scholarly journals Effects of cyanobacterial-driven pH increases on sediment nutrient fluxes and coupled nitrification-denitrification in a shallow fresh water estuary

2012 ◽  
Vol 9 (7) ◽  
pp. 2697-2710 ◽  
Author(s):  
Y. Gao ◽  
J. C. Cornwell ◽  
D. K. Stoecker ◽  
M. S. Owens
Keyword(s):  
Oxygen Consumption ◽  
Pore Water ◽  
Soluble Reactive Phosphorus ◽  
Inorganic Phosphorus ◽  
Cyanobacterial Blooms ◽  
Ph Effects ◽  
Overlying Water ◽  
High Ph ◽  
Total Ammonium ◽  
Water Ecosystems

Abstract. Summer cyanobacterial blooms caused an elevation in pH (9 to ~10.5) that lasted for weeks in the shallow and tidal-fresh region of the Sassafras River, a tributary of Chesapeake Bay (USA). Elevated pH promoted desorption of sedimentary inorganic phosphorus and facilitated conversion of ammonium (NH4+) to ammonia (NH3). In this study, we investigated pH effects on exchangeable NH4+ desorption, pore water diffusion and the flux rates of NH4+, soluble reactive phosphorus (SRP) and nitrate (NO3−), nitrification, denitrification, and oxygen consumption. Elevated pH enhanced desorption of exchangeable NH4+ through NH3 formation from both pore water and adsorbed NH4+ pools. Progressive penetration of high pH from the overlying water into sediment promoted the mobility of SRP and the release of total ammonium (NH4+ and NH3) into the pore water. At elevated pH levels, high sediment-water effluxes of SRP and total ammonium were associated with reduction of nitrification, denitrification and oxygen consumption rates. Alkaline pH and the toxicity of NH3 may inhibit nitrification in the thin aerobic zone, simultaneously constraining coupled nitrification–denitrification with limited NO3− supply and high pH penetration into the anaerobic zone. Geochemical feedbacks to pH elevation, such as enhancement of dissolved nutrient effluxes and reduction in N2 loss via denitrification, may enhance the persistence of cyanobacterial blooms in shallow water ecosystems.

scholarly journals Effects of cyanobacterial-driven pH increases on sediment nutrient fluxes and coupled nitrification-denitrification in a shallow fresh water estuary

2012 ◽  
Vol 9 (1) ◽  
pp. 1161-1198 ◽  
Author(s):  
Y. Gao ◽  
J. C. Cornwell ◽  
D. K. Stoecker ◽  
M. S. Owens
Keyword(s):  
Oxygen Consumption ◽  
Pore Water ◽  
Soluble Reactive Phosphorus ◽  
Inorganic Phosphorus ◽  
Cyanobacterial Blooms ◽  
Ph Effects ◽  
Overlying Water ◽  
High Ph ◽  
Total Ammonium ◽  
Ph Elevation

Abstract. Summer cyanobacterial blooms caused an elevation in pH (9 to ~10.5) that lasted for weeks in the shallow and tidal-fresh region of the Sassafras River, a tributary of Chesapeake Bay (USA). Elevated pH promoted desorption of sedimentary inorganic phosphorus and facilitated conversion of ammonium (NH4+) to ammonia (NH3). In this study, we investigated pH effects on exchangeable NH4+ desorption, nutrient pore water diffusion and flux rates of NH4+, soluble reactive phosphorus (SRP), nitrate (NO3–), nitrification, denitrification, and oxygen consumption. pH elevation enhanced the desorption of exchangeable NH4+ because of NH3 formation from both pore water and adsorbed NH4+ pools. Progressive penetration of high pH from the overlying water into sediment promoted the release of SRP and total ammonium (NH4+ and NH3) into pore water. At elevated pH, high sediment-water effluxes of SRP and total ammonium were associated with reduction in nitrification, denitrification and oxygen consumption rates. Alkaline pH and the toxicity of NH3 may inhibit nitrification in the thin aerobic zone, simultaneously constraining coupled nitrification-denitrification with limited NO3– supply and high pH penetration into the anaerobic zone. Geochemical feedbacks to pH elevation, such as enhancement of dissolved nutrient effluxes and reduction in N2 loss via denitrification, may be responsible for the persistence of cyanobacterial blooms in shallow water ecosystems.

