bio-hybrid beads

“…The negative Δ G ° value reveals that the fluoride adsorption route was spontaneous in nature. 68 The Δ S ° positive value reveals the raises in the randomness with raises in the number of active sites of the adsorbent at the solid–liquid interface. The positive Δ S ° value reveals the irreversible nature of the fluoride adsorption process, therefore confirming the endothermic action of fluoride adsorption by positive Δ H ° values.…”

Treatment of fluorinated wastewater with chitosan modified activated sludge lysis ash

“…ν Si–O ; the out-of-plane bending vibration peak of carbonate, γ CO 3 , is predominant near 876 cm −1 ; the bimodal structure near 799 and 777 cm −1 is typical of the Si–O stretching vibration peak of quartz, ν Si–O, and the in-plane bending vibration peak of carbonate, δ CO 3 is predominant near 726 cm −1 ; the peak near 604 and 567 cm −1 may be the bending vibration peak of phosphate, δ PO 4 ;and the peak near 468 cm −1 is mainly the bending vibration peak of some Si–O bonds δ Si–O (containing Si–O–Si, Si–O–Al, Si–O–Mg, and Si–O–Fe structures). 28 These oxygen-containing functional groups are electron-absorbing groups, which strengthen the electrostatic attraction of activated carbon and facilitate the adsorption process. Compared with that before modification, the position of the characteristic absorption peaks basically did not change but was enhanced.…”

Performance of Rod-Shaped Ce Metal–Organic Frameworks for Defluoridation

“…The zero-point charge (pH zpc ) was measured via the pH drift method [36]. In a 50 mL volumetric flask, 50 mL NaCl solution (0.1 mol L −1 ) was measured, the pH was set at 3-10 using NaOH or HCl, 0.01 g of Ce-H3TATAB-MOFs was added, and the reaction was shaken with the temperature and time of 25 • C and 12 h, respectively.…”