在含碳酸氢根的水中生成并稳定方钠石。

Formation and stability of studtite in bicarbonate-containing waters.

机构信息

Department of Chemistry, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal institute of Technology, SE-10044 Stockholm, Sweden.

Department of Fibre and Polymer Technology, Wallenberg Wood Science Center, KTH Royal Institute of Technology, 10044 Stockholm, Sweden.

出版信息

Ecotoxicol Environ Saf. 2023 Sep 15;263:115297. doi: 10.1016/j.ecoenv.2023.115297. Epub 2023 Jul 24.

DOI:10.1016/j.ecoenv.2023.115297

PMID:37494736

Abstract

Studtite and meta-studtite are the only two uranyl peroxides found in nature. Sparsely soluble studtite has been found in natural uranium deposits, on the surface of spent nuclear fuel in contact with water and on core material from major nuclear accidents such as Chernobyl. The formation of studtite on the surface of nuclear fuel can have an impact on the release of radionuclides to the biosphere. In this work, we have experimentally studied the formation of studtite as function of HCO concentration and pH. The results show that studtite can form at pH ≤ 10 in solutions without added HCO. At pH ≤ 7, the precipitate was found to be mainly studtite, while at 8 ≤ pH ≤ 9.8, a mixture of studtite and meta-schoepite was found. Studtite formation from UO and HO was observed at [HCO] ≤ 2 mM and studtite was only found to dissolve at [HCO] > 2 mM.

摘要

天然存在的铀过氧化物只有两种，分别为斜方铀矿和假斜方铀矿。在天然铀矿床、与水接触的乏核燃料表面以及切尔诺贝利等重大核事故的堆芯材料中，都发现了溶解度较低的斜方铀矿。核燃料表面斜方铀矿的形成可能会影响放射性核素向生物圈的释放。在这项工作中，我们通过实验研究了 HCO 浓度和 pH 值对斜方铀矿形成的影响。结果表明，在没有添加 HCO 的溶液中，当 pH ≤ 10 时，斜方铀矿可以形成。在 pH ≤ 7 的情况下，沉淀物主要为斜方铀矿，而在 8 ≤ pH ≤ 9.8 的情况下，则发现斜方铀矿和假斜方铀矿的混合物。在 [HCO] ≤ 2 mM 的条件下观察到 UO 和 HO 生成斜方铀矿的过程，并且仅在 [HCO] > 2 mM 的条件下发现斜方铀矿溶解。