scholarly journals The Effects of Concentration Gradient of Nitrogen Compounds on the Ammonium-nitrogen and Nitrate-nitrogen Fluxes at Sediment-Water Interface

2021 ◽  
Author(s):  
Han Wang ◽  
Qing Wu ◽  
Yuping Han
Keyword(s):  
Nitrate Nitrogen ◽  
Diffusion Flux ◽  
Ammonium Nitrogen ◽  
Nutrient Concentrations ◽  
Water Interface ◽  
Incubation Experiment ◽  
Concentration Gradients ◽  
Overlying Water ◽  
Average Diffusion ◽  
Nitrogen Concentrations

Abstract The incubation experiments focused on altering concentration gradients of nitrogen between sediment and overlying water to examine the diffusion flux of ammonium-nitrogen (NH4+) and nitrate-nitrogen (NO3-) at sediment-water interface. In this study, the diffusion flux can be estimated based on calculating the average of the net change rate of nutrient concentrations in the overlying water. For the incubation experiment of different TN concentrations in the sediment, the results showed that the diffusion flux of ammonia at sediment-water interface is -52.57~84.57 mg·m-2·d-1, and for nitrate diffusion flux, the changing range during the incubation experiment is -110.13~143.25 mg·m-2·d-1. For the incubation experiment of different nitrogen concentrations in the overlying water, the results of NH4+-N diffusion flux in L, M, H treatment were 3.37, -4.94, -3.84 mg·m-2·d-1, respectively. And the average diffusion flux of nitrate in L (0 mg NO3--N, 0 mg NH4+-N), M (0.5 mg NO3--N, 1.5 mg NH4+-N) and H (1 mg NO3--N, 2.5 mg NH4+-N) treatment were 12.30, 10.39 and 7.11 mg·m-2·d-1. Results highlighted that concentrations gradient of nutrients were indeed an important factor affecting the diffusion flux at sediment-water interface. In addition, the diffusion of nutrients at sediment-water interface in aquatic ecosystem is not only controlled by concentration gradients, some other factors such as incoming water, hydrodynamics, dissolved oxygen content, sediment structure, biological disturbance, horizontal migration and diffusion of nutrients and turbulent diffusion caused by wind and wave, are equally important.

scholarly journals The effect of pulverising aeration on changes in the oxygen and nitrogen concentrations in water of Lake Starzyc

2015 ◽  
Vol 25 (1) ◽  
pp. 31-36 ◽  
Author(s):  
Piotr Wesołowski ◽  
Adam Brysiewicz
Keyword(s):  
Dissolved Oxygen ◽  
Nitrate Nitrogen ◽  
Ecological Status ◽  
Ammonium Nitrogen ◽  
Abiotic Conditions ◽  
The Third ◽  
Long Period ◽  
Nitrogen Concentrations ◽  
Bottom Waters ◽  
Restoration Measures

Abstract Due to poor ecological status of Lake Starzyc, lake restoration measures were undertaken in 2003 to improve aerobic conditions of near-bottom waters and to decrease phosphorus concentrations. To do this, a wind-driven pulverising aerator was installed in the lake. The aim of this study was to analyse variability of oxygen and nitrogen concentrations in lake water near the aerator in the third year of its operation and later on in the three-year-long period of the years 2008–2010. It was found that concentrations of ammonium-nitrogen, nitrate-nitrogen and dissolved oxygen near the aerator did not differ from those in sites 4 and 5, which evidenced similar abiotic conditions in analysed waters. Higher concentrations of dissolved oxygen and lower concentrations of nitrate-nitrogen were found in the years 2008–2010 than in 2005.

scholarly journals Diffusion flux of phosphorus nutrients at the sediment–water interface of the Ulansuhai Lake in northern China

2017 ◽  
Vol 75 (6) ◽  
pp. 1455-1465 ◽  
Author(s):  
Shengnan Zhao ◽  
Xiaohong Shi ◽  
Changyou Li ◽  
Sheng Zhang ◽  
Biao Sun ◽  
...  
Keyword(s):  
Interstitial Water ◽  
Diffusion Flux ◽  
Northern China ◽  
Inorganic Phosphorus ◽  
Exchange Capacity ◽  
Internal Source ◽  
Water Interface ◽  
Overlying Water ◽  
Water And Sediment ◽  
Exchange Flux

