Column experiments show that cycling of both nitrogen and phosphorus is altered by dissolved organic carbon in river sediments

2021 ◽  
Author(s):  
Marc Stutter ◽  
Daniel Graeber ◽  
Gabriele Weigelhofer
Keyword(s):  
Organic Carbon ◽  
Nutrient Uptake ◽  
Inorganic Nitrogen ◽  
River Sediments ◽  
P Uptake ◽  
Controlled Study ◽  
Column Experiments ◽  
Nitrogen And Phosphorus ◽  
Organic C ◽  
Riparian Trees

<p>Since agriculture and wider development have altered simultaneously runoff, pollution and natural structures in catchments (e.g. wetlands, floodplains, soil drainage, riparian trees) aquatic ecosystems deviate from background concentrations of N and P, but also organic C (OC). Hence mechanistic studies coupling OC, N and P are needed and whilst data coupling OC:N is becoming more available and interpreted this is not yet the case for aquatic OC:P.  Column flow experiments (excluding light) allow preliminary controlled study of microbial biogeochemical processes in benthic sediments exposed to factorial nutrients (here +C, +NP, +CNP using simple dissolved substrates glucose, nitrate, and phosphate).</p><p>Based on the stoichiometric theory, we tested the hypothesis that bioavailable DOC will stimulate the heterotrophic uptake of soluble reactive P (SRP) and dissolved inorganic nitrogen in stream sediments. Glucose-C additions increased nutrient uptake, but also NP additions enhanced consumption of native and added OC. The effects of C addition were stronger on N than P uptake, presumably because labile C stimulated both assimilation and denitrification, while adsorption (unaffected by the presence or not of OC) formed a part of P uptake. Internal biogeochemical cycling lessened net nutrient uptake due to N and P recycling into dissolved organically-complexed forms (DOP and DON).</p><p>Simple column experiments point to mechanisms whereby availability of organic carbon can stimulate N and P sequestration in the bed of nutrient-polluted streams. This should promote further studies coupling OC with N and, especially P, towards better knowledge and ability to incorporate coupled macronutrient cycles into nutrient models and, potentially, ecosystem management.</p>

scholarly journals Available Dissolved Organic Carbon Alters Uptake and Recycling of Phosphorus and Nitrogen from River Sediments

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3321
Author(s):  
Marc Stutter ◽  
Daniel Graeber ◽  
Gabriele Weigelhofer
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Nutrient Uptake ◽  
Inorganic Nitrogen ◽  
River Sediments ◽  
Carbon Sources ◽  
P Uptake ◽  
Stream Sediments ◽  
Organic C ◽  
Flow Through

Concurrent with nutrient pollution, agriculture has significantly impacted the quantity, composition, and bioavailability of catchment-derived dissolved organic carbon (DOC) in stream ecosystems. Based on the stoichiometric theory, we tested the hypothesis that bioavailable DOC will stimulate the heterotrophic uptake of soluble reactive P (SRP) and inorganic nitrogen in stream sediments. In a simplified laboratory column flow-through study, we exposed stream sediments to additions of glucose, nitrate, and phosphate alone and in combination (+C, +NP, +CNP), and calculated gross and net changes in DOC and nutrients via a mass balance approach. Our results show that glucose-C increased nutrient uptake, but also that NP additions resulted in the enhanced consumption of both native and added organic C. The effects of C addition were stronger on N than P uptake, presumably because labile C stimulated both assimilation and denitrification, while part of the P uptake was due to adsorption. Internal cycling affected net nutrient uptake due to losses of dissolved organically-complexed P and N (DOP and DON). Overall, our study shows that increases in the stoichiometric availability of organic carbon can stimulate N and P sequestration in nutrient-polluted stream sediments. Future studies are required to assess the effects of complex organic carbon sources on nutrient uptake in stream sediments under different environmental conditions, and whether these stoichiometric relations are relevant for ecosystem management.

