Efficient capture of strontium from aqueous solutions using graphene oxide–hydroxyapatite nanocomposites

Abstract

Three-dimensional hierarchical flower-like graphene oxide-hydroxyapatite (GO-HAp) nanocomposites were synthesized by a simple biomimetic method in a modified simulated body fluid (mSBF). The obtained GO-HAp nanocomposites were characterized by field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transformed infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and N2 adsorption-desorption analysis. The formation mechanism was proposed and the prepared GO-HAp was applied as an adsorbent to remove strontium from large volumes of aqueous solutions. A maximum adsorption capacity of 702.18 mg g(-1) was achieved on GO-HAp, almost two fold higher than that of bare HAp and nine fold higher than that of GO. The effects of pH, adsorbent content, contact time and Sr(2+) initial concentrations on Sr(2+) removal from solution by GO-HAp were systematically investigated, and the results indicated that the removal of Sr(2+) by GO-HAp was weakly dependent on solution pH. The results herein reveal that the GO-HAp nanocomposites had exceptional potential as a suitable material for preconcentration and solidification of radiostrontium from large volumes of aqueous solutions in nuclear waste management and radiostrontium pollution cleanup.

Synthesis and characterization of ultrasound assisted “graphene oxide–magnetite” hybrid, and investigation of its adsorption properties for Sr(II) and Co(II) ions

“…From theoretical standpoint, Fe(OH) 3 and to a lesser extent Fe(OH) 2 are unstable at high temperature (e.g. 95 • C) [31], and tend to be converted to the more thermodynamically stable Fe 3 O 4 by losing of water.…”

“…Among the incoming H 2 O, and OH − ions, some play roles of the bridge between the initial (i.e. sequestered) Fe atoms and the iron atoms of the Fe(OH) 3 and Fe(OH) 2 molecules via hydrogen bonding (step 2). Since at the temperature of reaction (T = 95 • C) the Fe OH OH Fe bridge is unstable [31], it breaks down to a more stable Fe O Fe bond with liberation of water molecules (dehydration step 3).…”

“…One of the most hazardous radioisotopes whose separation from HLW has been subject of a long study is 90 Sr [3,4]. The examined methods for isolation of this isotope include: chemical precipitation of multiple radionuclides.…”

Carbon nanotubes, graphene, and their derivatives for heavy metal removal

“…Wen et al [69] prepared three-dimensional hierarchical flower-like GO-hydroxyapatite (GO-HAp) nanocomposites for Sr(II) removal. The GO was synthesized through a modified Hummers method, and the HAp grew on the GO nanosheets via a biomimetic method.…”

Natural illite as an Efficient Adsorbent for Thorium Removal

“…Radionuclides with high mobility in contaminated water will transfer into soil and plant materials. The radionuclides will enter the food chain, which will potentially produce serious damage to human beings (Wen et aL, 2014). Among these nuclear waste and fission products, one of the elements that cause people to pay attention to is thorium.…”