Details

Autor(en) / Beteiligte

• Wang, Jingjing
• Qiang, Shirong
• Wang, Yun
• Wu, Wangsuo
• Li, Ping
• Qin, Haibo
• Fan, Qiaohui

Titel

Adsorption of U(VI) on the natural soil around a very low-level waste repository

Ist Teil von

• Journal of environmental radioactivity, 2021-07, Vol.233, p.106619-106619, Article 106619

Ort / Verlag

England: Elsevier Ltd

Erscheinungsjahr

2021

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• The behaviors of U(VI) in environmental media around radioactive waste disposal site are important for safety assessment of geological repositories. However, the estimation of environmental behaviors of U(VI) in natural media was insufficient. This work aimed to determine the adsorption of U(VI) on natural soil surrounding a candidate very low-level radioactive waste (VLLW) disposal site in southwest China. Results showed that the adsorption process of U(VI) on soils could be well supported by pseudo-second-order kinetic and Freundlich model. The adsorption of U(VI) was pH-dependent but temperature-independent. High ionic strength (NaCl) strongly affected the adsorption process at low pH (2.0–5.5). CO32− remarkably inhibited the U(VI) adsorption, while the adsorption of U(VI) was promoted by PO43− and SO42−. Naturally occurred soil organic matters (SOMs) showed high affinity for U(VI), while the presence of additional humic acid (HA) strongly inhibited U(VI) adsorption. The occurrence of ferrous iron could result in the reduction of U(VI) at low pH values (pH < 4), leading to the promotion of immobilization of U(VI). These findings would provide some guidance for the safety assessments of the VLLW disposal as well as the remediation of contaminated soil. [Display omitted] •Interactions of U(VI) with natural soil were studied.•Soil organic matters strongly complexed with U(VI).•The reduction of U(VI) by Fe(II) was found in natural soil.•The strong complexation and reduction made the adsorption irreversible.