Phosphorus Release Processes in Nearshore Southern Lake Michigan

1986 ◽  
Vol 43 (6) ◽  
pp. 1201-1207 ◽  
Author(s):  
Michael A. Quigley ◽  
John A. Robbins
Keyword(s):  
Pore Water ◽  
Lake Michigan ◽  
Sampling Site ◽  
Soluble Reactive Phosphorus ◽  
Fine Sand ◽  
Phosphorus Release ◽  
Fickian Diffusion ◽  
Phosphorus Cycle ◽  
Release Rates ◽  
Overlying Water

We determined soluble reactive phosphorus (SRP) release rates from intact, medium-fine sand cores obtained from an 11-m-deep sampling site in nearshore Lake Michigan during July–October 1980. Mean SRP release ranged from 0.17 ± 0.03 (SE) to 0.57 ± 0.04 mg PO4-P∙m−2∙d−1. Pore water analysis indicated that, despite high dissolved oxygen concentrations in the uppermost 6 cm of sediment, SRP concentrations increased rapidly with depth throughout this zone. Moreover, a Fickian diffusion equation based on the SRP pore water gradient and physical sediment features predicted a release rate (1.12 mg PO4-P∙m−1∙d−1) that was 2–7 times higher than release rates measured from intact cores. Results suggest that nearshore sediments provide a ready pathway for the return of SRP to overlying water, and this process warrants inclusion in future conceptual models of Lake Michigan's phosphorus cycle.

scholarly journals Spatio-temporal Variation in Nutrient Profiles and Exchange Fluxes at the Sediment-Water Interface in Yuqiao Reservoir, China

2019 ◽  
Vol 16 (17) ◽  
pp. 3071 ◽  
Author(s):  
Wen ◽  
Wu ◽  
Yang ◽  
Jiang ◽  
Zhong
Keyword(s):  
Pore Water ◽  
Water Source ◽  
Water Soluble ◽  
Drinking Water Source ◽  
Eutrophic Lakes ◽  
Overlying Water ◽  
Total N ◽  
Yuqiao Reservoir ◽  
Nutrient Profiles ◽  
Main Component

Nutrients released from sediments have a significant influence on the water quality in eutrophic lakes and reservoirs. To clarify the internal nutrient load and provide reference for eutrophication control in Yuqiao Reservoir, a drinking water source reservoir in China, pore water profiles and sediment core incubation experiments were conducted. The nutrients in the water (soluble reactive P (SRP), nitrate-N (NO3−-N), nitrite-N (NO2−-N), and ammonium-N (NH4+-N)) and in the sediments (total N (TN), total P (TP) and total organic carbon (TOC)) were quantified. The results show that NH4+-N was the main component of inorganic N in the pore water. NH4+-N and SRP were higher in the pore water than in the overlying water, and the concentration gradient indicated a diffusion potential from the sediment to the overlying water. The NH4+-N, NO3−-N, and SRP fluxes showed significant differences amongst the seasons. The NH4+-N and SRP fluxes were significantly higher in the summer than in other seasons, while NO3−-N was higher in the autumn. The sediment generally acted as a source of NH4+-N and SRP and as a sink for NO3−-N and NO2−-N. The sediments release 1133.15 and 92.46 tons of N and P, respectively, to the overlying water each year.

scholarly journals Hydrochemistry of sediment pore water in the Bratsk reservoir (Baikal region, Russia)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
V. I. Poletaeva ◽  
E. N. Tirskikh ◽  
M. V. Pastukhov
Keyword(s):  
Pore Water ◽  
Ionic Composition ◽  
Water System ◽  
Water Reservoir ◽  
Environmental Parameters ◽  
Water Area ◽  
Pore Waters ◽  
Overlying Water ◽  
Major Ion ◽  
Bratsk Reservoir

AbstractThis study aimed to identify the factors responsible for the major ion composition of pore water from the bottom sediments of the Bratsk water reservoir, which is part of the largest freshwater Baikal-Angara water system. In the Bratsk reservoir, the overlying water was characterized as HCO3–Ca–Mg type with the mineralization ranging between 101.2 and 127.7 mg L−1 and pore water was characterized as HCO3–SO4–Ca, SO4–Cl–Ca–Mg and mixed water types, which had mineralization varying from 165.9 to 4608.1 mg L−1. The ionic composition of pore waters varied both along the sediment depth profile and across the water area. In pore water, the difference between the highest and lowest values was remarkably large: 5.1 times for K+, 13 times for Mg2+, 16 times for HCO3−, 20 times for Ca2+, 23 times for Na+, 80 times for SO42−, 105 times for Cl−. Such variability at different sites of the reservoir was due to the interrelation between major ion concentrations in the pore water and environmental parameters. The major factor responsible for pore water chemistry was the dissolution of sediment-forming material coming from various geochemical provinces. In the south part of the reservoir, Cl−, Na+ and SO42− concentrations may significantly increase in pore water due to the effect of subaqueous flow of highly mineralized groundwater.

