Ternary surface complexation promotes simultaneous removal of arsenic and uranium by TiO2

• 成果类型: Article
• 署名作者: Lin, Leiming; Li, Zheng; Ren, Jun; Meng, Ying; Luan, Fubo
• 署名单位: Chinese Academy of Sciences; Research Center for Eco-Environmental Sciences (RCEES), CAS; Chinese Academy of Sciences; University of Chinese Academy of Sciences, CAS; North University of China
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-14794
• DOI: 10.1073/pnas.2501354122
• 发表日期: 2025-03-25
• 关键词: u(vi) sorption; adsorption; water; groundwater; BEHAVIOR; facets; basin

摘要

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}-TiO2. Surprisingly, the presence of U(VI) greatly enhanced the adsorption of As(V) on {001}-TiO2, 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}-TiO2. This ternary surface complex formed through the substitution of CO32-from uranyl coordination sites. Furthermore, the adsorbed As(V) and U(VI) can be easily recovered using a sodium hydroxide solution, and {001}-TiO2 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.