High‑arsenic (As) sinter deposited from geothermal water is a potentially overlooked hazardous matrix and there remain substantial gaps in our comprehension of the stability of As sequestered within it. In this study, qualitative and quantitative analysis of the mineralogy of As-bearing sinter was conducted by Mineral Liberation Analyzer (MLA) in geothermal areas of the Tibetan Plateau to reveal the geochemical stability of As. Our results indicated that the contents of As in sinter were 3 orders of magnitude higher than the local soil. The dominant host minerals of As were calcite (40.9 %), thenardite (22.5 %), calcium silicate (13.0 %), and halite (8.1 %). Additionally, it was found that a relatively higher As bioavailability was extracted by ethylene diamine tetraacetic acid (EDTA), with a leaching rate of 41.2 %. Notably, the X-ray diffraction (XRD) showed that the thenardite and halite were decomposed after the leaching. The combination of mineralogy and geochemistry data suggested that calcite and calcium silicate were a crucial mechanism for As retention in sinter, while the dissolution of saline minerals (e.g., thenardite, halite, and calcium chloride) served as the primary sources for As release. This finding unveils the potential risks and mechanisms associated with high-As sinter, providing scientific guidance for risk management of sinter.
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http://dx.doi.org/10.1016/j.scitotenv.2023.166862 | DOI Listing |
Environ Res
December 2024
College of Land Science and Technology, China Agricultural University, Beijing, 100193, PR China; Key Laboratory of Arable Land Conservation in North China, Ministry of Agriculture and Rural Affairs, Beijing, 100193, PR China. Electronic address:
The ongoing weathering of metal sulfides has substantially posed threats to the eco-systems. For remediating metal sulfides-contaminated soils, phytostabilization is a promising nature-based technique that immobilizing heavy metals (HMs) that dissolved from metal sulfides in the rhizosphere, preventing their leaching and migrating into soil and groundwater. However, the underlying mechanism regarding the mineral-root interaction involving primary metal sulfides such as galena (PbS) during the remediation processes has yet been well studied.
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December 2024
Institut de Chimie Séparative de Marcoule, CEA, UMR 5257 CEA-CNRS-UM-ENSCM, 30207 Bagnols-sur-Cèze, France. Electronic address:
The formation of U(VI) intrinsic colloids has a non-negligible impact on the dissemination of actinides in the environment. It is therefore essential to better identify their nature, formation conditions, and stability domains. These specific points are especially important since the behavior of these elements in environment is generally estimated by geochemical transport modeling.
View Article and Find Full Text PDFBioelectrochemistry
December 2024
School of Bioengineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353 Shandong, PR China; State Key Laboratory of Bio-based Materials and Green Papermaking, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, Shandong, PR China. Electronic address:
Sediment microbial fuel cell (SMFC) is a device for biological denitrification, in which electrons produced by sediment microorganisms can be transferred to the upper layer of the water column lacking electron donors. However, the low efficiency of denitrifying bacteria in acquiring electrons and enriching at the cathode greatly hinders the application of SMFC for nitrogen removal. In this study, we report a novel method of constructing a high-performance biocathode by modifying electrodes with zero-valent iron to enhance the enrichment and electron transfer of electroactive bacteria.
View Article and Find Full Text PDFEnviron Pollut
December 2024
State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China.
The sulfate-reducing bacteria (SRB)-induced ferrihydrite transformation is an important cause for arsenic (As) contamination in the aquifer near mining area. Calcium carbonate (CaCO) is widespread and has the potential of regulating As fate directly or indirectly. However, the influence of CaCO on ferrihydrite transformation and the associated As mobilization/redistribution in SRB-containing environments remains unclear.
View Article and Find Full Text PDFLangmuir
December 2024
Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States.
Environmental DNA (eDNA), i.e., DNA found in the environment, can interact with various geochemical surfaces, yet little is known about these interactions.
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