Organophosphorus mineralizing-Streptomyces species underpins uranate immobilization and phosphorus availability in uranium tailings.

Phosphate-solubilizing bacteria (PSB) are important but often overlooked regulators of uranium (U) cycling in soil. However, the impact of PSB on uranate fixation coupled with the decomposition of recalcitrant phosphorus (P) in mining land remains poorly understood. Here, we combined gene amplicon sequencing, metagenome and metatranscriptome sequencing analysis and strain isolation to explore the effects of PSB on the stabilization of uranate and P availability in U mining areas.

Study on uranium leaching from uranium purification residue with ammonium hydrogen fluoride.

Residues generated from the uranium purification process, characterized by a high uranium content, pose a significant challenge for recovery through leaching and present a considerable environmental threat. After using XRD and SEM-mapping characterization analysis combined with the BCR continuous graded extraction test to analyze the content of different states of uranium, it was found that the main reason why the uranium in the residue was difficult to leach because it was encapsulated by SiO crystals. Using NHHF as a leaching agent, a leaching study of uranium in the residue was carried out, and the results showed that the H and F produced by NHHFcould react with SiO, destroying the crystal lattice of SiO and causing the encapsulated uranium to come into contact with the leaching agent, facilitating the leaching of uranium in the residue.

Utilization of nickel-graphite electrode as an electron donor for high-efficient microbial removal of solved U(VI) mediated by Leifsonia sp.

Enzymatically catalyzed reduction of metals by bacteria has potential application value to uranium-mine wastewater. However, its practical implementation has long been restricted by its intrinsic drawbacks such as low efficiency and long treatment-time. This study aims to explore the effect of electrodes on U (VI) removal efficiency by a purified indigenous bacteria isolated from a uranium mining waste pile in China.

Effect of Leifsonia sp. on retardation of uranium in natural soil and its potential mechanisms.

Uranium mining and milling activities for many years resulted in release of uranium into the adjoining soil in varying degrees. Bioremediation approaches (i.e.

Low concentration of Fe(II) to enhance the precipitation of U(VI) under neutral oxygen-rich conditions.

Immobilization of U(VI) by naturally ubiquitous ferrous ions (Fe(II)) has been considered as an efficient and ecofriendly method to retard the migration of aqueous U(VI) at many nuclear sites and surface environments. In this study, we conducted Fe-U coprecipitation experiments to investigate the mechanism and stability of uranium (U) precipitation induced by a small quantity of Fe(II) under oxygen-rich conditions. The experimental results suggest that the sedimentation rates of U(VI) by Fe(II) under neutral oxygen-rich conditions are more than 96%, which are about 36% higher than those without Fe(II) and 16% higher than those under oxygen-free conditions.

Correction to: Influence of Leifsonia sp. on U(VI) removal efficiency and the Fe-U precipitates by zero-valent iron.

The original publication of this paper contains a mistake.

Influence of Leifsonia sp. on U(VI) removal efficiency and the Fe-U precipitates by zero-valent iron.

Zero-valent iron (ZVI) has been widely applied to the remediation of uranium (U)-contaminated water. Notably, indigenous bacteria may possess potential positive or unfavorable influence on the mechanism and stability of Fe-U precipitates. However, the focus of the researches in this field has mainly been on physical and/or chemical aspects.

Influence on Uranium(VI) migration in soil by iron and manganese salts of humic acid: Mechanism and behavior.

Soil contains large amounts of humic acid (HA), iron ions and manganese ions, all of which affect U(VI) migration in the soil. HA interacts with iron and manganese ions to form HA salts (called HA-Fe and HA-Mn in this paper); however, the effects of HA-Fe and HA-Mn on the migration of U(VI) is not fully understood. In this study, HA-Fe and HA-Mn were compounded by HA interactions with ferric chloride hexahydrate and manganese chloride tetrahydrate, respectively.

Understanding the solid phase chemical fractionation of uranium in soil profile near a hydrometallurgical factory.

Uranium (U) contamination of soil has become a major concern with respect to its toxicity, accumulation in the food chain, and persistence in the environment. Anthropogenic activities like mining and processing of U ores has become pressing issues throughout the world. The aim of the work is to understand the chemical fractionation of U in polluted soil and the mechanism involved.

Uranium adsorption and subsequent re-oxidation under aerobic conditions by Leifsonia sp. - Coated biochar as green trapping agent.

It has generally been assumed that the immobilization of U(VI) via polyphosphate accumulating microorganisms may present a sink for uranium, but the potential mechanisms of the process and the stability of precipitated uranium under aerobic conditions remain elusive. This study seeks to explore the mechanism, capacity, and stability of uranium precipitation under aerobic conditions by a purified indigenous bacteria isolated from acidic tailings (pH 6.5) in China.