Geochemical and U-Th isotopic insights on uranium enrichment in reservoir sediments

Jin Wang; Meiling Yin; Juan Liu; Chuan-Chou Shen; Tsai-Luen Yu; Hong-Chun Li; Qiaohui Zhong; Guodong Sheng; Ke Lin; Xiuyang Jiang; Hongliang Dong; Siyu Liu; Tangfu Xiao

doi:10.1016/j.jhazmat.2021.125466

Geochemical and U-Th isotopic insights on uranium enrichment in reservoir sediments

J Hazard Mater. 2021 Jul 15:414:125466. doi: 10.1016/j.jhazmat.2021.125466. Epub 2021 Feb 19.

Authors

Jin Wang¹, Meiling Yin², Juan Liu², Chuan-Chou Shen³, Tsai-Luen Yu⁴, Hong-Chun Li⁵, Qiaohui Zhong², Guodong Sheng⁶, Ke Lin⁵, Xiuyang Jiang⁷, Hongliang Dong⁸, Siyu Liu², Tangfu Xiao²

Affiliations

¹ School of Environmental Science and Engineering, Guangzhou University; Key Laboratory of Water Quality and Conservation in the Pearl River Delta, Ministry of Education, Guangzhou 510006, China; Guangdong Provincial Key Laboratory of Radionuclides Pollution Control and Resources, Guangzhou 510006, China. Electronic address: wangjin@gzhu.edu.cn.
² School of Environmental Science and Engineering, Guangzhou University; Key Laboratory of Water Quality and Conservation in the Pearl River Delta, Ministry of Education, Guangzhou 510006, China.
³ High-Precision Mass Spectrometry and Environment Change Laboratory (HISPEC), Department of Geosciences, National Taiwan University, Taipei 10617, Taiwan; Research Center for Future Earth, National Taiwan University, Taipei 10617, Taiwan.
⁴ High-Precision Mass Spectrometry and Environment Change Laboratory (HISPEC), Department of Geosciences, National Taiwan University, Taipei 10617, Taiwan; Research Center for Future Earth, National Taiwan University, Taipei 10617, Taiwan; Marine Industry and Engineering Research Center, National Academy of Marine Research, Kaohsiung 80661, Taiwan.
⁵ High-Precision Mass Spectrometry and Environment Change Laboratory (HISPEC), Department of Geosciences, National Taiwan University, Taipei 10617, Taiwan.
⁶ College of Chemistry and Chemical Engineering, Shaoxing University, Shaoxing 312000, China.
⁷ Key Laboratory for Humid Subtropical Eco-geographical Process of the Ministry of Education, School of Geographical Sciences, Fujian Normal University, Fuzhou 350007, China.
⁸ Center for High Pressure Science and Technology Advanced Research, Pudong, Shanghai 201203, China; State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 201899, China.

PMID: 33657470
DOI: 10.1016/j.jhazmat.2021.125466

Abstract

Uranium (U) geochemistry and its isotopic compositions of reservoir sediments in U mine area were poorly understood. Herein, U and Th isotopic compositions were employed to investigate source apportionment and geochemical behavior of U in 41 reservoir sediments from a U mining area, Guangdong, China. The remarkably high contents of both total U (207.3-1117.7 mg/kg) and acid-leachable U (90.3-638.5 mg/kg) in the sediments exhibit a severe U contamination and mobilization-release risk. The U/Th activity ratios (ARs) indicate that all sediments have been contaminated apparently by U as a result of discharge of U containing wastewater, especially uranium mill tailings (UMT) leachate, while the variations of U/Th ARs are dominated by U geochemical behaviors (mainly redox process and adsorption). The U isotopic compositions (δ²³⁸U) showed a large variance through the sediment profile, varying from - 0.62 to - 0.04‰. The relation between δ²³⁸U and acid-leachable U fraction demonstrates that the U isotopic fractionation in sediments can be controlled by bedrock weathering (natural activity), UMT leachate (anthropogenic activity) and subsequent biogeochemical processes. The findings suggest that U-Th isotopes are a powerful tool to better understand U geochemical processes and enrichment mechanism in sediments that were affected by combined sources and driving forces.

Keywords: Enrichment mechanism; Reservoir sediments; Uranium; Uranium mill tailings; Uranium-thorium isotopes.

Publication types

Research Support, Non-U.S. Gov't