Arsenic triggered nano-sized uranyl arsenate precipitation on the surface of Kocuria rosea

Lei Zhou; Faqin Dong; Xiangyu Xi; Lin Zhou; Qunwei Dai; Mingxue Liu; Ying Han; Gang Yang; Yongde Zhang

doi:10.1016/j.jenvrad.2023.107168

Arsenic triggered nano-sized uranyl arsenate precipitation on the surface of Kocuria rosea

J Environ Radioact. 2023 Jun:262:107168. doi: 10.1016/j.jenvrad.2023.107168. Epub 2023 Mar 30.

Authors

Lei Zhou¹, Faqin Dong², Xiangyu Xi³, Lin Zhou⁴, Qunwei Dai⁵, Mingxue Liu³, Ying Han³, Gang Yang³, Yongde Zhang⁵

Affiliations

¹ Fundamental Science on Nuclear Wastes and Environmental Safety Laboratory, Southwest University of Science and Technology, Mianyang, Sichuan, 621010, China; School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang, Sichuan, 621010, China.
² School of Environment and Resource, Southwest University of Science and Technology, Mianyang, Sichuan, 621010, China; Key Laboratory of Solid Waste Treatment and the Resource Recycle, Southwest University of Science and Technology, Mianyang, Sichuan, 621010, China. Electronic address: fqdong@swust.edu.cn.
³ School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang, Sichuan, 621010, China.
⁴ School of Environment and Resource, Southwest University of Science and Technology, Mianyang, Sichuan, 621010, China; Key Laboratory of Solid Waste Treatment and the Resource Recycle, Southwest University of Science and Technology, Mianyang, Sichuan, 621010, China.
⁵ Fundamental Science on Nuclear Wastes and Environmental Safety Laboratory, Southwest University of Science and Technology, Mianyang, Sichuan, 621010, China.

PMID: 37003252
DOI: 10.1016/j.jenvrad.2023.107168

Abstract

Arsenic (As) and uranium (U) frequently occur together naturally and, in consequence, transform into cocontaminants at sites of uranium mining and processing, yet the simultaneous interaction process of arsenic and uranium has not been well documented. In the present contribution, the influence of arsenate on the removal and reduction of uranyl by the indigenous microorganism Kocuria rosea was characterized using batch experiments combined with species distribution calculation, SEM-EDS, FTIR, XRD and XPS. The results showed that the coexistence of arsenic plays an active role in Kocuria rosea growth and the removal of uranium under neutral and slightly acidic conditions. U-As complex species of UO₂HAsO₄ (aq) had a positive effect on uranium removal, while Kocuria rosea cells appeared to have a large specific surface area serving as attachment sites. Furthermore, a large number of nano-sized flaky precipitates, constituted by uranium and arsenic, attached to the surface of Kocuria rosea cells at pH 5 through P=O, COO^-, and C=O groups in phospholipids, polysaccharides, and proteins. The biological reduction of U(VI) and As(V) took place in a successive way, and the formation of a chadwickite-like uranyl arsenate precipitate further inhibited U(VI) reduction. The results will help to design more effective bioremediation strategies for arsenic-uranium cocontamination.

Keywords: Arsenic; Kocuria rosea; Successive reduction; Uranium; Uranyl arsenate precipitate.

MeSH terms

Arsenates / chemistry
Arsenic*
Radiation Monitoring*
Uranium* / metabolism

Substances

Arsenic
arsenic acid
Arsenates
Uranium

Supplementary concepts

Kocuria rosea