Surface sediments are both sinks and sources of chlorinated and brominated polycyclic aromatic hydrocarbons (Cl/Br-PAHs) in the environment. It is important to study the source of Cl/Br-PAHs in the surface sediment for controlling the ecological risk of Cl/Br-PAHs. Clues from the previous research suggested that atmospheric deposition may be one of the main sources of Cl/Br-PAHs in sediment. However, due to the lack of matched sediment and atmospheric Cl/Br-PAHs data, the contribution of atmospheric deposition to Cl/Br-PAHs in sediment has not been confirmed. This study investigated the characteristics of 37 Cl/Br-PAHs and validated the contribution of atmospheric sedimentation to Cl/Br-PAHs in sediment by a case study in the surface sediments of the Chaobai River, China. To the best of our knowledge, four Cl-PAHs and eleven Br-PAHs were found in the sediments for the first time. The total concentrations of 18 Cl-PAH species were 76-2301 pg/g, while those of Br-PAHs were 6-238 pg/g. The toxic equivalent quantities (TEQ) of the Cl-PAHs in surface sediments in the water conservation area and in the urban comparison area were 0.73 pg TEQ/g and 2.21 pg TEQ/g, respectively. The TEQ of the Br-PAHs in surface sediments in the water conservation area and in the urban comparison area were 2.85 × 10 pg TEQ/g and 6.6 × 10 pg TEQ/g, respectively. Based on the characteristics comparison and correlation analysis of Cl/Br-PAHs in both sediment and ambient air, it was initially confirmed the contribution of atmospheric deposition to Cl-PAHs in sediments. However, there was no conclusion of Br-PAHs in sediment similar to Cl-PAHs in sediment. It was inferred that the sources of Br-PAHs in sediment were different from Cl-PAHs in sediment.
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http://dx.doi.org/10.1016/j.scitotenv.2021.152889 | DOI Listing |
Nat Geosci
January 2025
School of Earth and Environment, University of Leeds, Leeds, UK.
Controls on organic carbon preservation in marine sediments remain controversial but crucial for understanding past and future climate dynamics. Here we develop a conceptual-mathematical model to determine the key processes for the preservation of organic carbon. The model considers the major processes involved in the breakdown of organic carbon, including dissolved organic carbon hydrolysis, mixing, remineralization, mineral sorption and molecular transformation.
View Article and Find Full Text PDFEnviron Sci Process Impacts
January 2025
Environmental Modelling Group, Department of Science and High Technology (DiSAT), University of Insubria, Como, 22100, Italy.
Microcontaminants (MCs) and microplastics (MPs) originating from the textile sector are today receiving a great deal of attention due to potential environmental concerns. Environmental pressures and impacts related to the textile system include not only the use of resources (, water) but also the release of a wide variety of pollutants. This review's main objective is to highlight the presence of textile MCs and MPs in water, in their full path from textile factories (from raw materials to the final product) to wastewater treatment plants (WWTPs), and finally to the receiving surface waters.
View Article and Find Full Text PDFMar Pollut Bull
January 2025
Department of Chemical Oceanography, Cochin University of Science and Technology, Cochin 682016, India. Electronic address:
This study examines the presence of potentially toxic elements (PTEs) in the surface sediments and water of the Ashtamudi wetland, a Ramsar site on India's southwest coast. The average concentration of PTEs in water(μg/L) and in sediments (mg/kg) follows the order Fe(147.89) > Zn(107.
View Article and Find Full Text PDFSci Total Environ
January 2025
College of Marine Sciences, South China Agricultural University, Guangzhou 510642, China; Zhongshan Innovation Center of South China Agricultural University, Zhongshan 528400, China. Electronic address:
Mangrove sediments in southern China are a large reservoir for microplastics (MPs). In particular, polyethylene microplastics (PE-MPs) are environmentally toxic and have accumulated in large quantities in these sediments, posing a potential threat to the overall mangrove and the organisms that inhabit it. We screened sediments from 5 mangrove sites and identified a potential source of PE-MP degrading bacteria.
View Article and Find Full Text PDFSci Adv
January 2025
Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA.
Symmetrical wave ripples identified with NASA's Curiosity rover in ancient lake deposits at Gale crater provide a key paleoclimate constraint for early Mars: At the time of ripple formation, climate conditions must have supported ice-free liquid water on the surface of Mars. These features are the most definitive examples of wave ripples on another planet. The ripples occur in two stratigraphic intervals within the orbitally defined Layered Sulfate Unit: a thin but laterally extensive unit at the base of the Amapari member of the Mirador formation, and a sandstone lens within the Contigo member of the Mirador formation.
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