scholarly journals Exploring river nitrogen and phosphorus loading and export to global coastal waters in the Shared Socio-economic pathways

2022 ◽  
Vol 72 ◽  
pp. 102426
Author(s):  
A.H.W. Beusen ◽  
J.C. Doelman ◽  
L.P.H. Van Beek ◽  
P.J.T.M. Van Puijenbroek ◽  
J.M. Mogollón ◽  
...  
Keyword(s):  
Coastal Waters ◽  
Phosphorus Loading ◽  
Nitrogen And Phosphorus

Contemporary issues in watershed and water quality modeling for eutrophication control

1998 ◽  
Vol 37 (3) ◽  
pp. 93-102
Author(s):  
Robert V. Thomann ◽  
Lewis C. Linker
Keyword(s):  
Coastal Waters ◽  
Water Quality Modeling ◽  
Significant Decline ◽  
Suspension Feeding ◽  
Watershed Model ◽  
Nitrogen And Phosphorus ◽  
Overlying Water ◽  
Chesapeake Bay Watershed ◽  
Eutrophication Control ◽  
Quality Modeling

Three issues are discussed: controllability of nonpoint nutrient loadings using watershed models; the sometimes counter intuitive results from eutrophication models from nutrient controls for coastal waters; and the potential significant interaction of improvement in habitat for suspension feeding bivalves. For the Chesapeake Bay watershed model, and for Limit of Technology (LOT) controls, a 16% and 45% reduction in nitrogen and phosphorus, respectively, is calculated. For the Bay, it is concluded that removal of phosphorus only is less effective than nitrogen in improving bottom water DO because of differential transport of nitrogen downstream. For the Delaware estuary, a significant decline in phytoplankton chlorophyll has been observed in the absence of any nutrient controls but in the presence of improved DO. A simple model is offered that hypothesized an increase in benthic bivalve filtration of overlying water as a result of improvement in DO.

Effect of Nitrogen and Phosphorus Loading in Coastal Plain Blackwater Rivers

2001 ◽  
Vol 16 (3) ◽  
pp. 455-464 ◽  
Author(s):  
Michael A Malin ◽  
Lawrence B Cahoon ◽  
Douglas C Parsons ◽  
Scott H Ensign
Keyword(s):  
Coastal Plain ◽  
Phosphorus Loading ◽  
Nitrogen And Phosphorus ◽  
Blackwater Rivers

scholarly journals The capability of organic matter decomposition and nutrient uptake in coastal waters of Ca Na bay, Ninh Thuan province

2019 ◽  
Vol 19 (4A) ◽  
pp. 103-113
Author(s):  
Hoang Trung Du ◽  
Nguyen Trinh Duc Hieu
Keyword(s):  
Organic Matter ◽  
Nutrient Uptake ◽  
Coastal Waters ◽  
Rainy Season ◽  
Laboratory Experiments ◽  
Dry Season ◽  
Organic Matter Decomposition ◽  
Environmental Capacity ◽  
Nitrogen And Phosphorus ◽  
Organic Decomposition

This paper focuses on the capability of organic matter decomposition and inorganic nutrient uptake in the coastal waters of Ca Na bay (Ninh Thuan province) in October, 2018 (the rainy season) and May, 2019 (the dry season).  The results of laboratory experiments on organic decomposition, photosynthesis and nutrient uptake showed that the BODgh and the average values of k- decay rate in coastal waters of the surveyed area are higher in the rainy season compared with the dry season, with the average BODgh values of 5.474 mgO2/l and 4.768 mgO2/l respectively, and the corresponding k-values of 0.183 day-1 and 0.143 day-1. Howver, the half-life decay of organic matter is lower in the rainy season than in the dry season, with the corresponding values of 5.110 days and 5.571 days. In the studied area, the photosynthesis of phytoplankton strongly absorbs nitrate (NO3-), followed by ammonium (NH4+) and phosphate (PO43-). The capability of nutrient uptake for nitrogen and phosphorus components was 9.17 mgN/m3/hour and 0.92 mgP/m3/hour, respectively in the dry season; and 7.31 mgN/m3/hour and 0.63 mgP/m3/hour in the rainy season. The results of the study are favorable condition for calculating the environmental capacity in the coastal waters of Ca Na bay in the future.

scholarly journals Remediation of Nitrogen and Phosphorus from Nursery Runoff during the Spring via Free Water Surface Constructed Wetlands

2010 ◽  
Vol 28 (4) ◽  
pp. 209-217 ◽  
Author(s):  
Sarah A. White ◽  
Milton D. Taylor ◽  
Stewart L. Chandler ◽  
Ted Whitwell ◽  
Stephen J. Klaine
Keyword(s):  
Water Quality ◽  
Water Surface ◽  
Nutrient Loading ◽  
Free Water ◽  
Surface Water Quality ◽  
Phosphorus Loading ◽  
Late Winter ◽  
Nitrogen And Phosphorus ◽  
Free Water Surface ◽  
The Impact

