Separation of Selenite from Inorganic Selenium Ions using TiO₂Magnetic Nanoparticles

Abstract

A simple and quick separation technique for selenite in natural water was developed using TiO 2 @SiO 2 /Fe 3 O 4 nanoparticles. For the synthesis of nanoparticles, a polymer-assisted sol-gel method using hydroxypropyl cellulose (HPC) was developed to control particle dispersion in the synthetic procedure. In addition, titanium butoxide (TBT) precursor, instead of the typical titanium tetra isopropoxide, was used for the formation of the TiO 2 shell. The synthesized nanoparticles were used to separate selenite (Se 4+) in the presence of Se 6+ or selenium anions for the photocatalytic reduction to Se 0 atom on the TiO 2 shell, followed by magnetic separation using Fe 3 O 4 nanoparticles. The reduction efficiency of the photocatalytic reaction was 81.4% at a UV power of 6W for 3 h with a dark adsorption of 17.5% to the nanoparticles, as determined by inductively coupled plasma-mass spectrometry (ICP-MS). The developed separation method can be used for the speciation and preconcentration of selenium cations in environmental and biological analysis.

A Bibliometric Analysis of Research on Selenium in Drinking Water during the 1990–2021 Period: Treatment Options for Selenium Removal

“…Other research works have proposed the employment of metallic oxides, such as titania, silica or zirconia, for this same purpose [178][179][180][181][182]. In some cases, the developed adsorbents were highly selective to selenite, even in the presence of selenate or selenide [183,184]. Natural and modified zeolites are high-performance adsorbents that have been implemented in the treatment of drinking water and have demonstrated that the selenium limits for drinking water can be achieved with specific process designs based on these aluminosilicates [185][186][187].…”

Nanomaterials for elemental speciation

“…The authors declared that the MSPE-HPLC-ICP-MS method is sensitive, fast, easy-to-operate, and economical with unique advantages of low sample consumption consequently suitable for selenium speciation in a small number of seleniumenriched yeast cells. 70 Kim et al 73 has been proposed a simple and quick MSPE technique for the determination of selenite in natural water by using TiO 2 @SiO 2 /Fe 3 O 4 nanoparticles as sorbents. The synthesized nanoparticles were used to separate Se IV in the presence of Se VI or selenium anions for the photocatalytic reduction to elemental Se on the TiO 2 shell.…”

Speciation of trace metals and metalloids by solid phase extraction with spectrometric detection: a critical review

“…80 As an example of mixed oxide sorbent materials TiO 2 @SiO 2 /Fe 3 O 4 nanoparticles were used for the extraction of Se(VI) selectively from natural waters. 81 Inorganic Se speciation was based on the separation of Se(IV) from Se(VI) and organic Se. The separation was carried out by photocatalytic reaction with TiO 2 under UV radiation (6 W) for 3 h. TiO 2 shell of the nanoparticles with UV irradiation causes photocatalytic reduction of Se(VI) and Se(IV) ions to Se(0) atoms.…”