scholarly journals Concentrations, Loads, and Associated Trends of Nutrients Entering the Sacramento–San Joaquin Delta, California

2021 ◽  
Vol 19 (4) ◽  
Author(s):  
Dina Saleh ◽  
◽  
Joseph Domagalski ◽  
Keyword(s):  
Water Quality ◽  
Wastewater Treatment ◽  
Inorganic Nitrogen ◽  
Sacramento River ◽  
Quality Data ◽  
Nitrogen And Phosphorus ◽  
Molar Ratios ◽  
San Joaquin River ◽  
Nitrogen Inputs ◽  
River Site

Statistical modeling of water-quality data collected at the Sacramento River at Freeport and San Joaquin River near Vernalis, California, USA, was used to examine trends in concentrations and loads of various forms of dissolved and particulate nitrogen and phosphorus that entered the Sacramento–San Joaquin River Delta (Delta) from upstream sources between 1970 and 2019. Ammonium concentrations and loads decreased at the Sacramento River site from the mid-1970s through 1990 because of the consolidation of wastewater treatment and continuously reduced from the mid-1970s to 2019 at the San Joaquin River site. Current ammonium concentrations are mostly below 4 µM (0.056 mg N L–1) at both sites, a concentration above which reductions in phytoplankton productivity or changes in algal species composition may occur. The Sacramento River at Freeport site is located upstream of the Sacramento Regional County Sanitation District’s treatment facility’s discharge point; nutrient water quality there is representative of upstream sources. Inorganic nitrogen (nitrate plus ammonium) concentrations and loading differed at both sites. At the Sacramento River location, concentrations decrease in the summer agricultural season, reducing the molar ratios of nitrogen to phosphorus. In contrast, inorganic nitrogen concentrations increase in the San Joaquin River during the agricultural season as a result of irrigation runoff, increasing the molar ratio of nitrogen to phosphorus. This increase suggests a possible nitrogen limitation in the northern Delta and a phosphorus limitation in the southern Delta, as indicated by the molar ratios of bioavailable nitrogen to bioavailable phosphorus. Planned upgrades to the Sacramento Regional Wastewater Treatment Plant (SRWTP) will reduce inorganic nitrogen inputs to the northern Delta. Consequently, the supply of bioavailable nitrogen throughout the upper estuary should diminish. Source modeling of nitrogen and phosphorus identifies agriculture, atmospheric deposition, and wastewater effluent as sources of total nitrogen in the Central Valley. In contrast, geologic sources, agriculture, and wastewater discharge are the primary sources of phosphorus.

scholarly journals Nitrogen and Phosphorus Budget for a Deep Tropical Reservoir of the Brazilian Savannah

Water ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1205 ◽  
Author(s):  
Jackeline do S. B. Barbosa ◽  
Valéria R. Bellotto ◽  
Damiana B. da Silva ◽  
Thiago B. Lima
Keyword(s):  
Wastewater Treatment ◽  
Nutrient Dynamics ◽  
Wastewater Treatment Plants ◽  
Organic Phosphorus ◽  
Inorganic Nitrogen ◽  
Nutrient Input ◽  
Nitrogen And Phosphorus ◽  
Tropical Reservoir ◽  
Artificial Lake ◽  
Total Organic Nitrogen

This research investigated the source and fate of different chemical species of N and P on a deep tropical urban reservoir, the artificial Lake Paranoá, located in the city of Brasilia (Brazil). To determine an N and P budget, nutrient input from the external load (four main tributaries and two wastewater treatment plants), internal load (from sediment) and nutrient output (from a downstream dam) were estimated empirically. Nutrient storage was evaluated in two compartments: water column and sediment. Nutrient input from the tributaries varied by season presenting higher loads in the wet season, especially N. Nutrient budgets in our study indicated that Lake Paranoá retained dissolved inorganic nitrogen (DIN), PO43−-P, total organic phosphorus (TOP) and exported total organic nitrogen (TON), both on a seasonal and annual scale. Surface sediment is the major storage compartment for both N and P. These results show the pressing need for action to reduce the P outcome charges, mainly, from the wastewater treatment plants. The data here presented contributes to the recognition of this situation and to a better comprehension of these nutrient dynamics, as well as an understanding of the behavior of tropical deep-water reservoirs. This can help to promote more effective management, providing a reference for other similar systems.