scholarly journals Potential for Mycorrhizae-Assisted Phytoremediation of Phosphorus for Improved Water Quality

2020 ◽  
Vol 18 (1) ◽  
pp. 7
Author(s):  
Jessica A. Rubin ◽  
Josef H. Görres
Keyword(s):  
Water Quality ◽  
Animal Health ◽  
Phosphorus Uptake ◽  
Agricultural Practices ◽  
Fold Increase ◽  
Landscape Patterns ◽  
Cyanobacterial Blooms ◽  
Terrestrial Plants ◽  
Source Reduction ◽  
Water Ecosystems

During this 6th Great Extinction, freshwater quality is imperiled by upland terrestrial practices. Phosphorus, a macronutrient critical for life, can be a concerning contaminant when excessively present in waterways due to its stimulation of algal and cyanobacterial blooms, with consequences for ecosystem functioning, water use, and human and animal health. Landscape patterns from residential, industrial and agricultural practices release phosphorus at alarming rates and concentrations threaten watershed communities. In an effort to reconcile the anthropogenic effects of phosphorus pollution, several strategies are available to land managers. These include source reduction, contamination event prevention and interception. A total of 80% of terrestrial plants host mycorrhizae which facilitate increased phosphorus uptake and thus removal from soil and water. This symbiotic relationship between fungi and plants facilitates a several-fold increase in phosphorus uptake. It is surprising how little this relationship has been encouraged to mitigate phosphorus for water quality improvement. This paper explores how facilitating this symbiosis in different landscape and land-use contexts can help reduce the application of fertility amendments, prevent non-point source leaching and erosion, and intercept remineralized phosphorus before it enters surface water ecosystems. This literature survey offers promising insights into how mycorrhizae can aid ecological restoration to reconcile humans’ damage to Earth’s freshwater. We also identify areas where research is needed.

scholarly journals Warming increases carbon and nutrient fluxes from sediments in streams across land use

2013 ◽  
Vol 10 (2) ◽  
pp. 1193-1207 ◽  
Author(s):  
S.-W. Duan ◽  
S. S. Kaushal
Keyword(s):  
Land Use ◽  
Organic Matter ◽  
Land Use Change ◽  
Sulfate Reduction ◽  
Organic Matter Content ◽  
Soluble Reactive Phosphorus ◽  
Overlying Water ◽  
Sediment Fluxes ◽  
Urban Sites

Abstract. Rising water temperatures due to climate and land use change can accelerate biogeochemical fluxes from sediments to streams. We investigated impacts of increased streamwater temperatures on sediment fluxes of dissolved organic carbon (DOC), nitrate, soluble reactive phosphorus (SRP) and sulfate. Experiments were conducted at 8 long-term monitoring sites across land use (forest, agricultural, suburban, and urban) at the Baltimore Ecosystem Study Long-Term Ecological Research (LTER) site in the Chesapeake Bay watershed. Over 20 yr of routine water temperature data showed substantial variation across seasons and years. Lab incubations of sediment and overlying water were conducted at 4 temperatures (4 °C, 15 °C, 25 °C, and 35 °C) for 48 h. Results indicated: (1) warming significantly increased sediment DOC fluxes to overlying water across land use but decreased DOC quality via increases in the humic-like to protein-like fractions, (2) warming consistently increased SRP fluxes from sediments to overlying water across land use, (3) warming increased sulfate fluxes from sediments to overlying water at rural/suburban sites but decreased sulfate fluxes at some urban sites likely due to sulfate reduction, and (4) nitrate fluxes showed an increasing trend with temperature at some forest and urban sites but with larger variability than SRP. Sediment fluxes of nitrate, SRP and sulfate were strongly related to watershed urbanization and organic matter content. Using relationships of sediment fluxes with temperature, we estimate a 5 °C warming would increase mean sediment fluxes of SRP, DOC and nitrate-N across streams by 0.27–1.37 g m−2 yr−1, 0.03–0.14 kg m−2 yr−1, and 0.001–0.06 kg m−2 yr−1. Understanding warming impacts on coupled biogeochemical cycles in streams (e.g., organic matter mineralization, P sorption, nitrification, denitrification, and sulfate reduction) is critical for forecasting shifts in carbon and nutrient loads in response to interactive impacts of climate and land use change.