Overlying water and sediment samples were collected from 11 locations in Ulansuhai Lake in June of 2012 to determine the concentration of dissolved inorganic phosphorus (DIP) in the interstitial water, overlying water and sediment and to estimate the diffusion flux of DIP at the sediment–water interface. The DIP levels in overlying water were 0.004–0.185 mg/L (average = 0.062 mg/L), while they were 0.05–0.25 mg/L (average = 0.124 mg/L) in the interstitial water in the 0–2 cm surface sediment. Moreover, the annual mean exchange flux of DIP in the sediment was between −0.092 mg/m2·d and 0.053 mg/m2·d, and this occurred via internal source action in most areas. After area weighting, it is estimated that the exchange capacity of DIP at the sediment–water interface of the Ulansuhai Lake is 1.30 t/a. These findings indicate internal loading of phosphorus in sediment of the Ulansuhai Lake; thus, the diffusion of DIP in the interstitial water has effects on the lake, with a degree of influence of 2.7% to 81.5%.

The Influence of Emergent Macrophytes on Porewater PO43- Distribution and Physic Transport in the Estuary Wetlands

2012 ◽  
Vol 610-613 ◽  
pp. 2683-2687
Author(s):  
Xiao Zhi Gu ◽  
Kai Ning Chen ◽  
Wei Huang ◽  
Xiang Bai ◽  
Cheng Xin Fan
Keyword(s):  
Phragmites Australis ◽  
Diffusion Flux ◽  
Typha Latifolia ◽  
Benthic Flux ◽  
Benthic Organism ◽  
Water Interface ◽  
Emergent Macrophytes ◽  
Overlying Water ◽  
Core Sediments ◽  
Incubation Experiments

Emergent macrophytes growth and development are believed to play an important role in nutrients physical transport processes and biogeochemical cycles. In the present study, a high-resolution in-situ sampling technology (Porewater equilibrators, Peepers) was employed to obtain vertical porewater PO43- profiles from the vegetated and the non-vegetated sediments, and accurately quantify benthic flux across sediment-water interface by Fick's first law applying porewater profiles of peepers, and coupled with core sediments incubation experiments as comparison. In addition, to distinguish benthic organism contribution to measured apparent benthic flux, we used HgCl2 (0.5% by weight) to suppress bottom fauna activity during the experiment. The results showed that porewater PO43- concentrations were far lower in vegetated than in the non-vegetated sediments, and also significantly lower in overlying water than in porewater. Whereas, porewater PO43- distribution fluctuated sharply at the upper sediments and kept an approximative constant below 8cm depth. Additionally, the average molecular diffusion flux applying Fick's first law fluctuated slightly within the range of 0.004 to 0.018 mg m-2 d-1(i.e., PO43- from porewater diffused into overlying water), which was higher in typha latifolia site, but lower in zizania latifolia site. PO43- average apparent diffusion flux based on core sediments incubation experiments varied between 1.03 and 6.78 mg m-2 d-1, and an opposite pattern was observed with respect to emergent macrophyte effects, as the PO43- flux at phragmites australis site was low (only 19% of control), but reached as high as 126% of the control in typha latifolia site. In unsterilized treatments (i.e., benthic organism participation), PO43- average net fluxes were lower up to an order of magnitude and more variable compared with those in sterilized treatments. Our results highlighted emergent macrophytes (e.g., phragmites australis) in estuary wetlands could efficiently relieved release risk from sediments, and reduce dissolved reactive phosphorus diffusion physical barrier crossed sediment-water interface by adding porosity in surface sediment.

scholarly journals Tolerance of Tetraselmis tetrathele to High Ammonium Nitrogen and Its Effect on Growth Rate, Carotenoid, and Fatty Acids Productivity