Carbon, nitrogen and phosphorus storage in subtropical seagrass meadows: examples from Florida Bay and Shark Bay

2012 ◽  
Vol 63 (11) ◽  
pp. 967 ◽  
Author(s):  
James W. Fourqurean ◽  
Gary A. Kendrick ◽  
Laurel S. Collins ◽  
Randolph M. Chambers ◽  
Mathew A. Vanderklift
Keyword(s):  
Organic Carbon ◽  
Carbon Content ◽  
Primary Productivity ◽  
Florida Bay ◽  
Organic Carbon Content ◽  
Nitrogen And Phosphorus ◽  
Organic C ◽  
Shark Bay ◽  
Seagrass Meadows ◽  
C Storage

Seagrass meadows in Florida Bay and Shark Bay contain substantial stores of both organic carbon and nutrients. Soils from both systems are predominantly calcium carbonate, with an average of 82.1% CaCO3 in Florida Bay compared with 71.3% in Shark Bay. Soils from Shark Bay had, on average, 21% higher organic carbon content and 35% higher phosphorus content than Florida Bay. Further, soils from Shark Bay had lower mean dry bulk density (0.78 ± 0.01 g mL–1) than those from Florida Bay (0.84 ± 0.02 mg mL–1). The most hypersaline regions of both bays had higher organic carbon content in surficial soils. Profiles of organic carbon and phosphorus from Florida Bay indicate that this system has experienced an increase in P delivery and primary productivity over the last century; in contrast, decreasing organic carbon and phosphorus with depth in the soil profiles in Shark Bay point to a decrease in phosphorus delivery and primary productivity over the last 1000 y. The total ecosystem stocks of stored organic C in Florida Bay averages 163.5 MgCorg ha–1, lower than the average of 243.0 MgCorg ha–1 for Shark Bay; but these values place Shark and Florida Bays among the global hotspots for organic C storage in coastal ecosystems.

Biological nitrogen and phosphorus removal in an anaerobic/anoxic sequencing batch reactor with separated biofilm nitrification

1994 ◽  
Vol 30 (6) ◽  
pp. 303-313 ◽  
Author(s):  
G. Bortone ◽  
F. Malaspina ◽  
L. Stante ◽  
A. Tilche
Keyword(s):  
Organic Carbon ◽  
Phosphorus Removal ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
P Uptake ◽  
Biofilm Reactor ◽  
Nitrogen And Phosphorus ◽  
Piggery Wastewater ◽  
Organic Carbon Oxidation ◽  
Biological Nitrogen

An Anaerobic/Anoxic Sequencing Batch Reactor (A/A SBR) with separated batch biofilm nitrification was tested for nutrient removal against a five step Anaerobic-anoxic/Oxic SBR (A/O SBR). Piggery wastewater, particularly challenging for its low COD/N ratio, was used as feed. After feeding, the A/A SBR ran under anaerobic conditions for organic carbon sequestering and phosphorus removal. A settling phase was allowed to separate an ammonia-rich supernatant to be nitrified in a external biofilm reactor. The nitrified effluent returned to the A/A SBR where nitrates were removed, being used as final electron acceptors for luxury P-uptake and organic carbon oxidation. A/A SBR showed very good N and P removal capacities with excellent sludge settling properties. On the other hand, organic carbon removal efficiency with nitrate was lower than with oxygen. Batch biofilm nitrification was very effective, with very high nitrification rates. Presence of poly-P bacteria in the A/A SBR sludge was assessed through microscopic observation and from the high cellular poly-phosphate content.

Summer-winter transitions in Antarctic ponds II: Biological responses

2011 ◽  
Vol 23 (3) ◽  
pp. 243-254 ◽  
Author(s):  
Ian Hawes ◽  
Karl Safi ◽  
Jenny Webster-Brown ◽  
Brian Sorrell ◽  
David Arscott
Keyword(s):  
Dissolved Oxygen ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Inorganic Nitrogen ◽  
Phosphorus Uptake ◽  
P Uptake ◽  
Molar Ratio ◽  
Nitrogen And Phosphorus ◽  
Freeze Concentration ◽  
Nitrogen And Phosphorus Uptake

