Uranium re-adsorption on uranium mill tailings and environmental implications

Meiling Yin; Jing Sun; Hongping He; Juan Liu; Qiaohui Zhong; Qingyi Zeng; Xianfeng Huang; Jin Wang; Yingjuan Wu; Diyun Chen

doi:10.1016/j.jhazmat.2021.126153

Uranium re-adsorption on uranium mill tailings and environmental implications

J Hazard Mater. 2021 Aug 15:416:126153. doi: 10.1016/j.jhazmat.2021.126153. Epub 2021 May 18.

Authors

Meiling Yin¹, Jing Sun², Hongping He³, Juan Liu⁴, Qiaohui Zhong⁴, Qingyi Zeng⁵, Xianfeng Huang⁶, Jin Wang⁷, Yingjuan Wu⁴, Diyun Chen⁸

Affiliations

¹ Key Laboratory of Water Quality and Conservation in the Pearl River Delta, Ministry of Education, School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, China; School of Environment and Energy, South China University of Technology, Guangzhou 510006, China.
² State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China.
³ Guangdong Provincial Key Laboratory of Mineral Physics and Materials, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.
⁴ Key Laboratory of Water Quality and Conservation in the Pearl River Delta, Ministry of Education, School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, China.
⁵ School of Resource Environment and Safety Engineering, University of South China, Hengyang 421001, China.
⁶ School of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China.
⁷ Key Laboratory of Water Quality and Conservation in the Pearl River Delta, Ministry of Education, School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, China; Guangdong Provincial Key Laboratory of Radionuclides Pollution Control and Resources, Guangzhou 510006, China. Electronic address: wangjin@gzhu.edu.cn.
⁸ Key Laboratory of Water Quality and Conservation in the Pearl River Delta, Ministry of Education, School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, China; Guangdong Provincial Key Laboratory of Radionuclides Pollution Control and Resources, Guangzhou 510006, China.

PMID: 34492934
DOI: 10.1016/j.jhazmat.2021.126153

Abstract

Uranium mill tailings (UMTs) are one critical source of environmental U pollution. Leaching test has been extensively used to reveal U release capacity and mechanism from UMTs, while little attention has been paid to the effects of re-adsorption process on U release. In this study, the role of U re-adsorption behaviors during leaching test with UMTs was comprehensively investigated. Through paired data on mineralogical composition and aqueous U speciation, the influence of environmentally relevant factors on U re-absorption capacity and mechanism on UMTs with different particle sizes was revealed. Significant amounts of U re-adsorption were observed and primarily attributed to the adsorption on chlorite, albite and muscovite as well as combined reduction-sequestration by muscovite. Uranium re-adsorption predominantly occurred via inner-sphere complexation and surface precipitation depending on leachant pH. Coexisting sulfate or phosphate could further enhance U re-adsorption. The enhanced re-adsorption from sulfate occurred when inner-sphere complexation governed the re-adsorption process. These findings suggest that the environmental hazards and ecological risks of the U containing (waste) solids might have been underestimated due to the ignorance of the re-adsorption process, since the re-adsorbed U could be easily re-mobilized. The insights from this study are also helpful in developing effective in-situ remediation strategies.

Keywords: Re-adsorption mechanism; Remediation indication; Solid wastes; Uranium; Waste management.

Publication types

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

MeSH terms

Adsorption
Particle Size
Soil Pollutants, Radioactive*
Uranium* / analysis
Water Pollutants, Radioactive* / analysis

Substances

Soil Pollutants, Radioactive
Water Pollutants, Radioactive
Uranium