2021 ◽  
Vol 9 ◽  
Author(s):  
Abd Wahab Farahin ◽  
Ikhsan Natrah ◽  
Norio Nagao ◽  
Fatimah Md. Yusoff ◽  
Mohamed Shariff ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Growth Rate ◽  
Photosynthetic Efficiency ◽  
Nitrate Nitrogen ◽  
Ammonium Nitrogen ◽  
High Concentration ◽  
Nitrogen Concentrations ◽  
High Level ◽  
Microalgae Productivity ◽  
Β Carotene

Microalgae can use either ammonium or nitrate for its growth and vitality. However, at a certain level of concentration, ammonium nitrogen exhibits toxicity which consequently can inhibit microalgae productivity. Therefore, this study is aimed to investigate the tolerance of Tetraselmis tetrathele to high ammonium nitrogen concentrations and its effects on growth rate, photosynthetic efficiency (Fv/Fm), pigment contents (chlorophyll a, lutein, neoxanthin, and β-carotene), and fatty acids production. Experiments were performed at different ammonium nitrogen concentrations (0.31–0.87 gL−1) for 6 days under a light source with an intensity of 300 μmol photons m−2 s−1 and nitrate-nitrogen source as the experimental control. The findings indicated no apparent enhancement of photosynthetic efficiency (Fv/Fm) at high levels of ammonium nitrogen (NH4+-N) for T. tetrathele within 24 h. However, after 24 h, the photosynthetic efficiency of T. tetrathele increased significantly (p < 0.05) in high concentration of NH4+-N. Chlorophyll a content in T. tetrathele grown in all of the different NH4+-N levels increased significantly compared to nitrate-nitrogen (NO3-N) treatment (p < 0.05); which supported that this microalgal could grow even in high level of NH4+-N concentrations. The findings also indicated that T. tetrathele is highly resistant to high ammonium nitrogen which suggests T. tetrathele to be used in the aquaculture industry for bioremediation purpose to remove ammonium nitrogen, thus reducing the production cost while improving the water quality.

scholarly journals Determination of Water Quality Characteristics and Nutrient Exchange Flux at the Sediment–Water Interface of the Yitong River in Changchun City, China

Water ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 3555
Author(s):  
Ke Zhao ◽  
Hang Fu ◽  
Qian Wang ◽  
Hai Lu
Keyword(s):  
Water Quality ◽  
Interstitial Water ◽  
Diffusion Flux ◽  
Pollution Index ◽  
Ammonia Nitrogen ◽  
Water Interface ◽  
Nitrogen And Phosphorus ◽  
Overlying Water ◽  
Nitrogen Pollutants ◽  
Exchange Flux

In this paper, the characteristics of water pollution in Yitong River were analyzed by the comprehensive pollution index method. Combined with the pore water concentration gradient method and Fick’s first law, the release characteristics of nutrients at the sediment–water interface of Yitong River (Jilin Province, China) were studied. The results showed that the distribution trend of nitrogen and phosphorus content in the overlying and interstitial water of the Yitong River was the same, and the highest values appeared at the S3 and S5 points in the urban section. The water quality was mainly affected by nitrogen pollutants in domestic sewage. The evaluation results of the water quality comprehensive pollution index showed that the pollution degree of interstitial water in urban areas was much higher than that of the overlying water, and the endogenous nitrogen and phosphorus pollutants had the risk of diffusion to the overlying water. The exchange flux analysis of ammonia nitrogen (NH4+-N), total dissolved nitrogen (TDN), and total dissolved phosphorus (TDP) in water showed that the diffusion flux of NH4+-N ranged from 0.03 to 6.52 mg·(m2·d)−1, and the sediment was the “source” of ammonia nitrogen pollutants. The range of TDN diffusion flux was −1.57 to 11.6 mg·(m2·d) −1, and the difference between points was large. The sediment was both the “source” and “sink” of nitrogen pollutants. The range of TDP diffusion flux was −0.05 to 0.22 mg·(m2·d) −1. Except for point S8, the TDP diffused from sediment into the water body. Among all the sampling points, the diffusion fluxes of NH4+-N, TDN, and TDP at the S3 point were the largest, the release rate of endogenous pollutants was the most rapid, and the pollution to the water quality was the most serious. The results are of great significance to the exchange flux of nutrients at the sediment–water interface of rivers and the prevention and control of water eutrophication. It also provides a reference for the study of nutrient exchange flux at the sediment–water interface of rivers and other surface water bodies worldwide.

