Sorption of U(VI) compounds on inorganic composites containing partially unzipped multiwalled carbon nanotubes

Unlike ion-exchange resins, inorganic sorbents possess high selectivity towards heavy metal ions and stability against ionizing radiation. However, sorption on these materials is rather slow. Moreover, capacity strongly depends the solution pH. In order to improve properties of ion-exchangers, composites containing advanced carbon are obtained. Regularities U(VI) compounds from low-concentrated aqueous solutions (up 0.1 mmol dm–3 uranium) hydrated zirconium dioxide hydrophosphate considered. The were modified with partially unzipped multiwalled nanotubes (PUMWCNTs). Sorption isotherms obtained analyzed. They obey Dubinin-Radushkevich model indicating sites, a size which comparable that being sorbed. As found, mechanism ion exchange. effect pH rate ion-exchangers their has been Carbon additions increase hydrophosphate, when initial one-component 3–4 5–7 respectively. Under conditions, U(VI)-containing cations removed practically completely. obeys chemical reaction pseudo-second order, uranium solution. PUMWCNTs slow down accelerate it hydrophosphate. dependence pseudo second equation constants was first occurs, contains also Ca2+ Mg2+ ions. Regeneration carried out using HNO3 NaHCO3 solutions: rate-determining stage desorption particle diffusion. It shown ZHP can be regenerated most suitable for ZHP-PUMWCNTs composite 1 M