REEs in wetland sediments from the Oaxaca coast in southern Mexico were used to infer the sources and depositional processes by involving both the geochemical characteristics and geostatistical approaches. Statistically strong positive correlation between REEs confirmed similar origin in all the cores. Light REEs (LREEs) represented >84 % of ΣREE mean concentrations varies between 47.95 (C1) and 87.84 mg/kg (C3). NASC normalized La/Yb, La/Sm, and Gd/Yb ratios indicated more Middle REEs in sediments of C1 and C3 cores and more LREEs in C2 and C4 cores indicating the different mineralogical associations. The absence of Ce anomaly and significant negative Eu anomalies is due to the presence of Fe/Mn oxy-hydroxide, humid subtropical conditions and a strong leaching process. Comparison with REE and possible sources revealed contributions from the Sierra Madre del Sur Mountains with major influences of igneous rocks such as andesite, basaltic andesite, dacite, rhyolitic tuff and rhyolitic vitrophyre.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.marpolbul.2024.117506 | DOI Listing |
Water Res
January 2025
College of Environmental Science and Engineering and Key Laboratory of Environmental Biology and Pollution Control (Ministry of Education), Hunan University, Changsha 410082, PR China. Electronic address:
Anaerobic digestion (AD) is a biological process in which anaerobic microorganisms convert organic matter into methane-rich gas, contributing to the cycling of carbon and other nutrients. Quorum sensing (QS), a microbial communication mechanism, plays a critical role in regulating population-level behaviors within AD systems. This review systematically examines the roles and applications of QS in AD, emphasizing its importance in enhancing process efficiency.
View Article and Find Full Text PDFSci Total Environ
January 2025
US Geological Survey, New England Water Science Center, Northborough, MA, USA.
Groundwater-dependent ecosystems in areas with industrial land use are at risk of exposure to a PFAS chemicals. We investigated one such system with several known PFAS source areas, where high and low permeability sediments (glacial) coupled with groundwater-lake and groundwater/surface-water interactions created complex 'source to seep' dynamics. Using heat-tracing and chemical methods, numerous preferential groundwater discharge zones were identified and sampled across the upper Quashnet River stream-wetland system in Mashpee, MA, USA, downgradient of Joint Base Cape Cod (JBCC).
View Article and Find Full Text PDFJ Environ Sci (China)
July 2025
School of Environmental Science and Engineering, Yancheng Institute of Technology, Yancheng 224051, China; Jiangsu Province Ecology and Environment Protection Key Laboratory of Ecology and Pollution Control of Coastal Wetlands, Yancheng 224051, China.
Arsenic (As) pollution in coastal wetlands has been receiving growing attention. However, the exact mechanism of As mobility driven by tidal action is still not completely understood. The results reveal that lower total As concentrations in solution were observed in the flood-ebb treatment (FE), with the highest concentration being 7.
View Article and Find Full Text PDFMar Drugs
December 2024
Key Laboratory of Tropical Medicinal Resource Chemistry of Ministry of Education, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158, China.
Mangrove ecosystems have attracted widespread attention because of their high salinity, muddy or sandy soil, and low pH, as well as being partly anoxic and periodically soaked by tides. Mangrove plants, soil, or sediment-derived fungi, especially the species, possess unique metabolic pathways to produce secondary metabolites with novel structures and potent biological activities. This paper reviews the structural diversity and biological activity of secondary metabolites isolated from mangrove ecosystem-derived species over the past 5 years (January 2020-October 2024), and 417 natural products (including 170 new compounds, among which 32 new compounds were separated under the guidance of molecular networking and the OSMAC approach) are described.
View Article and Find Full Text PDFExamining the impacts of natural and anthropogenic influences on aquatic macrophytes in shallow lakes is crucial for their effective restoration and management. However, there is a lack of direct evidence regarding past species composition or detailed and continuous evidence of recent changes in aquatic macrophyte communities. This study utilized plant macrofossil remains deposited in the sediment, combined with macrophyte surveys from 1983 to 2010, to reconstruct the historical changes in the macrophyte community over approximately 160 years in Lake Weishan, a sub-lake of Lake Nansi located in the lower Yellow River (Huanghe River) Basin, northern China.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!