X-ray absorption near edge structure spectroscopy reveals phosphate minerals at surface and agronomic sampling depths in agricultural Ultisols saturated with legacy phosphorus.

Legacy phosphorus (P) soils have received excessive P inputs from historic manure and fertilizer applications and present unique management challenges for protecting water quality as soil P saturation leads to increased soluble P to waterways. We used P K-edge X-ray absorption near edge structure (XANES) spectroscopy to identify and quantify the dominant P minerals in four representative legacy P soils under conventional till and no-till management in Maryland, USA. Various measures of extractable soil P, including water-extractable P (20.

Fate and transformations of dissolved phosphorus forms in runoff: Effect of poultry litter and products extracted with variable water extraction ratios.

In many intensive animal production areas, the over-application of manure has resulted in a build-up of soil phosphorus (P) and the creation of legacy P soils that threaten water quality. We investigated dissolved P forms losses in runoff using simulated rainfall in packed soil boxes amended with three poultry litter and products, including raw (unprocessed) litter, granulated litter with the addition of urea, and heated raw litter. These were applied at 3 kg water-extractable P (WEP) ha as determined with three litter-to-water extraction ratios (1:10, 1:100, and 1:200).

Molecular characterization of dissolved organic nitrogen and phosphorus in agricultural runoff and surface waters.

Agricultural runoff is a significant contributor to nitrogen (N) and phosphorus (P) pollution in water bodies. Limited information is available about the molecular characteristics of the dissolved organic N (DON) and P (DOP) species in the agricultural runoff and surface waters. We employed Fourier Transform-Ion Cyclotron Resonance-Mass Spectrometry (FT-ICR-MS) to investigate the changes in the molecular characteristics of DON and DOP at three watershed positions (upstream water, runoff from agricultural fields, and downstream waters).

Nitrate-nitrogen transport in streamwater and groundwater in a loess covered region: Sources, drivers, and spatiotemporal variation.

Water quality is an increasing concern in the dry regions of the world as it affects and reduces the quantity of available water. Our objective was to investigate the sources, drivers, spatiotemporal patterns of nitrate‑nitrogen (NO-N) transport in the streamwater and groundwater in a dry and a wet season in seven large rivers located in the Loess Plateau of China (640,000 km, 100 million population), which is a region with marked influence of human activities on streamflow and groundwater. We collected 510 streamwater and groundwater samples and found that NO-N was significantly lower in the dry season (< 5.

Residential catchments to coastal waters: Forms, fluxes, and mechanisms of phosphorus transport.

Controlling phosphorus (P) loss from land to water bodies is of immense scientific and societal interest and scrutiny. We investigated P forms in a longitudinal gradient in three typical urban junctions: stormwater from a residential catchment, pond discharges from a stormwater retention pond, and 13 coastal waters (rivers and estuary). Concentrations of total P (TP) were 122.

Enriched dissolved organic carbon export from a residential stormwater pond.

In urban watersheds, stormwater retention ponds are intermediate junctions that capture, store, and discharge stormwater, and provide an organic-rich environment that transforms and retains nutrients and other constituents. This study investigated the concentrations and loads of dissolved and particulate organic carbon (DOC and POC) in discharges from a stormwater retention pond that receives runoff from a residential catchment. We installed an autosampler, a flowmeter, and a rain gauge at the outlet (weir) of the stormwater retention pond and collected samples from 13 storm events during the 2016 wet season (May-September).

Wet season nitrogen export from a residential stormwater pond.

Stormwater runoff is recognized as a cause of water quality degradation because it may carry nitrogen (N) and other pollutants to aquatic ecosystems. Stormwater ponds are a stormwater control measure often used to manage stormwater runoff by holding a permanent pool of water, which reduces the peak flow, magnitude of runoff volume, and concentrations of nutrients and pollutants. We instrumented the outlet of a stormwater pond in an urban residential neighbourhood in Florida, United States to (1) investigate the concentration and composition of N forms during the summer rainy season (May to September 2016), and (2) determine the bioavailability of organic N in the stormwater pond with a bioassay experiment.