AbstractWe observed ice formation and water column attributes in four shallow Antarctic ponds between January and 7 April 2008. During that time ponds went from ice-free to > 80 cm thick ice, near-freshwater to hypersaline, well-lit to near darkness and temperatures fell to below zero. Here we examine shifts in biological activity that accompanied these changes. During February, freeze-concentration and ongoing photosynthesis increased dissolved oxygen concentration to up to 100 mg l-1, with a near-equivalent decrease in dissolved inorganic carbon and a pH rise. Benthic photosynthesis was responsible for 99% of estimated biological oxygen production. Net oxygen accumulation ceased in late February, pH began to fall and inorganic carbon to increase, but the pool of dissolved oxygen was depleted only slowly. Anoxia had been attained in only one pond by April and there was little accumulation of indicators of anaerobic activity. The nitrogen and phosphorus balances of the ponds were dominated by organic forms, which, like DOC and CDOM, behaved conservatively. Conversely, inorganic nitrogen and phosphorus uptake was evident throughout the study period, at a molar ratio of 16N:1P in two of three ponds, consistent with uptake into biological material. We found no coupling between N and P uptake and photosynthesis.

scholarly journals Comment on "Solute-specific scaling of inorganic nitrogen and phosphorus uptake in streams" by Hall et al. (2013)

2015 ◽  
Vol 12 (18) ◽  
pp. 5365-5369 ◽  
Author(s):  
R. González-Pinzón ◽  
J. Mortensen ◽  
D. Van Horn
Keyword(s):  
Nutrient Uptake ◽  
Inorganic Nitrogen ◽  
Phosphorus Uptake ◽  
River Continuum ◽  
Nitrogen And Phosphorus ◽  
Scaling Method ◽  
Nutrient Demand ◽  
Specific Discharge ◽  
Nitrogen And Phosphorus Uptake ◽  
Tracer Experiments

Abstract. Hall et al. (2013) presented a synthesis on 969 nutrient tracer experiments conducted primarily in headwater streams (generally < fourth-order streams), with discharges < 200 L s−1 for ~90 % of the experiments, and used a scaling method to test the hypothesis that nutrient demand is constant with increasing stream size (i.e., along a river continuum). In this comment we present a reanalysis of a subset of the data used by Hall et al. (2013) and propose that their correlations between nutrient uptake lengths of ecologically important solutes and specific discharge are inadvertently spurious. Therefore, the conclusions derived from such correlations are debatable. We conclude the comment by highlighting some of the uncertainties associated with using modeling frameworks for scaling nutrient uptake in stream ecosystems.

scholarly journals LED Lighting and High-Density Planting Enhance the Cost-Efficiency of Halimione portulacoides Extraction Units for Integrated Aquaculture

2021 ◽  
Vol 11 (11) ◽  
pp. 4995
Author(s):  
Marco Custódio ◽  
Paulo Cartaxana ◽  
Sebastián Villasante ◽  
Ricardo Calado ◽  
Ana Isabel Lillebø
Keyword(s):  
Plant Density ◽  
Inorganic Nitrogen ◽  
High Density ◽  
Planting Density ◽  
Nitrogen And Phosphorus ◽  
Integrated Aquaculture ◽  
Halimione Portulacoides ◽  
White Leds ◽  
Artificial Lighting ◽  
Aquaculture Effluents

Halophytes are salt-tolerant plants that can be used to extract dissolved inorganic nutrients from saline aquaculture effluents under a production framework commonly known as Integrated Multi-Trophic Aquaculture (IMTA). Halimione portulacoides (L.) Aellen (common name: sea purslane) is an edible saltmarsh halophyte traditionally consumed by humans living near coastal wetlands and is considered a promising extractive species for IMTA. To better understand its potential for IMTA applications, the present study investigates how artificial lighting and plant density affect its productivity and capacity to extract nitrogen and phosphorous in hydroponic conditions that mimic aquaculture effluents. Plant growth was unaffected by the type of artificial lighting employed—white fluorescent lights vs. blue-white LEDs—but LED systems were more energy-efficient, with a 17% reduction in light energy costs. Considering planting density, high-density units of 220 plants m−2 produced more biomass per unit of area (54.0–56.6 g m−2 day−1) than did low-density units (110 plants m−2; 34.4–37.1 g m−2 day−1) and extracted more dissolved inorganic nitrogen and phosphorus. Overall, H. portulacoides can be easily cultivated hydroponically using nutrient-rich saline effluents, where LEDs can be employed as an alternative to fluorescent lighting and high-density planting can promote higher yields and extraction efficiencies.

