| Abstrakt: |
Mesostructured silica monoliths were synthesized using a simple reproducible strategy of an instant direct templating with nonionic Brij-35 copolymer surfactant and C12 alkane (dodocane). The synthesized silica monoliths were first immobilized with 3,3-glycidoxypropyltrimethylsilane (GPS), which was followed by the reaction with ethylenediamine (EDA) to produce SiO2@GPS-EDA worm-like mesoporous silica monoliths. SiO2@GPS-EDA was characterized by SEM, SEM-EDX mapping, HR-TEM, EDS, elemental analysis, zeta potential, nitrogen adsorption/desorption isotherms, and pore size distribution measurements. Our results show that Brij-35/dodocane can be used to fabricate uniformly mesochannel pores of silica monoliths. EDS, SEM-EDX mapping, and elemental analysis of SiO2@GPS-EDA demonstrate the presence of C (16.25%), H (1.75%), and N (5.45%) embedded into the silica pore surface frameworks. Batch adsorption experiments were carried out to evaluate the sorbent efficiency. The SiO2@GPS-EDA mesoporous adsorbent efficiently removes thorium ions from aqueous solutions. The highest adsorption of Th(IV) ions, 94.8 mg g–1, was observed at pH 4.0 (equilibration time 120 min). The adsorption of Th(IV) ions onto the sorbent follows the Langmuir, pseudo-second-order, intraparticle diffusion, and Dubinin–Radushkevich models. The adsorbed Th(IV) ions were eluted and recovered with 0.1 M HNO3. The absorbent was successfully applied to Th(IV) extraction from the monazite leach liquor. The prepared porous organic-inorganic hybrid sorbent showed sensitivity, selectivity, reusability, and fast kinetics in Th(IV) adsorption from aqueous solutions. [ABSTRACT FROM AUTHOR] |
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