Whilst there is increasing evidence for the presence of stabilized Fe(II) associated with organic matter in aquatic environments, the absence of a reliable method for determining Fe(II) speciation in solution has inhibited the study of this aspect of Fe biogeochemistry. A technique is described here for the determination of Fe(II) organic complexation in natural waters that is based on competitive ligand reverse titration and a model fit to experimental results, from which ligand concentration and a conditional stability constant can be obtained. Spectrophotometry was used to detect the Ferrozine (FZ) complex with reactive Fe(II), which in combination with a liquid waveguide capillary cell (LWCC) enabled high sensitivity and precision measurements of Fe(II) to be made. A series of samples was collected in the Itchen River in Southampton, UK to test the method at a wide range of salinities including river water. Levels of Fe(II) and total dissolved Fe were within previously reported values for this system. Fe(II) was found to occur organically complexed with values for K'(Fe(II)L) (conditional stability constant for Fe(II)-natural ligand complexes) of ≈8 at salinities between 0 and 21, whilst no measurable complexation was detected at a salinity of 31. This work demonstrates that spectrophotometry can be used in combination with ligand competition to investigate metal speciation in natural waters.
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http://dx.doi.org/10.1016/j.aca.2012.07.014 | DOI Listing |
Environ Sci Pollut Res Int
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Grupo de Investigación Materiales Con Impacto (Mat&Mpac), Facultad de Ciencias Básicas, Universidad de Medellín, Carrera 87 No. 30-65, 050026, Medellín, Colombia.
This study shows the efficiency of WH-C450, an adsorbent obtained from water hyacinth (WH) biomass, in the removal of sulfamethoxazole (SMX) from aqueous solutions. The process involves calcination of WH at 450 °C to produce an optimal adsorbent material capable of removing up to 73% of SMX and maximum SMX adsorption capacity of 132.23 mg/g.
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January 2025
Department of Agricultural Microbiology, Faculty of Agriculture, Ain Shams University, P.O. Box 68, Cairo, 11241, Egypt.
The increasing demand for natural alternatives to synthetic fungicides has prompted research into natural products like essential oils for postharvest disease management. This study investigated the antifungal, antioxidant, cytotoxic, and genotoxic potential of essential oil mixtures derived from oregano, rosemary, and mint against Penicillium digitatum, the predominant fungal pathogen causing green mold in orange fruits. P.
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January 2025
School of Natural Sciences, University of Tasmania, Private Bag 55, Hobart, TAS, 7001, Australia.
A gene within a single subclade of NCED genes is triggered in response to both, short- and long-term dehydration treatments, in three model dicot species. During dehydration, some plants can rapidly synthesise the stress hormone abscisic acid (ABA) in leaves within 20 min, triggering the closure of stomata and limiting further water loss. This response is associated with significant transcriptional upregulation of Nine-cis-Epoxycarotenoid Dioxygenase (NCED) genes, which encode the enzyme considered to be rate-limiting in ABA biosynthesis.
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January 2025
Department of Environmental Sciences & Engineering, Faculty of Agriculture & Natural Resources, Ardakan University, Ardakan, Iran.
Assessing the impact of climate change on water-related ecosystem services (ES) in Protected Areas (PAs) is essential for developing soil and water conservation strategies that promote sustainability and restore ES. However, the application of ES research in Protected Area (PA) management remains ambiguous and has notable shortcomings. This study primarily aimed to assess the SDR-InVEST (Sediment Delivery Ratio-Integrated Valuation of Ecosystem Services and Tradeoffs) model for estimating ES, including soil loss, sediment export, and sediment retention, under various climate change scenarios from 1997 to 2100 in the data-scarce region of the Bagh-e-Shadi Forest PA.
View Article and Find Full Text PDFInfect Dis Now
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Department of Global Health and Development, London School of Hygiene and Tropical Medicine, UK.
Antimicrobial resistance (AMR) poses a global health challenge, particularly in maritime environments where unique conditions foster its emergence and spread. Characterized by confined spaces, high population density, and extensive global mobility, ships create a setting ripe for the development and dissemination of resistant pathogens. This review aims to analyse the contributing factors, epidemiological challenges, mitigation strategies specific to AMR on ships and to propose future research directions, bridging a significant gap in the literature.
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