Highly Efficient Removal of Uranium(VI) from Wastewater by Polyamidoxime/Polyethyleneimine Magnetic Graphene Oxide

Abstract

Highly efficient removal of U­(VI) from mine radioactive wastewater has received a lot of attention. Herein, the polyamidoxime/polyethyleneimine magnetic graphene oxide (mGO-PP) adsorbent was successfully prepared by in situ polymerization of acrylonitrile on magnetic GO (mGO) covalently modified with polyethylenimine (PEI). The mGO-PP was characterized by Fourier transform infrared (FT-IR), scanning electron microscopy, transmission electron microscopy, vibrating sample magnetometer, and X-ray photoelectron spectroscopy (XPS). The maximum adsorption capacity of mGO-PP toward U­(VI) was 606.06 mg/g at 298 K and pH 6.0. The removal of U­(VI) by mGO-PP for U­(VI) was a monolayer chemisorption based on the study of the batch experiment. The calculated thermodynamic parameters indicated that the removal of U­(VI) by mGO-PP was a spontaneous and endothermic process. The adsorption mechanism of mGO-PP toward U­(VI) was explored by FT-IR and XPS analyses. Furthermore, the removal rate of U­(VI) by mGO-PP is 93.68% and the K d value for U­(VI) is 444.73 L/g in actual mine radioactive wastewater, and the residual U­(VI) concentration (6.37 μg/L) in wastewater was lower than the maximum permissible concentration of uranium in drinking water (30 μg/L) (World Health Organization). This indicated that the mGO-PP composite is a promising adsorbent for efficient removal of U­(VI) from practical mine radioactive wastewater.

Bio-functionalized magnetic nanoparticles for cost-effective adsorption of U(vi): experimental and theoretical investigation

“…Various recently-developed materials exhibit high efficiency in U(VI) removal. [9][10][11][12][13][14][15] Nanomaterials are one of the greatest discoveries of all time, with applications in almost every eld. Several NPs have been chosen earlier to remove U(VI) from water.…”

Stimuli-Responsive Ion Adsorbents for Sustainable Separation Applications

“…48,49 Although such chemical-dependent regeneration facilitates good reusability of the IAs, these chemical-intensive regeneration processes are likely to lead to secondary environmental pollution. 50 In the attempt to minimize the use of chemicals in the regeneration processes, a number of functionally responsive molecules have been adopted to synthesize a series of SRIAs that exhibit responsive characteristics to various physical stimuli (Figure 1d), such as thermal-responsive poly(N,N′-dimethylvinyl-benzylamine) 51 (PDMVBA) and poly(N-isopropylacrylamide) 52,53 (PNIPAM); CO 2 -responsive poly(2-dimethylaminoethyl methacrylate) 54 (PDMAEMA) and poly N,N-diethylacrylamide 55 (PDEA), pH-responsive carboxymethyl cellulose 56,57 (CMC), polyitaconic acid, 58 poly(acrylic acid) (PAA), 32 polyamidoxime, 59,60 polyaniline, 58,61 and poly(allylsulfonic acid) 62 (PASA); lightresponsive coumarin, 45 spiropyran (SP), 63 and azobenzene 64 (AZO) molecules; ion-responsive crown ethers (i.e., acryloylamidobenzo-18-crown-6 65 (AmB18C6) and dibenzo-14-crown-4 64 (DB14C4)); and voltage-responsive polypyrrole, 66,67 and GO composites. 68 SRIAs can be classified into nonporous (nanoparticles 69,70 and nanosheets 71 ), nanoporous (mesoporous polymer sphere (MPS), 53 carbon, 72 and silica 73 ), and angstrom-porous (MOFs 51,65 and ion sieves 74 ) materials, which can directly be used as SRIAs.…”

“…To regenerate the IAs, high-concentration chemical solutions of hydrochloric acid (HCl), − sodium hydroxide (NaOH), , sulfuric acid (H 2 SO 4 ), , sodium chloride (NaCl), , ethylenediaminetetraacetic acid (EDTA), , sodium carbonate (Na 2 CO 3 ), , and nitric acid (HNO 3 ), and mixed solutions of HCl–ethanol and HCl–thiourea as eluents have been widely used to desorb the IAs. , Although such chemical-dependent regeneration facilitates good reusability of the IAs, these chemical-intensive regeneration processes are likely to lead to secondary environmental pollution . In the attempt to minimize the use of chemicals in the regeneration processes, a number of functionally responsive molecules have been adopted to synthesize a series of SRIAs that exhibit responsive characteristics to various physical stimuli (Figure d), such as thermal-responsive poly­( N , N ′-dimethylvinyl-benzylamine) (PDMVBA) and poly­( N -isopropylacrylamide) , (PNIPAM); CO 2 -responsive poly­(2-dimethylaminoethyl methacrylate) (PDMAEMA) and poly N , N -diethylacrylamide (PDEA), pH-responsive carboxymethyl cellulose , (CMC), polyitaconic acid, poly­(acrylic acid) (PAA), polyamidoxime, , polyaniline, , and poly­(allylsulfonic acid) (PASA); light-responsive coumarin, spiropyran (SP), and azobenzene (AZO) molecules; ion-responsive crown ethers ( i.e ., acryloylamidobenzo-18-crown-6 (AmB18C6) and dibenzo-14-crown-4 (DB14C4)); and voltage-responsive polypyrrole, , and GO composites …”