Sediments act as important sinks for metals and their radionuclides in aquatic environments and play a crucial role in their transfer and uptake to aquatic organisms. Traditional radioecological models use radionuclide concentrations in water to predict concentrations in aquatic organisms. In this study, we investigated the distribution of radioecologically important metals (Ba, Co, Ni, Sr, U) among sediment, porewater and hypolimnion over seasons. We also studied the uptake of these metals to benthic organisms and importance of sediment as an uptake source by conducting a 28-day in situ bioaccumulation experiment with oligochaete worms (Lumbriculus variegatus). The studied metals were chosen based on common occurrence of their radioactive isotopes in nuclear fuel cycle. Measurements of total elemental concentration were used as proxies to study the behavior of specific radionuclides. Sediment and water samples were collected from two small lakes connected to a former uranium mine in Eastern Finland, and from a nearby reference lake connected to a different drainage area. Environmental characteristics and concentrations measured from sediment, porewater and overlying water indicated only minor changes between seasons. Measured metals were highly associated with sediment particles, rather than porewater or hypolimnion. Both the distribution of metals and in situ experiment indicated the importance of sediment as the main source of bioaccumulation. Significant differences in Ba, Ni and U concentrations between treatments containing contaminated sediment and reference sediment were noted, regardless of water concentrations. Additionally, as U contaminated lakes lacked seasonal overturn during our monitoring period, metal distribution and environmental conditions remained unchanged in deeper parts of those lakes. Lastly, the results of this in situ bioaccumulation experiment are in line with the findings of our previous laboratory study using sediments from these same lakes.
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http://dx.doi.org/10.1016/j.scitotenv.2024.176696 | DOI Listing |
Environ Sci Technol
November 2024
Department of Exposure Science, Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, Leipzig 04318, Germany.
We applied passive equilibrium sampling using silicone-based chemometers to nine biota species, sediment, and water in a multimedia aquatic ecosystem. They allowed for direct comparison of the concentration of regulated and emerging hydrophobic organic compounds in the silicone across species as well as the comparison of biota with sediments and water. We derived chemometer-based trophic magnification factors (TMFs) of diverse compounds that agreed with the traditionally derived TMFs.
View Article and Find Full Text PDFAnal Chim Acta
November 2024
School of the Environment and Safety Engineering, And Collaborative Innovation Center of Technology and Material of Water Treatment, Jiangsu University, Zhenjiang, 212013, PR China; Fujian Provincial Key Laboratory of Modern Analytical Science and Separation Technology, Minnan Normal University, Zhangzhou, 363000, PR China; Fujian Key Laboratory of Agro-products Quality & Safety, Fuzhou, 350003, PR China. Electronic address:
J Environ Radioact
December 2024
China-ASEAN College of Marine Sciences (CAMS), Xiamen University Malaysia, Jalan Sunsuria, Bandar Sunsuria, 43900, Sepang, Selangor Darul Ehsan, Malaysia.
Sci Total Environ
December 2024
Department of Environmental and Biological Sciences, University of Eastern Finland, PO Box 111, FI-80101 Joensuu, Finland.
Environ Sci Technol
September 2024
College of Environmental Science and Engineering, Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Nankai University, 38 Tongyan Road, Tianjin 300350, China.
Conventional approaches for in situ remediation of mercury (Hg)-contaminated soils and sediments rely mostly on precipitation or adsorption. However, this can generate Hg-rich surfaces that facilitate microbial production of methylmercury (MeHg), a potent, bioaccumulative neurotoxin. Herein, we prove the concept that the risk of mercury methylation can be effectively minimized by adding sulfur-intercalated layered double hydroxide (S-LDH) to Hg-contaminated soils.
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