Post-fire water-quality response in the western United States

2018 ◽  
Vol 27 (3) ◽  
pp. 203 ◽  
Author(s):  
Ashley J. Rust ◽  
Terri S. Hogue ◽  
Samuel Saxe ◽  
John McCray
Keyword(s):  
United States ◽  
Water Quality ◽  
Stream Water ◽  
Western United States ◽  
Change Point Analysis ◽  
Quality Data ◽  
Stream Water Quality ◽  
Nitrogen And Phosphorus ◽  
Water Quality Data ◽  
Quality Response

Wildfires are increasing in size and severity in forested landscapes across the Western United States. Not only do fires alter land surfaces, but they also affect the surface water quality in downstream systems. Previous studies of individual fires have observed an increase in various forms of nutrients, ions, sediments and metals in stream water for different post-fire time periods. In this research, data were compiled for over 24 000 fires across the western United States to evaluate post-fire water-quality response. The database included millions of water-quality data points downstream of these fires, and was synthesised along with geophysical data from each burned watershed. Data from 159 fires in 153 burned watersheds were used to identify common water-quality response during the first 5 years after a fire. Within this large dataset, a subset of seven fires was examined further to identify trends in water-quality response. Change-point analysis was used to identify moments in the post-fire water-quality data where significant shifts in analyte concentrations occurred. Evaluating individual fires revealed strong initial increases or decreases in concentrations, depending on the analyte, that are masked when averaged over 5 years. Evidence from this analysis shows significant increases in nutrient flux (different forms of nitrogen and phosphorus), major-ion flux and metal concentrations are the most common changes in stream water quality within the first 5 years after fire. Dissolved constituents of ions and metals tended to decrease in concentration 5 years after fire whereas particulate matter concentration continued to increase. Assembling this unique and extensive dataset provided the opportunity to determine the most common post-fire water-quality changes in the large and diverse Western USA. Results from this study could inform studies in other parts of the world, will help parameterise and validate post-fire water-quality models, and assist communities affected by wildfire to anticipate changes to their water quality.

scholarly journals Deterioration in the water quality of an urbanised estuary with recommendations for improvement

Water SA ◽  
2019 ◽  
Vol 45 (1 January) ◽  
Author(s):  
Adams JB ◽  
L Pretorius ◽  
GC Snow
Keyword(s):  
Water Quality ◽  
Inorganic Nitrogen ◽  
Vertical Mixing ◽  
Primary Source ◽  
Inorganic Phosphorus ◽  
Quality Data ◽  
Spatial And Temporal Variability ◽  
Phytoplankton Blooms ◽  
Water Quality Data

Water quality characteristics of the heavily urbanised and industrialised Swartkops River and Estuary in the Eastern Cape have been the focus of several studies since the 1970s. Overloaded and poorly maintained wastewater treatment works (WWTWs), polluted stormwater runoff and solid waste have all contributed to the deterioration in the water quality of the river and estuary. The objective of this study was to determine the current water quality status of the Swartkops Estuary, by investigating spatial and temporal variability in physico-chemical parameters and phytoplankton biomass and where possiblerelate this to historical water quality data. The present study found evidence suggesting that water is not flushed as efficiently from the upper reaches of the estuary as was previously recorded. Reduced vertical mixing results in strong stratification and persistent eutrophic conditions with phytoplankton blooms (> 20 μg chl a·L−1), extending from the middle reaches to the tidal head of the estuary. The Motherwell Canal was and still is a major source of nitrogen (particularly ammonium) to the estuary, but the Swartkops River is the primary source of phosphorus with excessive inputs from the cumulative effectof three WWTWs upstream. An analysis of historical water quality data in the Swartkops Estuary (1995 to 2013) shows that all recorded dissolved inorganic phosphorus measurements were classified as hypertrophic (> 0.1 mg P·L−1), whereas 41% of dissolved inorganic nitrogen measurements were either mesotrophic or eutrophic. If nutrient removal methods at the three WWTWs were improved and urban runoff into the Motherwell Canal better managed, it is likely that persistent phytoplankton blooms and health risks associated with eutrophication could be reduced.