Composition of nitrogen in urban residential stormwater runoff: Concentrations, loads, and source characterization of nitrate and organic nitrogen.

Stormwater runoff is a leading cause of nitrogen (N) transport to water bodies and hence one means of water quality deterioration. Stormwater runoff was monitored in an urban residential catchment (drainage area: 3.89 hectares) in Florida, United States to investigate the concentrations, forms, and sources of N.

Organic nitrogen in residential stormwater runoff: Implications for stormwater management in urban watersheds.

Stormwater runoff containing organic nitrogen (N) is a source of potentially bioavailable N in water bodies. Characterization and concentrations of dissolved organic N (DON) and particulate organic N (PON) in urban stormwater runoff are rarely reported and considered in stormwater management. Our objectives were to (1) characterize the organic (DON, PON) and inorganic (NO and NH) N pools in residential stormwater runoff and (2) determine the rainfall driven landscape sources of runoff PON using an isotopic mixing model with C and N during a wet season (June-September).

Xen45 Gel Stent implant: patient reported outcomes.

Our aim was to report quality of life (QOL) outcomes following Xen45 Gel Stent implantation surgery in patients suffering with primary open angle glaucoma (POAG). A retrospective analysis was performed on all patients who had Xen45 implantation surgery during a 2-year period (Jun, 2016-Apr, 2018). Of 52 consecutive patients were included with a total of 58 eyes being operated on.

Blood Transcriptomics Analysis of Fish Exposed to Perfluoro Alkyls Substances: Assessment of a Non-Lethal Sampling Technique for Advancing Aquatic Toxicology Research.

In contrast to mammals, the blood from other vertebrates such as fish contains nucleated red cells. Using a fathead minnow ( Pimephales promelas) oligonucleotide microarray, we compared altered transcripts in the liver and whole blood after exposure to environmentally relevant concentrations of perfluorooctanesulfonic acid (PFOS) and a mixture of seven types of perfluoro alkyl substances (PFAS), including perfluorooctanoic acid (PFOA). We used quantitative polymerase chain reactions and cell-based assays to confirm the main effects and found that blood responded with a greater number of altered genes than the liver.

Stormwater runoff driven phosphorus transport in an urban residential catchment: Implications for protecting water quality in urban watersheds.

Increased stormwater runoff in urban watersheds is a leading cause of nonpoint phosphorus (P) pollution. We investigated the concentrations, forms, and temporal trends of P in stormwater runoff from a residential catchment (31 low-density residential homes; 0.11 km drainage area) in Florida.

Composition, sources, and bioavailability of nitrogen in a longitudinal gradient from freshwater to estuarine waters.

Nitrogen (N) transport from land to water is a dominant contributor of N in estuarine waters leading to eutrophication, harmful algal blooms, and hypoxia. Our objectives were to (1) investigate the composition of inorganic and organic N forms, (2) distinguish the sources and biogeochemical mechanisms of nitrate-N (NO-N) transport using stable isotopes of NO and Bayesian mixing model, and (3) determine the dissolved organic N (DON) bioavailability using bioassays in a longitudinal gradient from freshwater to estuarine ecosystem located in the Tampa Bay, Florida, United States. We found that DON was the most dominant N form (mean: 64%, range: 46-83%) followed by particulate organic N (PON, mean: 22%, range: 14-37%), whereas inorganic N forms (NO-N: 7%, NH-N: 7%) were 14% of total N in freshwater and estuarine waters.

Characterization of dissolved organic nitrogen in leachate from a newly established and fertilized turfgrass.

Understanding the mechanisms of nitrogen (N) retention and loss from fertilized urban turfgrass is critical to develop practices that mitigate N transport and protect water quality in urban ecosystems. We investigated the fate of N in lysimeters sodded with St. Augustine turfgrass and amended with labeled N from either ammonium sulfate or urea.

Micropollutants in groundwater from septic systems: Transformations, transport mechanisms, and human health risk assessment.

