The Stability of U(VI) and As(V) under the Influence of pH and Inorganic Ligands

Qingshan Tian, Peng Wang, Yunxiang Huang (), Bo Zhang () and Wentao Jiao
Additional contact information
Qingshan Tian: College of Resources and Environment, Hunan Agricultural University, Changsha 410128, China
Peng Wang: China Haohua North Chem, No. 19 Xiaoying Road, Chaoyang District, Beijing 100101, China
Yunxiang Huang: College of Resources and Environment, Hunan Agricultural University, Changsha 410128, China
Bo Zhang: Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, No. 18 Shuangqing Road, Haidian District, Beijing 100085, China
Wentao Jiao: Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, No. 18 Shuangqing Road, Haidian District, Beijing 100085, China

Sustainability, 2022, vol. 14, issue 20, 1-9

Abstract: Uranium and arsenic are two pollutants commonly found in groundwater near uranium mines. However, the reactivity of U(VI) and As(V) need to be carefully investigated to better understand their fate and transport in the environment. In this study, the reactivity of U(VI) and As(V) were studied under various pH, bicarbonate, and Ca 2+ levels. In air-equilibrated systems, the reactivity of U(VI) and As(V) generally decreased with the increase in pH, as evidenced by the solubility of U(VI) and As(V) increasing along with the elevation of pH. At pH = 8, 44.70% and 37.81% of initially added U(VI) and As(V) remained soluble. The addition of 1 mM of bicarbonate increased the reactivity of U(VI) and As(V) at mild acidic to neutral pH; however, the presence of bicarbonate significantly increased the solubility of U(VI) at mild alkaline condition, as nearly all U(VI) remained soluble at pH values of 8 and 9. After the addition of Ca 2+ , the solubility of both U(VI) and As(V) decreased at mild acidic to neutral pH ranges; however, the addition of Ca 2+ markedly increased the soluble percentages of U(VI) at neutral pH, in which the condition 97.81 ± 2.95% of U(VI) remained soluble. Comparatively, only 36.13 ± 4.98% and 1.69 ± 1.08% of U(VI) were soluble at the same pH in air-equilibrated and bicarbonate systems. Our study demonstrated that U(VI) and As(V) are less reactive at neutral to alkaline conditions. Furthermore, the addition of bicarbonate and Ca 2+ can further reduce the reactivity of U(VI) and As(V) at neutral to alkaline conditions. The findings of this study contribute to a deeper understanding of the fate and transport of U(VI) and As(V) in groundwater and could aid in better designing of U(VI) and As(V) removal processes.

Keywords: groundwater; heavy metal; precipitation; phreeqc; water chemistry (search for similar items in EconPapers)
JEL-codes: O13 Q Q0 Q2 Q3 Q5 Q56 (search for similar items in EconPapers)
Date: 2022
References: View complete reference list from CitEc
Citations:

Downloads: (external link)
https://www.mdpi.com/2071-1050/14/20/12967/pdf (application/pdf)
https://www.mdpi.com/2071-1050/14/20/12967/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jsusta:v:14:y:2022:i:20:p:12967-:d:939012

Access Statistics for this article

Sustainability is currently edited by Ms. Alexandra Wu

More articles in Sustainability from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().