Spectroscopic and modeling investigation of U(VI) removal mechanism on nanoscale zero-valent iron/clay composites

The Removal Mechanism of U(VI) on nZVI/MoS2 Composites Investigated by Batch, Spectroscopic, and Modeling Techniques

“…The adsorption of U­(VI) on MoS 2 and nZVI/MoS 2 gradually increased with the increase of pH from 2.0 to 6.0 and reached the highest removal at pH 6.0–9.0 (92 and 95.0% for MoS 2 and nZVI/MoS 2 , respectively). However, the decreased removal of U­(VI) at pH >10 was observed, which was similar to previous studies. − The pH-dependent removal of U­(VI) on nZVI/MoS 2 can be interpreted by the electrostatic interaction between U­(VI) and adsorbents. The low adsorption of U­(VI) on nZVI/MoS 2 and MoS 2 at low pH could be due to the electrostatic repulsion of positively charged adsorbents and positive UO 2 2+ , while the decreased adsorption of U­(VI) at high pH can also be interpreted by electrostatic repulsion of negatively charged adsorbents and negative U­(VI) species such as UO 2 (CO 3 ) 2 2– and UO 2 (CO 3 ) 3 4– species.…”

Enhanced photocatalytic removal of U(vi) from water using tea waste biochar/g-C3N4/MoS2 Z-scheme composite: synthesis, performance, and mechanistic insights

“…39 Among them, the addition of CO 3 2− decreased the removal efficiency of U( vi ) by approximately 19%, which may be related to the increase in the solution pH due to the addition of CO 3 . 2–40 To summarize, the coexisting metal ions and anions have a minor impact on the photoreduction of U( vi ), even when their concentration is 10 times higher than that of U( vi ), indicating little effect on the removal efficiency of U( vi ). Therefore, it is confirmed that 10%BgM has high anti-interference ability for the removal of U( vi ).…”

“…3,4 Various methods have been developed to remove U(VI) from water, including adsorption, membrane filtration, chemical reduction, and photocatalysis. 5,6 Adsorption has become a widely employed method for U(VI) removal from wastewater owing to its simplicity, ease of preparation, and low energy consumption. 7 However, the adsorption capacity of adsorbents is limited by the number of active sites, which can become blocked when U(VI) is adsorbed onto the surface.…”

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

“…Figure 5 shows the regeneration of U(VI), Pb(II), and HA on MoS 2 and The lack of significant changes in XRD patterns of nZVI/MoS 2 after reaction at pH 4.0 indicated the chemical stability under acidic conditions. 35 Figure 6B shows the FTIR spectra of nZVI/MoS 2 composites after removing targeted pollutants. Notably, the presence of U = O (550 cm −1 ) and U−O groups (710 cm −1 ) indicated uranium adsorption on nZVI/MoS 2.…”