Septic systems may contribute micropollutants to shallow groundwater and surface water. We constructed two in situ conventional drainfields (drip dispersal and gravel trench) and an advanced drainfield of septic systems to investigate the fate and transport of micropollutants to shallow groundwater. Unsaturated soil-water and groundwater samples were collected, over 32 sampling events (January 2013 to June 2014), from the drainfields (0.

Managing urban runoff in residential neighborhoods: Nitrogen and phosphorus in lawn irrigation driven runoff.

Sources and mechanisms of nutrient transport in lawn irrigation driven surface runoff are largely unknown. We investigated the transport of nitrogen (N) and phosphorus (P) in lawn irrigation driven surface runoff from a residential neighborhood (28 ha) of 56% impervious and 44% pervious areas. Pervious areas encompassing turfgrass (lawns) in the neighborhood were irrigated with the reclaimed water in common areas during the evening to late night and with the municipal water in homeowner's lawns during the morning.

Sources and mechanisms of nitrate and orthophosphate transport in urban stormwater runoff from residential catchments.

Nutrients export from residential catchments contributes to water quality impairment in urban water bodies. We investigated the concentrations, transport mechanisms, and sources of nitrate-nitrogen (NO-N) and orthophosphate-phosphorus (PO-P) in urban stormwater runoff generated in residential catchments in Tampa Bay, Florida, United States. Street runoff samples, collected over 21 storm events, were supplemented with rainfall and roof runoff samples from six representative residential catchments.

Septic Systems Contribution to Phosphorus in Shallow Groundwater: Field-Scale Studies Using Conventional Drainfield Designs.

Septic systems can be a potential source of phosphorus (P) in groundwater and contribute to eutrophication in aquatic systems. Our objective was to investigate P transport from two conventional septic systems (drip dispersal and gravel trench) to shallow groundwater. Two new in-situ drainfields (6.

High Removal of Effluent-borne Nitrogen with Multiple External Electron Donors in the Engineered Drainfield of an Advanced Septic System.

Septic systems can be a major source of nitrogen (N) in shallow groundwater. We designed an in situ engineered drainfield with aerobic-anaerobic (sand-woodchips) and anaerobic (elemental sulfur-oyster shell) media to remove N in the vadose zone and reduce N transport to groundwater. Effluent was dispersed on top of the engineered drainfield (3.

Latin American protected areas: Protected from chemical pollution?

Protected areas (PAs) are critically important means to preserve species and maintain natural ecosystems. However, the potential impacts of chemical pollution on PAs are seldom mentioned in the scientific literature. Research on the extent of the occurrence of chemical pollution inside PAs and in-depth assessments of how chemical contaminants may adversely affect the maintenance of species abundance, species survival, and ecosystem functions are scarce to nonexistent.

Mass Balance of Water and Nitrogen in the Mounded Drainfield of a Drip-Dispersal Septic System.

Quantitative assessment of nitrogen (N) loading from septic systems is needed to protect groundwater contamination. We determined the mass balance of water and N in the mounded drainfield of a drip-dispersal septic system. Three lysimeters (152.

Phosphorus Leaching in Soils Amended with Animal Manures Generated from Modified Diets.

New dietary modifications for dairy (reducing P content in feed) and poultry (addition of feed additives such as phytase) aim to reduce P excretion in manures. Our objective was to investigate if dietary changes were effective at reducing P leaching loss on land application of manures. We used 54 undisturbed lysimeters (30 cm diameter, 50 cm deep) collected from three typical mid-Atlantic soils.

Septic systems as hot-spots of pollutants in the environment: Fate and mass balance of micropollutants in septic drainfields.

Septic systems, a common type of onsite wastewater treatment systems, can be an important source of micropollutants in the environment. We investigated the fate and mass balance of 17 micropollutants, including wastewater markers, hormones, pharmaceuticals and personal care products (PPCPs) in the drainfield of a septic system. Drainfields were replicated in lysimeters (1.