Removal of uranium(VI) from aqueous solution using nanoscale zero-valent iron supported on activated charcoal

Abstract

The nanoscale zero-valent iron supported on activated charcoal (nZVI/AC) by the reduction of ferrous sulfate heptahydrate with sodium borohydride was synthesized for uranium(VI) adsorption. The nZVI/AC was characterized using X-ray radiation diffraction and scanning electron microscope. The adsorption kinetics, adsorption isotherms and adsorption thermodynamics were also examined. The adsorption capacity reached 492.6 mg/ g when dosage was 0.5 g/L, initial concentration of uranium(VI) was 250 mg/L, pH was 5, temperature was 35°C and time was 60 min. The experimental results indicated that nZVI/AC possessed many advantages such as simple and economy for preparation, less adsorbent dosage, short balance time, high adsorption ratio and adsorption capacity. The synthesized adsorbent is promising to efficiently treat the uranium-contained wastewater.

Pb(II) Removal from Aqueous Solutions by Adsorption on Stabilized Zero-Valent Iron Nanoparticles—A Green Approach

“…As a means of overcoming these disadvantages, the idea of immobilizing the ZVFe NPs into porous host materials was proposed and discussed in several research studies. Three main categories of porous host materials are available for the stabilization of iron NPs: (i) natural minerals, namely pillared clay [18], pumice granular [19,20], acid activated sepiolites [21,22], montmorillonite [23,24], kaolin [25], bentonite [26,27], zeolite [28][29][30], biochar [31,32], and charcoal [33]; (ii) biomaterials such as pine cone [34], aquatic plant Azolla filiculoides [35], cellulose nanofibrils [36], walnut shell [37], and macroporous alginate ( [38,39]); and (iii) synthetic materials such as cationic resin [40], anion exchange resin [41], porous carbon sheet [42], chelating resin [43], titanate nanotube [44], meso-porous silica carbon [45], layered double hydroxide [46,47], activated carbon [34,48,49], graphene oxide [45,50], chitosan [51], carbon nanotube [52], magnesium (hydr)oxide [19,53], and humic acid [54].…”

Cost-effective core@shell structured zero-valent iron nanoparticles @ magnetic (nZVI@Fe3O4) for Cr(vi) removal from aqueous solutions: preparation by disproportionation of Fe(ii)

“…The increase in reaction temperature results in higher removal efficiency, suggesting an exothermic adsorption process. 45 On the one hand, the warming of the solution (<333.15 K) intensifies the diffusion of oxygen, leading to accelerated corrosion of nZVI@Fe 3 O 4 and the creation of a larger surface area, which allows for more contact between active sites and Cr( vi ), resulting in an increase in removal efficiency. In another light, an increase in temperature facilitates the movement of Cr( vi ) from the solution to the nZVI@Fe 3 O 4 , as more molecules become activated and diffusion is enhanced, which increases the accessibility of active sites on the surface of nZVI@Fe 3 O 4 .…”

Synergistic Removal of U (VI), Pb(II), and HA on nZVI/MoS2 Composites Investigated by Batch, Spectroscopic, and Modeling Techniques

“…Nano-zerovalent iron (nZVI) as a versatile and green material has been extensively introduced into the treatment of various contaminants (e.g., organics, radionuclides, and heavy metals) from agricultural and industrial wastewater due to its small particle size, large surface area, excellent chemical reactivity, abundant surface sites, and strong redox. − However, the tight agglomeration of nZVI and the rapid production of iron corrosion limit its application. , Interestingly, the unique dispersion of nZVI on various supports has been specifically designed with superior removal capacity and ease of separation. − So far, nZVI-based composites (e.g., metal (hydr)­oxides, chitosan/biopolymer, clay, , and carbon-bearing materials − ) as environmentally friendly and effective adsorbents have been extensively employed to remove U­(VI), Pb­(II), and HA from wastewater in different conditions. Among nZVI-based materials, nZVI/MoS 2 exhibited a high adsorption performance, fast adsorption efficiency, and strong redox due to the exposure of unsaturated S in MoS 2 (2D hexagonal transition metal dichalcogenide). ,,− To the authors’ knowledge, the simultaneous removal of Pb­(II), U­(VI), and HA on nZVI/MoS 2 composites in a complicated system is not available.…”