The existence state and spatiotemporal evolution process of uranium in mineral-microbe complex systems are important factors that constrain its ecotoxicity. This study investigated the sequestration of U(VI) by montmorillonite-Aspergillus niger (MTA) composite using bioassay and spectroscopies approaches. The results demonstrate that the sequestration process and mechanism of U(VI) on MTA differ substantially from those of individual components. Under neutral conditions, the sorption of U(VI) decreased from 92.4 ± 4.6 % on MT to 73.2 ± 2.4 % on MTA4 and 74.9 ± 6.3 % on MTA10, respectively, while the stability of U(VI) species on MTA increased obviously compared to MT. In the case of MTA formed over 4 days (MTA4), the biosorption effect of A. niger hyphae dominated the sequestration of U(VI). In contrast, for MTA formed over 10 days (MTA10), the interactions between MT and A. niger became more pronounced, and the hyphae of Aspergillus niger played a pivotal role in U(VI) sequestration, immobilizing U(VI) through complexation with organic ligands and bioreduction reactions. The high expandability of MT facilitated the penetration of extracellular polymeric substances (EPS) from A. niger into its interlayer of MT, enhancing U(VI) complexation and reduction. These processes significantly contributed to the effective sequestration of U(VI) by the MTA composite.
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http://dx.doi.org/10.1016/j.scitotenv.2024.177952 | DOI Listing |
Sci Total Environ
December 2024
Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; Key Laboratory of Petroleum Resources Exploration and Evaluation, Gansu Province, Lanzhou 730000, China; Key Laboratory of Strategic Mineral Resources of the Upper Yellow River, Ministry of Natural Resources, Lanzhou 730046, China. Electronic address:
The existence state and spatiotemporal evolution process of uranium in mineral-microbe complex systems are important factors that constrain its ecotoxicity. This study investigated the sequestration of U(VI) by montmorillonite-Aspergillus niger (MTA) composite using bioassay and spectroscopies approaches. The results demonstrate that the sequestration process and mechanism of U(VI) on MTA differ substantially from those of individual components.
View Article and Find Full Text PDFInt J Pharm
September 2024
State Key Laboratory of Trauma and Chemical Poisoning, Institute of Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Army Medical University, Chongqing 400038, China. Electronic address:
The combined chemotoxicity and radiotoxicity associated with uranium, utilized in nuclear industry and military applications, poses significant threats to human health. Among uranium pollutants, uranyl is particularly concerning due to its high absorptivity and potent nephrotoxicity in its + 6 valence state. Here, we have serendipitously found NaSeO facilitates the conversion of U(VI) to U(IV) precipitates.
View Article and Find Full Text PDFWater Res
August 2024
School of Nuclear Science and Engineering, East China University of Technology, Nanchang 330013, PR China. Electronic address:
Numerous investigations have illuminated the profound impact of phosphate on the adsorption of uranium, however, the effect of phosphate-mediated surface modification on the reactivity of zero-valent iron (ZVI) remained enigmatic. In this study, a phosphate-modified ZVI (P-ZVI) was prepared with a facile ball milling strategy, and compared with ZVI, the U(VI) removal amount (435.2 mg/g) and efficiency (3.
View Article and Find Full Text PDFEnviron Pollut
September 2024
Research Center of Radiation Ecology and Ion Beam Biotechnology, College of Physics Science and Technology, Xinjiang University, Urumqi, Xinjiang, 830017, PR China.
Prokaryotes are effective biosorbents for the recovery of uranium and other heavy metals. However, the potential mechanism of uranium bioaccumulation by filamentous strain (actinobacteria) remains unclear. This study demonstrates the potential for and mechanism of uranium bioaccumulation by living (L-SS) and inactivated (I-SS) Streptomyces sp.
View Article and Find Full Text PDFChemosphere
November 2023
School of Resource & Environment and Safety Engineering, University of South China, Hengyang, Hunan, 421001, PR China.
The dynamic reactions of uranium (U) with iron (Fe) minerals change its behaviors in soil environment, however, how the coexisted constituents in soil affect U sequestration and release on Fe minerals during the transformation remains unclear. Herein, coupled effects of lead (Pb) and dissolved organic matter (DOM) on U speciation and release kinetics during the catalytic transformations of ferrihydrite (Fh) by Fe(II) were investigated. Our results revealed that the coexistence of Pb and DOM significantly reduced U release and increased the immobilization of U during Fh transformation, which were attributed to the enhanced inhibition of Fh transformation, the declined release of DOM and the increased U(VI) reduction.
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