Adsorption of Uranium (VI) from Aqueous Solutions by Amino-functionalized Clay Minerals

Abstract

Silylation of clay minerals from Cherkasy deposit (Ukraine) montmorillonite (layer silicate) and palygorskite (fibrous silicate) was performed using organosilane (3-aminopropyl)triethoxysilane (APTES). Solvents with different polarity (ethanol, toluene) were used in synthesis. The structure of modified minerals was characterized by complex of methods (X-ray powder diffraction, Fourier transform infrared spectroscopy, nitrogen adsorption-desorption at −196 °C and thermal analysis). Studies of adsorption characteristics of APTES-modified clay minerals were carried out in relation to uranium (VI). The results indicated that modified montmorillonite and palygorskite were effective materials for water purification from UO22+.

Fabrication of Mesoporous NaZrP Cation-Exchanger for U(VI) Ions Separation from Uranyl Leach Liquors

“…The weight of NaZrP-CEX required to intake UO 2 2+ ions in a concentration ranged from 1 to 100 mg/L in one litter of the containing UO 2 2+ solution was calculated to be 0.825 g/L. The NaZrP-CEX exhibited substantial adsorption efficiency, which is comparable with that of previously prepared in organic adsorbents, such as oxides and phosphates compounds (Table 2) [45][46][47][48][49][50][51][52][53][54].…”

Adsorption of uranium(VI) from groundwater by amino-functionalized clay

“…The prominent species are UO 2 CO 3 , UO 2 (CO 3 ) 2 2− and UO 2 (CO 3 ) 3 4− at pH > 7 [24,35]. The adsorption of UO 2 2+ on amino-functionalized clay at pH < 4.0 is lower, which could be explained by the amino group being protonated to form -NH 3 + at lower pH, so there are only fewer -NH 2 sites available on the sorbents' surface for UO 2 2+ adsorption.…”

“…The species of uranium change in solutions with different pH, which is one of the main factors that control the U adsorption on minerals surface [24]. At pH < 4.0, UO 2 2+ was the main species in the system [33,34].…”

“…In recent years, amino-functionalized adsorbents have been reported as effective materials for adsorbing U(VI) because amino groups can form stable chelates complexes with uranyl ions [18,22,23]. Tobilko et al [24] Prepared 3-aminopropyltriethoxysilane (APTES) modified Na-montmorillonite and Na-palygorskite can effectively remove U(VI) in aqueous solution. The results show that the adsorption performance of amino-functionalized Na-montmorillonite for U(VI) is obviously improved, the maximum adsorption capacity increased from 125 to 337 µmol/g, and the maximum adsorption capacity of amino-functionalized Na-palygorskite increased from 59 to 372 µmol/g.…”

Prospective application of phosphorylated carbon nanofibers with a high adsorption capacity for the sequestration of uranium from ground water

“…11 A recent review on uranium remediation describes a wide variety of inorganic, organic, polymeric, carbon family and porous framework materials. 3 The inorganic materials include clay minerals, 12 metal oxides, 13 layered double hydroxides 14 and mesoporous silica 15 adsorbents. Organic polymers like ion exchange resins, cellulose, chitosan 16,17 etc.…”