Removing uranium (VI) from aqueous solution with insoluble humic acid derived from leonardite

Fande Meng; Guodong Yuan; Steven L Larson; John H Ballard; Charles A Waggoner; Zikri Arslan; Fengxiang X Han

doi:10.1016/j.jenvrad.2017.09.019

Removing uranium (VI) from aqueous solution with insoluble humic acid derived from leonardite

J Environ Radioact. 2017 Dec:180:1-8. doi: 10.1016/j.jenvrad.2017.09.019. Epub 2017 Sep 29.

Authors

Fande Meng¹, Guodong Yuan², Steven L Larson³, John H Ballard³, Charles A Waggoner⁴, Zikri Arslan⁵, Fengxiang X Han⁶

Affiliations

¹ Department of Chemistry and Biochemistry, Jackson State University, 1400 J. R. Lynch Street, P.O. Box 17910, Jackson, MS 39217, USA; Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research (YIC), Chinese Academy of Sciences (CAS), Shandong Provincial Key Laboratory of Coastal Environmental Processes, YICCAS, Yantai, Shandong 264003, China; University of Chinese Academy of Sciences, Beijing 100049, China.
² Zhaoqing University, Zhaoqing, Guangdong 526061, China.
³ U.S. Army Engineer Research and Development Center, 3909 Halls Ferry Rd., Vicksburg, MS 39180-6199, USA.
⁴ Institute for Clean Energy Technology, Mississippi State University, 205 Research Blvd, Starkville, MS 39759, USA.
⁵ Department of Chemistry and Biochemistry, Jackson State University, 1400 J. R. Lynch Street, P.O. Box 17910, Jackson, MS 39217, USA.
⁶ Department of Chemistry and Biochemistry, Jackson State University, 1400 J. R. Lynch Street, P.O. Box 17910, Jackson, MS 39217, USA. Electronic address: Fengxiang.han@jsums.edu.

PMID: 28968541
DOI: 10.1016/j.jenvrad.2017.09.019

Abstract

The occurrence of uranium (U) and depleted uranium (DU)-contaminated wastes from anthropogenic activities is an important environmental problem. Insoluble humic acid derived from leonardite (L-HA) was investigated as a potential adsorbent for immobilizing U in the environment. The effect of initial pH, contact time, U concentration, and temperature on U(VI) adsorption onto L-HA was assessed. The U(VI) adsorption was pH-dependent and achieved equilibrium in 2 h. It could be well described with pseudo-second-order model, indicating that U(VI) adsorption onto L-HA involved chemisorption. The U(VI) adsorption mass increased with increasing temperature with maximum adsorption capacities of 91, 112 and 120 mg g^-1 at 298, 308 and 318 K, respectively. The adsorption reaction was spontaneous and endothermic. We explored the processes of U(VI) desorption from the L-HA-U complex through batch desorption experiments in 1 mM NaNO₃ and in artificial seawater. The desorption process could be well described by pseudo-first-order model and reached equilibrium in 3 h. L-HA possessed a high propensity to adsorb U(VI). Once adsorbed, the release of U(VI) from L-HA-U complex was minimal in both 1 mM NaNO₃and artificial seawater (0.06% and 0.40%, respectively). Being abundant, inexpensive, and safe, L-HA has good potential for use as a U adsorbent from aqueous solution or immobilizing U in soils.

Keywords: Artificial seawater; Depleted uranium; Desorption; Humic acid; Leonardite; Soil; Uranium contamination.

MeSH terms

Adsorption
Humic Substances*
Kinetics
Minerals / chemistry*
Models, Chemical*
Soil
Uranium / analysis
Uranium / chemistry*
Water Pollutants, Radioactive / analysis
Water Pollutants, Radioactive / chemistry*

Substances

Humic Substances
Minerals
Soil
Water Pollutants, Radioactive
leonardite
Uranium