scholarly journals Feedback Regulation between Aquatic Microorganisms and the Bloom-Forming Cyanobacterium Microcystis aeruginosa

2019 ◽  
Vol 85 (21) ◽  
Author(s):  
Meng Zhang ◽  
Tao Lu ◽  
Hans W. Paerl ◽  
Yiling Chen ◽  
Zhenyan Zhang ◽  
...  
Keyword(s):  
Energy Metabolism ◽  
Microcystis Aeruginosa ◽  
Lake Taihu ◽  
Inorganic Nitrogen ◽  
Microbial Community Composition ◽  
Nitrogen And Phosphorus ◽  
Content Type ◽  
Coculture System ◽  
Eukaryotic Microorganisms ◽  
Aquatic Microorganisms

ABSTRACT The frequency and intensity of cyanobacterial blooms are increasing worldwide. Interactions between toxic cyanobacteria and aquatic microorganisms need to be critically evaluated to understand microbial drivers and modulators of the blooms. In this study, we applied 16S/18S rRNA gene sequencing and metabolomics analyses to measure the microbial community composition and metabolic responses of the cyanobacterium Microcystis aeruginosa in a coculture system receiving dissolved inorganic nitrogen and phosphorus (DIP) close to representative concentrations in Lake Taihu, China. M. aeruginosa secreted alkaline phosphatase using a DIP source produced by moribund and decaying microorganisms when the P source was insufficient. During this process, M. aeruginosa accumulated several intermediates in energy metabolism pathways to provide energy for sustained high growth rates and increased intracellular sugars to enhance its competitive capacity and ability to defend itself against microbial attack. It also produced a variety of toxic substances, including microcystins, to inhibit metabolite formation via energy metabolism pathways of aquatic microorganisms, leading to a negative effect on bacterial and eukaryotic microbial richness and diversity. Overall, compared with the monoculture system, the growth of M. aeruginosa was accelerated in coculture, while the growth of some cooccurring microorganisms was inhibited, with the diversity and richness of eukaryotic microorganisms being more negatively impacted than those of prokaryotic microorganisms. These findings provide valuable information for clarifying how M. aeruginosa can potentially modulate its associations with other microorganisms, with ramifications for its dominance in aquatic ecosystems. IMPORTANCE We measured the microbial community composition and metabolic responses of Microcystis aeruginosa in a microcosm coculture system receiving dissolved inorganic nitrogen and phosphorus (DIP) close to the average concentrations in Lake Taihu. In the coculture system, DIP is depleted and the growth and production of aquatic microorganisms can be stressed by a lack of DIP availability. M. aeruginosa could accelerate its growth via interactions with specific cooccurring microorganisms and the accumulation of several intermediates in energy metabolism-related pathways. Furthermore, M. aeruginosa can decrease the carbohydrate metabolism of cooccurring aquatic microorganisms and thus disrupt microbial activities in the coculture. This also had a negative effect on bacterial and eukaryotic microbial richness and diversity. Microcystin was capable of decreasing the biomass of total phytoplankton in aquatic microcosms. Overall, compared to the monoculture, the growth of total aquatic microorganisms is inhibited, with the diversity and richness of eukaryotic microorganisms being more negatively impacted than those of prokaryotic microorganisms. The only exception is M. aeruginosa in the coculture system, whose growth was accelerated.

scholarly journals Global Landscape of Total Organic Carbon, Nitrogen and Phosphorus in Lake Water

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Ming Chen ◽  
Guangming Zeng ◽  
Jiachao Zhang ◽  
Piao Xu ◽  
Anwei Chen ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Total Organic Carbon ◽  
Lake Water ◽  
Nitrogen And Phosphorus
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