Abstract Agricultural operations face increasing pressure to remediate runoff to reduce deterioration of surface water quality. Some nursery operations use free water surface constructed wetland systems (CWSs) to remediate nutrient-rich runoff. Our objectives were twofold, first to examine the impact of two hydraulic retention times (HRT, 3.5 and 5.5 day) on CWS performance, and second to determine if increased nutrient loading from internal CWS and nursery sources during the spring contributed to nutrient export in excess of regulatory limits. We quantified nutrient loading and removal efficiency in a free water surface CWS from late winter through late spring over three years and monitored various water quality parameters. Total nitrogen in runoff was reduced from 20.6 ± 2.8 mg·liter−1 (ppm) to 4.1 ± 1.3 mg·liter−1 (ppm) nitrogen after CWS treatment. Phosphorus dynamics in the CWS were more variable and unlike nitrogen dynamics were not consistently influenced by water temperature and hydraulic loading rate. Phosphorus concentrations were reduced from 1.7 ± 0.8 mg·liter−1 (ppm) PO4-P in influent to 1.2 ± 0.6 mg·liter−1 (ppm) PO4-P in CWS effluent, but substantial variability existed among years in both phosphorus loading and removal rates. The CWS was able to efficiently remediate nitrogen even under high spring loading rates.

An integrated approach in a municipal WWTP: anaerobic codigestion of sludge with organic waste and nutrient removal from supernatant

2008 ◽  
Vol 58 (3) ◽  
pp. 669-676 ◽  
Author(s):  
S. Caffaz ◽  
E. Bettazzi ◽  
D. Scaglione ◽  
C. Lubello
Keyword(s):  
Nitrogen Removal ◽  
Nutrient Removal ◽  
Organic Waste ◽  
Biogas Production ◽  
Removal Rate ◽  
Integrated Approach ◽  
Phosphate Removal ◽  
Phosphorus Loading ◽  
Nitrogen And Phosphorus ◽  
Anaerobic Codigestion

Co-digestion appears to be an interesting solution to increase the biogas production of poorly performing under-loaded digesters of waste activated sludge. In the Florence WWTP anaerobic codigestion could increase nitrogen and phosphorus loading rates and thus lower the nutrient removal efficiency. In order to develop an integrated solution to upgrade the Florence WWTP, the different process units were tested in experimental plants. Anaerobic codigestion with source-collected organic solid waste in a pilot-scale bioreactor showed an increase of GPR from 0.15 to 0.45 Nl biogas/l/d with 23% of organic waste loaded. Autotrophic nitrogen removal was carried out in two lab-scale pilot plants which were fed with a real anaerobic supernatant after phosphate removal via struvite formation. The nitritation MBBR has been working for one year at steady-state conditions with a perfect nitrite/ammonium ratio equal to 1:1. Anammox biomass enrichment was performed in a suspended biomass SBR and the specific nitrogen removal rate increased from 1.7 to 58 gN/kgVSS/d in 375 days.

scholarly journals Assessing the Nitrogen and Phosphorus Loading in the Alabama (USA) River Basin Using PLOAD Model

2013 ◽  
Vol 6 ◽  
pp. ASWR.S10548 ◽  
Author(s):  
Dev P. Gurung ◽  
Leonard J.M. Githinji ◽  
Ramble O. Ankumah
Keyword(s):  
Environmental Protection ◽  
River Basin ◽  
Environmental Protection Agency ◽  
Phosphorus Loading ◽  
Field Sampling ◽  
Protection Agency ◽  
Nitrogen And Phosphorus ◽  
Pollutant Loading ◽  
The Us ◽  
Rivers And Streams

Pollutant loadings in two watersheds, Mulberry and Catoma were assessed using the pollutant loading (PLOAD) model and model results were compared with those obtained from field sampling followed by laboratory analysis. The PLOAD model was used to determine water pollutants including total nitrogen (TN), total phosphorus (TP), orthophosphate (PO43-), nitrite (NO2–) and nitrate (NO3–) in two watersheds, Mulberry and Catoma that are part of the Alabama River Basin. Results revealed that both Mulberry and Catoma watersheds had TN and TP values that exceeded the US Environmental Protection Agency (EPA) limits set for rivers and streams. The TN and TP values were in the range of hypertrophic for lakes, and eutrophic for rivers. The PLOAD model results were in agreement with analytical results. We conclude that PLOAD is a valid model for determining pollutant loading in watersheds and provides a relatively faster and cheaper method of assessing impairment of watershed bodies compared to conventional methods.

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