Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory-Evaluation of alkaline persulfate digestion as an alternative to Kjeldahl digestion for determination of total and dissolved nitrogen and phosphorus in water

Patton, Charles J.; Kryskalla, Jennifer R.

doi:10.3133/wri034174

Cited by 81 publications

(18 citation statements)

References 17 publications

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“…Whole water samples for total nitrogen and total phosphorus analyzed by the USGS were preserved with 1.0 mL of 1:7 sulfuric acid and chilled on ice. Samples were analyzed at the USGS NWQL for concentrations of dissolved nitrite, dissolved nitrate plus nitrite, dissolved ammonia, dissolved orthophosphate, total nitrogen, and total phosphorus per standard USGS methods (Fishman 1993;Patton and Kryskalla 2003;Patton and Kryskalla 2011).…”

Section: Measurement Of Microcystins and Nutrient Concentrations Phymentioning

confidence: 99%

Predicting microcystin concentration action-level exceedances resulting from cyanobacterial blooms in selected lake sites in Ohio

Francy

Brady

Stelzer

et al. 2020

Environ Monit Assess

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Cyanobacterial harmful algal blooms and the toxins they produce are a global water-quality problem. Monitoring and prediction tools are needed to quickly predict cyanotoxin action-level exceedances in recreational and drinking waters used by the public. To address this need, data were collected at eight locations in Ohio, USA, to identify factors significantly related to observed concentrations of microcystins (a freshwater cyanotoxin) that could be used in two types of sitespecific regression models. Real-time models include easily or continuously-measured factors that do not require that a sample be collected; comprehensive models use a combination of discrete sample-based measurements and real-time factors. The study sites included two recreational sites and six water treatment plant sites. Real-time models commonly included variables such as phycocyanin, pH, specific conductance, and streamflow or gage height. Many real-time factors were averages over time periods antecedent to the time the microcystin sample was collected, including waterquality data compiled from continuous monitors. Comprehensive models were useful at some sites with lagged variables for cyanobacterial toxin genes, dissolved nutrients, and (or) nitrogen to phosphorus ratios. Because models can be used for management decisions, important measures of model performance were sensitivity, specificity, and accuracy of estimates above or below the microcystin concentration threshold standard or action level. Sensitivity is how well the predictive tool correctly predicts exceedance of a threshold, an important measure for water-resource managers. Sensitivities > 90% at four Lake Erie water treatment plants indicated that models with continuous monitor data were especially promising. The planned next steps are to collect more data to build larger site-specific datasets and validate models before they can be used for management decisions.

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Section: Measurement Of Microcystins and Nutrient Concentrations Phymentioning

confidence: 99%

Predicting microcystin concentration action-level exceedances resulting from cyanobacterial blooms in selected lake sites in Ohio

Francy

Brady

Stelzer

et al. 2020

Environ Monit Assess

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“…Trace-element analytical methods are published in Fishman and Friedman (1989), Garbarino (1999), and Garbarino and others (2006). Nutrients analytical methods are published in Fishman (1993) and Patton and Kryskalla (2003). Organic compounds analysis methods are published in Zaugg and others (1995), Lindley and others (1996), Sandstrom and others (2001), and Madsen and others (2003).…”

Section: Methodsmentioning

confidence: 99%

Hydrogeologic framework, geochemistry, groundwater-flow system, and aquifer hydraulic properties used in the development of a conceptual model of the Ogallala, Edwards-Trinity (High Plains), and Dockum aquifers in and near Gaines, Terry, and Yoakum Counties, Texas

Teeple¹,

Ging²,

Thomas³

et al. 2021

Scientific Investigations Report

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“…Methods for major ions are published in Fishman and Friedman (1989) and Fishman (1993). Nutrients methods are published in Patton and Truitt (2000) and Patton and Kryskalla (2003). Trace-element methods are published in Fishman and Friedman (1989), Struzeski and others (1996), Garbarino (1999), and Garbarino and others (2006).…”

Section: Methodsmentioning

confidence: 99%

Geochemical assessment of the Hueco Bolson, New Mexico and Texas, 2016–17

Ging¹,

Humberson²,

Ikard³

2020

Scientific Investigations Report

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Understanding groundwater quality in transboundary aquifers like the Hueco Bolson is important for the 2.7 million people along the United States and Mexico border living in and near the combined metropolitan areas of Ciudad Juárez, Mexico, and El Paso, Texas, who rely on groundwater for water supply. To better understand water-quality conditions in the Mexico-New Mexico-Texas transboundary area, 23 water-supply wells were sampled in the Hueco Bolson within the United States near El Paso, Tex., during August-September 2016 and May-June 2017. Groundwater samples were analyzed for physical properties, major ions, dissolved solids, nutrients, trace elements, organic compounds, and selected isotopes such as strontium, hydrogen, oxygen, tritium, and carbon-14.Most of the water samples from the Hueco Bolson watersupply wells were classified as a sodium-chloride type water. Only four wells sampled in the study area had dissolved-solids concentrations greater than 1,000 milligrams per liter (mg/L), with three of those wells closest to the Rio Grande/Río Bravo del Norte (hereinafter referred to as the Rio Grande).Nitrate concentrations in the groundwater samples collected in the study area ranged from below the long-term method detection level of 0.04 to 6.2 mg/L. Arsenic was the only trace element detected in the wells sampled that had concentrations exceeding the designated drinking-water standard of 10 micrograms per liter (μg/L). Four of the 23 wells had arsenic concentrations greater than 10 μg/L, and these wells were all located near the Rio Grande. Three of the wells with the highest uranium concentrations (greater than 10 μg/L) were also located near the Rio Grande, and two of those wells were the same wells that had arsenic concentrations greater than 10 μg/L. Groundwater samples were analyzed for 83 organic compounds, but only 6 were detected-simazine, prometryn, prometon, atrazine, deethylatrazine, and dichloroaniline. All concentrations for the organic compounds detected were less than 0.03 μg/L, and the detections were only in five groundwater wells, three of which were located near the Rio Grande.Strontium, hydrogen, and oxygen isotopic values indicate that recharge water to the central and northern sections of the study area originates from near the Franklin Mountains, whereas groundwater in the southern section of the study area is likely from the Rio Grande valley. Tritium and carbon-14 values indicate that most of the wells that were sampled contained water that is considered premodern, which means that it is more than several hundred years old. Three wells with modern groundwater (approximately less than 70 years old) are located near the Rio Grande and are the same wells that had elevated arsenic or uranium concentrations and organic compound detections. Most of the results of the geochemical analyses indicate that groundwater near the Rio Grande has higher dissolved-solids concentrations, higher concentrations of several trace elements, and slightly more organic compound detections than the groundwate...

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Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory-Evaluation of alkaline persulfate digestion as an alternative to Kjeldahl digestion for determination of total and dissolved nitrogen and phosphorus in water

Cited by 81 publications

References 17 publications

Predicting microcystin concentration action-level exceedances resulting from cyanobacterial blooms in selected lake sites in Ohio

Predicting microcystin concentration action-level exceedances resulting from cyanobacterial blooms in selected lake sites in Ohio

Hydrogeologic framework, geochemistry, groundwater-flow system, and aquifer hydraulic properties used in the development of a conceptual model of the Ogallala, Edwards-Trinity (High Plains), and Dockum aquifers in and near Gaines, Terry, and Yoakum Counties, Texas

Geochemical assessment of the Hueco Bolson, New Mexico and Texas, 2016–17

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