Influence of climate,geology and humans on spatial and temporal nutrient geochemistry in the subtropical Richmond River catchment, Australia

2001 ◽  
Vol 52 (2) ◽  
pp. 235 ◽  
Author(s):  
Lester J. McKee ◽  
Bradley D. Eyre ◽  
Shahadat Hossain ◽  
Peter R. Pepperell
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Agricultural Land ◽  
Anthropogenic Impacts ◽  
Inorganic Nitrogen ◽  
Point Sources ◽  
Nutrient Concentrations ◽  
Wet Season ◽  
Nitrogen And Phosphorus ◽  
River Catchment

Water quality was monitored on a spatial and temporal basis in the subtropical Richmond River catchment over two years. Nutrient concentrations varied seasonally in a complex manner with highest concentrations (maximum =3110 µg N L – 1 and 572 µg P L –1 ) associated with floods. However, median (444 µg N L – 1 and 55 µg P L – 1 ) concentrations were relatively low compared with other parts of the world. The forms of nitrogen and phosphorus in streams varied seasonally, with greater proportions of inorganic nitrogen and phosphorus during the wet season. Minimum nutrient concentrations were found 2—3 months after flood discharge. With the onset of the dry season, concentration increases were attributed to point sources and low river discharge. There were statistically significant relationships between geology and water quality and nutrient concentrations increased downstream and were significantly related to population density and dairy farming. In spite of varying geology and naturally higher phosphorus in soils and rocks in parts of the catchment, anthropogenic impacts had the greatest effects on water quality in the Richmond River catchment. Rainfall quality also appeared to be related both spatially and seasonally to human activity. Although the responses of the subtropical Richmond River catchment to changes in land use are similar to those of temperate systems of North America and Europe, the seasonal patterns appear to be more complex and perhaps typical of subtropical catchments dominated by agricultural land use.

scholarly journals Spatial and Long-Term Temporal Changes in Water Quality Dynamics of the Tonle Sap Ecosystem

Water ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2059
Author(s):  
Savoeurn Soum ◽  
Peng Bun Ngor ◽  
Thomas E. Dilts ◽  
Sapana Lohani ◽  
Suzanne Kelson ◽  
...  
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Water Level ◽  
Inorganic Nitrogen ◽  
Flood Pulse ◽  
Nutrient Ratios ◽  
Nitrogen And Phosphorus ◽  
Watershed Land Use ◽  
Tonle Sap

Tonle Sap lake-river floodplain ecosystem (TSE) is one of the world’s most productive freshwater systems. Changes in hydrology, climate, population density, and land use influence water quality in this system. We investigated long term water quality dynamics (22 years) in space and time and identified potential changes in nutrient limitation based on nutrient ratios of inorganic nitrogen and phosphorus. Water quality was assessed at five sites highlighting the dynamics in wet and dry seasons. Predictors of water quality included watershed land use, climate, population, and water level. Most water quality parameters varied across TSE, except pH and nitrate that remained constant at all sites. In the last decade, there is a change in the chemical nutrient ratio suggesting that nitrogen may be the primary limiting nutrient across the system. Water quality was strongly affected by development in the watershed i.e., flooded forest loss, climatic variation, population growth, and change in water level. Seasonal variations of water quality constituents were driven by precipitation and hydrology, notably the Mekong’s distinct seasonal flood pulse.

scholarly journals Stoichiometry of carbon, nitrogen and phosphorus in wastewater from Romania

2021 ◽  
Vol 3 (2) ◽  
pp. 120-129
Author(s):  
Florinela Pirvu ◽  
◽  
Iuliana Paun ◽  
Marcela Niculescu ◽  
Vasile Ion Iancu ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Total Nitrogen ◽  
Inorganic Nitrogen ◽  
Sampling Point ◽  
Nitrogen And Phosphorus ◽  
Southeastern Part ◽  
Geographical Regions ◽  
Nitrogen Concentrations ◽  
Autumn And Winter ◽  
Very High