Sediment metabolism in a transitional continental - marine area: The Albufera of Majorca (Balearic Islands, Spain)

1995 ◽  
Vol 46 (1) ◽  
pp. 45 ◽  
Author(s):  
P Lopez ◽  
M Vidal ◽  
X Lluch ◽  
JA Morgui
Keyword(s):  
Oxygen Consumption ◽  
Pore Water ◽  
Respiratory Quotient ◽  
Nutrient Dynamics ◽  
Anaerobic Respiration ◽  
Ammonium Phosphate ◽  
Nutrient Concentrations ◽  
Co2 Efflux ◽  
Marine Areas ◽  
Diffusive Fluxes

The concentrations of nutrients in sediment pore water and the fluxes of nutrients at the water-sediment interface were measured in a channel that joins continental and marine areas in the Albufera of Majorca in order to evaluate the role of sediments in the nutrient dynamics in this system. Upstream, surficial pore water presented lower values of Eh, which became negative in summer, whereas downstream Eh remained positive. Nutrient concentrations were especially high upstream, reaching 1000 mol L-1 of NH4 and 75 μmol L-1 of PO4 during summer. In summer, measured fluxes showed intense respiration upstream, with an oxygen consumption of 130 mg m-2 h-1 and a respiratory quotient near 4, which indicates dominance of anaerobic respiration. Total CO2 efflux and nutrient fluxes were also high, reaching 30.50 mmol m-2 h-1 for CO2, >2000 μmol m-2 h-1 for NH4 and 58 μmol m-2 h-1 for PO4. A substantial amount of the total CO2 efflux (14 mmol m-2 h-1) was due to calcium carbonate redissolution. Downstream, oxygen consumption, respiratory quotient and ammonium fluxes were lower (around 70 mg m-2 h-1, between 2 and 3, and <20 μmol m-2 h-1, respectively), which indicates a moderate rate of decomposition activity and suggests denitrification as the main respiratoy process. Differences between fluxes measured 'in situ' and those calculated from pore-water concentrations indicated non-diffusive fluxes upstream and suggest substantial denitrifying activity downstream. Extra keywords: benthic chambers, sediment fluxes, pore water, ammonium, phosphate.

scholarly journals Spatial and Seasonal Distribution and Transportation of Different Forms of Phosphorus in the Middle Reaches of the Yarlung Zangbo River

Water ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1858 ◽  
Author(s):  
Xiaolong Cheng ◽  
Yanan Huang ◽  
Xunchi Pu ◽  
Ruidong An ◽  
Wendian Huang ◽  
...  
Keyword(s):  
Surface Sediments ◽  
Organic Phosphorus ◽  
Nutrient Status ◽  
Inorganic Phosphorus ◽  
Research Area ◽  
Phosphorus Concentration ◽  
Wet Season ◽  
Overlying Water ◽  
Total Phosphorus Concentration ◽  
Yarlung Zangbo River

The Yarlung Zangbo River basin ecosystem is fragile. The distribution and transportation of phosphorus is of great significance for aquatic environmental protection and ecological security. The sequential extraction method and molybdenum antimony anti-spectrophotometry were used to measure the concentrations of different forms of phosphorus in the surface sediments from 15 sampling sites along the middle reaches of the Yarlung Zangbo River and its tributaries. The results show that the total phosphorus concentration in the surface sediments is 194.0~540.7 mg/kg, which is mainly composed of inorganic phosphorus. The concentrations of various phosphorus forms ranked as calcium-bound phosphorus (355.6 ± 86.0 mg/kg) > soluble phosphorus (15.9 ± 10.0 mg/kg) > iron-bound phosphorus (12.4 ± 12.3 mg/kg) > organic phosphorus (9.6 ± 6.1 mg/kg) > occluded phosphorus (9.2 ± 3.8 mg/kg) > aluminum-bound phosphorus (5.4 ± 2.3 mg/kg). On the whole, phosphorus concentration is greater in wet season than dry season. Regarding the spatial distribution characteristics, there are great disparities in the different forms of phosphorus in the middle reaches of the Yarlung Zangbo River. Comprehensive analysis shows that phosphorus of this area is mainly self-generated, and concentration of bioavailable phosphorus is small, demonstrating there will not be a large release. We also drew a “specific triangle” of the different forms of phosphorus concentrations in the research area and defined the “α” angle to determine the nutrient status of the overlying water quickly and effectively. Finally, phosphorus flux of the mainstream was estimated. This research may provide information on the phosphorus of Plateau Rivers.

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