Stream sediments from mine area are a converging source of water and soil pollution. The risk and development trends of metal(loid)s pollution in sediments from an abandoned arsenic-containing mine were studied using modelling techniques. The results showed that the combined techniques of geographic information system (GIS), random forest (RF), and numerical simulation (NS) could identify risk sources and diffusion trends of metal(loid)s in mine sediments. The median values of As, Cd, Hg, and Sb in sediments were 5.01, 3.02, 5.67, and 3.20 times of the background values of stream sediments in China, respectively. As (14.09%) and Hg (18.64%) pollution in mine stream sediments were severe while As is the main potential risk source with a strong spatial correlation. High-risk blocks were concentrated in the landfill area, with the surrounding pollution shows a decreasing trend of "step-type" pollution. The risk correlation between Hg and As (55.37%) in the landfill area is high. As a case of arsenic, the diffusion capacity of As within 500m is strong and stabilizes at 1 km when driven by the flows of 0.05, 0.5, and 5 m/s, respectively. With the worst-case scenario flow (86 m/s), it would take only 147 days for the waters within 3 km to become highly polluted. The high pollution levels in a stream under forecast of different distance intervals (500, 1500, 2000 m) within 6.5 km is arrived at approximate 344, 357, and 384 days, respectively. The study suggested the combined technique of GIS, RF, and NS can serve the risk source identification of contaminated sites and risk forecast of toxic element diffusion in emergency situations.
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http://dx.doi.org/10.1016/j.envpol.2023.121713 | DOI Listing |
Sci Total Environ
January 2025
Department of Forest Science, College of Agriculture, University of São Paulo (ESALQ), Av. Padua Dias, 11, Caixa Postal 9, 13418-900 Piracicaba, SP, Brazil.
Forest restoration has been a common practice to safeguard water quality and stream health but it is unclear to which extent and pace forest restoration recovers stream ecosystem structure and functions. Also, stream health might be affected by the forest restoration type and the quality of the interventions. Here, we sought to evaluate the recovery of stream habitat and water quality through forest restoration in catchments dominated by pasturelands, and explored the relationship between landscape structure and stream ecosystem recovery.
View Article and Find Full Text PDFJ Environ Manage
January 2025
Xi'an Key Laboratory of Environmental Simulation and Ecological Health in the Yellow River Basin, College of Urban and Environmental Sciences, Northwest University, Xi'an, 710127, China; Yellow River Institute of Shaanxi Province, Northwest University, Xi'an, 710127, China.
Different speciation of phosphorus in the hyporheic zone exhibit various release potentials, so as to control the phosphorus content in the overlying water. The process of phosphorus release under the multi-factor coupling of rivers is crucial for understanding the element cycle in complex environments. In this paper, the Weihe River in China was used as a case study to analyze the phosphorus speciation and distribution of overlying water and sediments in the hyporheic zone, and the phosphorus release process of sediments under the coupling of multiple factors.
View Article and Find Full Text PDFEcol Appl
January 2025
U.S. Geological Survey, Lower Mississippi-Gulf Water Science Center, Jackson, Mississippi, USA.
Subsidy-stress gradients offer a useful framework for understanding ecological responses to perturbation and may help inform ecological metrics in highly modified systems. Historic, region-wide shifts from bottomland hardwood forest to row crop agriculture can cause positively skewed impact gradients in alluvial plain ecoregions, resulting in tolerant organisms that typically exhibit a subsidy response (increased abundance in response to environmental stressors) shifting to a stress response (declining abundance at higher concentrations). As a result, observed biological tolerance in modified ecosystems may differ from less modified regions, creating significant challenges for detecting biological responses to restoration efforts.
View Article and Find Full Text PDFEnviron Sci Technol
January 2025
Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada.
The ubiquitous distribution of microplastics (MPs) in aquatic environments is linked to their transport in rivers and streams. However, the specific mechanism of bedload microplastic (MP) transport, notably their stochastic behaviors, remains an underexplored area. To investigate this, particle tracking velocimetry was employed to examine the continuous near-bed movements of four types of MPs under nine setups with different experimental conditions in a laboratory flume, with an emphasis on their streamwise transport.
View Article and Find Full Text PDFHeliyon
July 2024
Chemistry Department, University of Idaho, Moscow, USA.
This study determined the concentrations and seasonal variations of phthalate esters (PAEs) in water and sediment samples of the receiving stream within the vicinity of the Obafemi Awolowo University, Ile-Ife dumpsite. The objective of this study was to evaluate the pollution status of the study area by determining the levels of PAEs in water and sediment samples. This assessment aimed to understand the presence and extent of phthalate ester pollution in the study area.
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