Ternary surface complexation promotes simultaneous removal of arsenic and uranium by TiO<sub>2</sub>.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 40112104.
- Also identified by DOI 10.1073/pnas.2501354122 and PMC identifier 11962437.
- Licence recorded as CC BY-NC-ND.
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Abstract
The co-occurrence of arsenic and uranium in groundwater has been found in many countries, posing a significant challenge to human health. Here, we have demonstrated the efficient simultaneous removal of arsenic and uranyl-carbonate complexes from groundwater using {001}-TiO<sub>2</sub>. Surprisingly, the presence of U(VI) greatly enhanced the adsorption of As(V) on {001}-TiO<sub>2</sub>, while As(V) had a negligible impact on U(VI) adsorption. Through in situ ATR-FTIR spectroscopy, we uncovered a mechanism involving the formation of a ternary surface complex [Ti-U(VI)-As(V)] on the surface of {001}-TiO<sub>2</sub>. This ternary surface complex formed through the substitution of CO<sub>3</sub><sup>2-</sup> from uranyl coordination sites. Furthermore, the adsorbed As(V) and U(VI) can be easily recovered using a sodium hydroxide solution, and {001}-TiO<sub>2</sub> can be used repeatedly. Our findings offer a promising solution for the simultaneous removal of As(V) and U(VI) from groundwater and provide valuable insights into the mechanisms involved in their removal.