Fabrication of magnetic functionalised calix[4]arene composite for highly efficient and selective adsorption towards uranium(VI)

Abstract

Environmental contextUranium-containing wastewaters have high potential to harm the environment and human health. We found that the combination of calix[4]arene with magnetic Fe3O4 particles produced good adsorption of uranium from wastewater. In addition, this material can be recycled and reused, so it has good prospects in practical applications for uranium remediation. AbstractA magnetic functionalised calix[4]arene composite consisting of Fe3O4 and calix[4]arene phosphonate derivative (CPD) was prepared through a facile self-assembly method. The composite was characterised by scanning electron microscopy (SEM), powder X-ray diffraction (PXRD) and Fourier transform infrared spectroscopy (FTIR). The as-synthesised Fe3O4/CPD composite was used to remove UVI from aqueous solutions under different conditions. Meanwhile, the adsorption isotherm, kinetics and thermodynamics were fitted and analysed. The results show that the Fe3O4/CPD composite may be a promising adsorption material for the separation and enrichment of UVI from aqueous solutions in the cleanup of environmental pollution.

Enhancement of Uranium Recycling from Tailings Caused by the Microwave Irradiation-Induced Composite Oxidation of the Fe–Mn Binary System

“…The peaks at wavenumbers of about 470, 537, 698, 779, 789, 914, 944, 1034, 1092, 1304, 1626, 3622, and 3697 cm –1 were observed in the spectrum curve of the raw U tailing sample. The peak at 779 cm –1 was directly attributed to the existence of (UO 2 ) 2+ stretching vibration in the mineral constitution, ,, which was further proved by the XRD pattern of the raw uranium tailing sample (Figure S2, SI). The bands at 470, 1304, 1626, 3622, and 3697 cm –1 had barely changed after different leaching experiments, which were directly assigned to the gangue or inert constituents contained in the mineral, such as Si–O–Si bending vibration and Si–O and P–O symmetric and asymmetric stretching. − The band at 1083 cm –1 in the spectrum of the mixture specimen was ascribed to SO 2 asymmetric and symmetric stretching, which verified the addition of ferric sulfate to the tailing particles. − After MW irradiation, the raw band at 537 cm –1 was shifted left to the band at 516 cm –1 , which reflected the transformation of crystalline silicate to the partial amorphous phase. − The emergence of the peak at 516 cm –1 for the specimen obtained from the sulfuric leaching revealed the substitution of Al 3+ in the octahedral lattice by H + ions.…”

“…The peaks at wavenumbers of about 470, 537, 698, 779, 789, 914, 944, 1034, 1092, 1304, 1626, 3622, and 3697 cm –1 were observed in the spectrum curve of the raw U tailing sample. The peak at 779 cm –1 was directly attributed to the existence of (UO 2 ) 2+ stretching vibration in the mineral constitution, 29 , 67 , 68 which was further proved by the XRD pattern of the raw uranium tailing sample ( Figure S2 , SI). The bands at 470, 1304, 1626, 3622, and 3697 cm –1 had barely changed after different leaching experiments, which were directly assigned to the gangue or inert constituents contained in the mineral, such as Si–O–Si bending vibration and Si–O and P–O symmetric and asymmetric stretching.…”

Colorimetric sensing for the sensitive detection of UO22+via the phosphorylation functionalized mesoporous silica-based controlled release system

“…6 However, when uranium-containing wastewater is discharged and enters the environment exceeding the national discharge standard (0.05 mg L −1 ), it will not only pollute the soil and water but also can enter the human body via food chains and cause harm. 7–10 The US Environmental Protection Agency (EPA) clearly stipulates that the maximum pollution level of UO 2 2+ in drinking water is 130 nmol L −1 . 11 Studies have shown that the accidental ingestion of excessive doses of uranium compounds can cause irreversible radiation damage to the heart, 12 kidneys, 13 brain, 14 and other organs.…”

Efficient removal of pharmaceuticals from water using graphene nanoplatelets as adsorbent

“…There are various removal methods that are used to remove pollutants from water such as bioreactors [ 14 ], degradation and photodegradation [ 15 – 18 ], filtration [ 19 ], photocatalysis [ 20 , 21 ], photo-Fenton and Fenton-like [ 22 , 23 ], coagulation [ 24 ] and adsorption [ 25 , 26 ]. Among these methods, adsorption is a widely used and most efficient method for wastewater treatment.…”