The objective of the present study was to assess the influence of extreme pH and redox potential (Eh) conditions on phosphorus (P) retention within the surface sludge deposit layer of a vertical flow constructed wetland (VFCW) where phosphorus was captured by FeCl3 injection. Series of 27 successive batch leaching tests were conducted under acidic, alkaline or reductive conditions using a representative sludge sample taken from an 8-year old VFCW plant. Experiments were followed by monitoring the pH and Eh variations and analysing the releases of P and other selected elements into the solutions. The sludge material was also analyzed before and after leaching, using solution (31)P NMR spectroscopy and sequential chemical extractions, in order to evaluate dissolutions of both organic and inorganic P-bearing species and their respective contributions to P release. The correlations between the monitored variables were analyzed and visualized through principal components analyses (PCA). Results showed a very good stability of P retention in the sludge deposit and a relatively good acid-buffering capacity of the sludge, revealing that the risk of accidental P release into the environment would be extremely low during the real plant operation.
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http://dx.doi.org/10.1016/j.jenvman.2016.08.064 | DOI Listing |
Huan Jing Ke Xue
January 2025
Wuhan Center, China Geological Survey (Central South China Innovation Center for Geosciences), Wuhan 430205, China.
Nitrate pollution in water bodies is a worldwide environmental problem, and identifying the sources of nitrate is of great significance to guarantee the sustainable use of water resources. A variety of water chemistry indicators and nitrate nitrogen and oxygen isotopes (N-NO and O-NO) were used to analyze the water chemistry characteristics of water bodies in Shiyan to identify the sources of nitrate in the water bodies and to calculate the contribution rate of nitrate from different pollution sources of the water bodies using the SIMMR model. The results showed that the hydrochemical types of surface water and groundwater in the study area were dominated by the HCO-Ca·Mg type, and the formation of nitrate in the water body was mainly affected by nitrification, with non-obvious denitrification.
View Article and Find Full Text PDFMicroorganisms
October 2024
Department of Biology, University of Ottawa, Marie-Curie Private, Ottawa, ON K1N 6N5, Canada.
Well-annotated gene and genomic sequences serve as a foundation for making inferences in molecular biology and evolution and can directly impact public health. The first SARS-CoV-2 genome was submitted to the GenBank database hosted by the U.S.
View Article and Find Full Text PDFJ Xenobiot
November 2024
Departamento de Micro y Nanotecnologías, Instituto de Ciencias Aplicadas y Tecnología, Universidad Nacional Autónoma de México (ICAT-UNAM), Circuito Exterior S/N, Ciudad de México 04510, Mexico.
Contamination of marine ecosystems by pharmaceutically active compounds (PhACs) deserves more research since their environmental fate differs from that observed in freshwater systems. However, knowledge remains scarce, especially in semi-arid coastal regions of the Global South. This study investigates the occurrence and distribution of caffeine, carbamazepine, ciprofloxacin, and sulfamethoxazole in sediments from the La Paz lagoon, a coastal system in a semi-arid region of Mexico with inverse estuarine conditions.
View Article and Find Full Text PDFWater Res
January 2025
Graduate School of Engineering, Kyoto University, Kyoto 615-8530, Japan.
Virus Genes
November 2024
Department of Epidemiology and Biostatistics, School of Public Health, Anhui Medical University, Hefei, China.
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