Titanium Hydroxide as a New Inorganic Fluoride Ion Exchanger.

Abstract

Although TiO2 exhibits a small fluoride ion exchange capacity, it was found that titanium hydroxide, Ti(OH)4, can exchange fluoride ion with large saturation capacity of 1.60m• mol/g. Although the H2PO4 in terferes with the F exchange, the amount of F exchange of Ti(OH)4 was hardly changed by the coexis tence of Cl-, NO3-, and SO42-. The capacity for F-exchange was almost unchanged over 4 times repetition of ion-exchange and desorption and furthermore, the elution of Ti was negligibly small. Consequently, Ti(OH)4 is expected to be a new inorganic F-exchanger for the removal of fluoride ion from wastewater.

Removal of fluoride from water through ion exchange by mesoporous Ti oxohydroxide

“…As discussed in our previous study [12], Ti(OH) 4 prepared by precipitation from TiOSO 4 exhibited fluoride ion exchange properties. In order to improve the ion exchange capacity, Ti(OH) 4 has been prepared by sol-gel hydrolysis using titanium isopropoxide.…”

“…On the other hand, it was reported that CeO 2 is able to exchange fluoride ions selectively [11]. CeO 2 dispersed into polymer matrix is a commercial fluoride ion exchanger (Read-F, Asahi Kasei Co. Ltd.) [12]. However, it is expensive in term of cost.…”

A Review on Adsorption of Fluoride from Aqueous Solution

“…Hydrous titanium dioxide (TiO 2 ) has been found to be a potential selective adsorbent for fluoride ions, as well as halogens and arsenic compounds. Ishihara et al [ 161 ] demonstrated the potential for selective adsorption of fluoride ions, and the characteristics of the adsorption-desorption cycle with titanium tetrahydroxide dry powder, Ti(OH) 4 . To apply the titanium hydroxide to highly effective equipment by loading column, mesoporous materials, brushes, etc.…”

Post-synthesis, characterization and catalytic properties of fluorine-planted MWW-type titanosilicate

“…The F À species could be removed by anion-exchange in aqueous sodium hydroxide. 33 A selective removal of the F species is preferred by employing a more moderate compound instead of alkali hydroxide because a severe alkali treatment unquestionably poisons the active sites of titanosilicates. 34,35 Furthermore, Yamashita et al demonstrated that a cationguest interaction improved the catalytic activity effectively in molecular sieve-based catalytic systems.…”