Journal Article
Proceedings of the National Academy of Sciences, vol. 114, iss. 4, pp. 711-716, 2017
Authors
Sharon E. Bone, James J. Dynes, John Cliff, John R. Bargar
Abstract
Significance
Uranium is an important fuel source and pollutant, and its chemical form determines its reactivity in the environment. However, information on the speciation of tetravalent U [U(IV)] in sediments is lacking. The research presented herein takes a holistic view of U(IV) speciation in a natural material containing microbial cells, organic matter, and minerals. Our work demonstrates unequivocally that U(IV) adsorbs to natural organic matter under anoxic, field-relevant conditions. Furthermore, we put forward a conceptual model that provides a framework for future studies of U biogeochemistry in which postreduction surface complexation processes can be used to predict U(IV) behavior. Our work has ramifications for remediation of U-contaminated sites and also informs in situ mining practices.