Water resources crisis can lead to a new concept of wastewater treatment. Wastewater cannot be considered waste but can be a renewable or non-renewable energy source. Nutrients from wastewater could be recycled and not disposed of. A circular economy can be created that can be based on the ability of algae to absorb and store nutrients: carbon (C), nitrogen (N) and phosphorus (P). This study investigates the stoichiometry between carbon, nitrogen and phosphorus in wastewater from three geographical regions of Romania. The concentrations of inorganic nitrogen, total nitrogen, total phosphorus, and total organic carbon were compared and evaluated. Three wastewater sampling points located in different areas were monitored, in the period 2013-2017 for the sampling point located in the central-northern part of the Romanian Plain and in the period 2015-2017 for the other two studied areas. The obtained results showed very high values of total nitrogen concentrations with values between 28.2 mg/L and 107.2 mg/L for the southeastern part of Romania. The values of the stoichiometric ratio’s C/N, C/P, N/P have varied over time with maximums in the autumn and winter seasons which indicates the existence of significant contamination of wastewater. It may be possible in the future to improve the performance of wastewater treatment by adjusting C, N, and P parameters.

scholarly journals Analysis on the Evolution Trend of Seawater Quality and Eutrophication in Tianjin Hangu Agricultural and Fishery Area from 2010 to 2019

2021 ◽  
Vol 245 ◽  
pp. 02024
Author(s):  
Yi Chen
Keyword(s):  
Water Quality ◽  
Pollution Control ◽  
Inorganic Nitrogen ◽  
The State ◽  
Dissolved Inorganic Nitrogen ◽  
Functional Area ◽  
Nitrogen And Phosphorus ◽  
Seawater Quality ◽  
Sea Area

Through the collection and analysis of COD, dissolved inorganic nitrogen (DIN) and active phosphate monitoring data in Tianjin Hangu Agricultural and fishery area from 2010 to 2019, this paper analyzed and studied the structure of nutrients and the state of eutrophication. The results show that in recent ten years, the water quality of Tianjin Hangu Agricultural and Fishery Area has basically met the water quality requirements of functional area, the regional nitrogen pollution has been suppressed, and the eutrophication index of sea area has shown a decreasing trend year by year, but the nitrogen and phosphorus nutrient structure is still in the state of “phosphorus restriction”. Pollution control of sea areas and conservation of aquatic germplasm resources are still urgent.

Using a GIS transfer model to evaluate pollutant loads in the Lake Kinneret watershed, Israel

2006 ◽  
Vol 53 (10) ◽  
pp. 75-82 ◽  
Author(s):  
D. Markel ◽  
F. Somma ◽  
B.M. Evans
Keyword(s):  
Water Quality ◽  
Wastewater Treatment ◽  
Point Source ◽  
Point Sources ◽  
Lake Kinneret ◽  
Anthropogenic Sources ◽  
Water Volume ◽  
Septic Systems ◽  
Transfer Model ◽  
Nitrogen And Phosphorus

Lake Kinneret (Sea of Galilee) is the only large surface water body in Israel, encompassing an area of 167 km2 and supplying some 30% of the country's fresh water. Pollution from anthropogenic sources and water abstraction for domestic and agricultural uses has long been threatening the water quality of the lake. Point-source pollution in the watershed has decreased drastically with the development of wastewater treatment. However, diffuse pollution from agricultural activities is still an unresolved issue. In this paper we present an application of AVGWLF (a GIS-based watershed load model) to the Lake Kinneret watershed. The model allows one to simulate daily stream flows and monthly sediment, nitrogen, and phosphorus loads discharged to the lake from the surrounding watershed. Results from simulations yield a satisfactory correspondence between simulated and measured daily water volume. Partition by source of total phosphorus delivered to the lake in the period of 2000–04 confirms the reduction in point source nutrient contribution due to improvement of wastewater treatment facilities in the area. Future management should focus on reduction of nutrients originating from septic systems (point sources) and pasture and cropland areas (diffuse sources). Results from simulations will enable watershed managers to prioritize effective management alternatives for protecting the water quality in the lake.

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