Most treatment practices for urban runoff capture pollutants such as phosphorus by either settling or filtration while dissolved phosphorus, typically as phosphates, is untreated. Dissolved phosphorus, however, represents an average 45% of total phosphorus in stormwater runoff and can be more than 95%. In this study, a new stormwater treatment technology to capture phosphate, called the Minnesota Filter, is introduced. The filter comprises iron filings mixed with sand and is tested for phosphate removal from synthetic stormwater. Results indicate that sand mixed with 5% iron filings captures an average of 88% phosphate for at least 200 m of treated depth, which is significantly greater than a sand filter without iron filings. Neither incorporation of iron filings into a sand filter nor capture of phosphates onto iron filings in column experiments had a significant effect on the hydraulic conductivity of the filter at mixtures of 5% or less iron by weight. Field applications with up to 10.7% iron were operated over 1 year without detrimental effects upon hydraulic conductivity. A model is applied and fit to column studies to predict the field performance of iron-enhanced sand filters. The model predictions are verified through the predicted performance of the filters in removing phosphates in field applications. Practical applications of the technology, both existing and proposed, are presented so stormwater managers can begin implementation.
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http://dx.doi.org/10.1016/j.watres.2012.03.009 | DOI Listing |
J Environ Manage
January 2025
Civil, Construction and Environmental Engineering, Marquette University, 1637 W. Wisconsin Ave, Milwaukee, WI, USA. Electronic address:
Green stormwater infrastructure is growing in adoption across the world due to its ability to capture and treat stormwater runoff at the source; however, while green stormwater infrastructure is effective at reducing the concentration of many priority pollutants, bioretention often increases the concentration of dissolved phosphorus in the stormwater it treats. This is a significant shortcoming, as dissolved phosphorus can promote algae growth in receiving water bodies resulting in negative impacts to human and aquatic health. This study seeks to address this shortcoming through an end-of-pipe filter at the end of bioretention effluent pipes designed to reduce the concentration of dissolved phosphorus.
View Article and Find Full Text PDFBone fracture ruptures blood vessels and disrupts the bone marrow, the site of new red blood cell production (erythropoiesis). Current dogma holds that bone fracture causes severe hypoxia at the fracture site, due to vascular rupture, and that this hypoxia must be overcome for regeneration. Here, we show that the early fracture site is not hypoxic, but instead exhibits high oxygen tension (> 55 mmHg, or 8%), similar to the red blood cell reservoir, the spleen.
View Article and Find Full Text PDFJ Phys Chem Lett
January 2025
Department of Chemistry, Malaviya National Institute of Technology, Jaipur, Jaipur 302017, India.
Herein, a simple ambient conditioned sunlight promoted photochemical reduction reaction is demonstrated for the of nitrate (NO) conversion to ammonia (NH) with the maximum conversion yield of ∼16 mM using iron filings (f-Fe) in the presence of HO. Based on a radical scavenging study of reactive species and the characterization of catalyst f-Fe before and after the reaction, a plausible mechanism has been proposed for the ambient conditioned synthesis of NH. The results associated with the NH synthesis have been verified using the N isotopic labeled nitrate (NO), which supports the simpler viability of the reported procedure.
View Article and Find Full Text PDFNat Rev Dis Primers
January 2025
European Reference Network for Rare Multisystemic Vascular Disease (VASCERN), HHT Rare Disease Working Group, Paris, France.
Hereditary haemorrhagic telangiectasia (HHT) is a vascular dysplasia inherited as an autosomal dominant trait and caused by loss-of-function pathogenic variants in genes encoding proteins of the BMP signalling pathway. Up to 90% of disease-causal variants are observed in ENG and ACVRL1, with SMAD4 and GDF2 less frequently responsible for HHT. In adults, the most frequent HHT manifestations relate to iron deficiency and anaemia owing to recurrent epistaxis (nosebleeds) or bleeding from gastrointestinal telangiectases.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Department of Chemical Engineering, Stanford University, Stanford, CA 94305.
High degree of fluorination for ether electrolytes has resulted in improved cycling stability of lithium metal batteries due to stable solid electrolyte interphase (SEI) formation and good oxidative stability. However, the sluggish ion transport and environmental concerns of high fluorination degree drive the need to develop less fluorinated structures. Here, we depart from the traditional ether backbone and introduce bis(2-fluoroethoxy)methane (F2DEM), featuring monofluorination of the acetal backbone.
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