scholarly journals Effect of Different Proportions of Three Microbial Agents on Ammonia Mitigation during the Composting of Layer Manure

Molecules ◽  
2019 ◽  
Vol 24 (13) ◽  
pp. 2513 ◽  
Author(s):  
Zhou ◽  
Zhang ◽  
Liao ◽  
Wu ◽  
Mi ◽  
...  
Keyword(s):  
Bacillus Stearothermophilus ◽  
Nitrate Nitrogen ◽  
Ammonium Nitrogen ◽  
Control Group ◽  
Bacterial Number ◽  
Ammonia Oxidizing Bacteria ◽  
Ammonia Emissions ◽  
Total Ammonia ◽  
Nitrogen Concentrations ◽  
Microbial Agents

Odor emissions represent one of the important issues of aerobic composting. The addition of microbial agents to compost is an important method for solving this problem, but this process is often unstable when a single microbial agent is added to the compost. Therefore, in this study, five treatments comprising different proportions of Bacillus stearothermophilus, Candida utilis, and Bacillus subtilis were tested to determine the best combination of the three microbial agents for ammonia reduction, as follows: control group (CK), 2:1:1 (A), 1:1:2 (B), 1:2:1 (C), and 1:1:1 (D). Compared with the CK group, the A, B, C, and D groups reduced ammonia emissions by 17.02, 9.68, 53.11, and 46.23%, respectively. The total ammonia emissions were significantly lower in C and D than in CK (p < 0.05). These two treatment groups had significantly increased nitrate nitrogen concentrations and decreased pH values and ammonium nitrogen concentrations (p < 0.05). Throughout the composting process, the total bacterial number was significantly higher in C and D than in CK (p < 0.05). Therefore, it is likely that B. stearothermophilus, C. utilis, and B. subtilis compounded from 1:2:1 (C) to 1:1:1 (D) reduced the ammonia emissions due to (1) a reduction in the pH and (2) the promotion of the growth of ammonia-oxidizing bacteria and the conversion of ammonium nitrogen to nitrate nitrogen. This study provides a theoretical basis and technical support for the odor problem of layer manure compost and promotes the development of composting technology.

Nitrogen cycling in a Venezuelan tropical seasonally flooded forest: soil nitrogen mineralization and nitrification

1994 ◽  
Vol 10 (3) ◽  
pp. 399-416 ◽  
Author(s):  
Barrios E. ◽  
Herrera R.
Keyword(s):  
Soil Nitrogen ◽  
Nitrogen Availability ◽  
Inorganic Nitrogen ◽  
Nitrogen Concentration ◽  
Ammonium Nitrogen ◽  
Wet Season ◽  
Flooded Forest ◽  
Nitrogen Concentrations ◽  
Minimum Stress ◽  
Seasonally Flooded

ABSTRACTSeasonally flooded forests represent a transition between terrestrial and aquatic ecosystems. The Mapire river, a tributary of the Orinoco river, floods its surrounding forests during the wet season (May–December). The soils are very acid and the total nitrogen concentration (0.1%) is only half that found in nearby soils flooded by Orinoco waters. Ammonium-nitrogen predominates in the soil during the flooded period while nitrate-nitrogen concentrations are higher in the dry period. Wide fluctuations in the inorganic nitrogen fractions did not considerably affect the annual course of soil nitrogen.The predominance of mineralization versus nitrification (56 and 5 μgsoil month−1respectively) and possibly the synchronization of nitrogen availability with plant demand could be considered as nitrogen conserving mechanisms.In synchrony with the hydrologic cycle, the seasonally flooded forest studied shows a nitrogencycle where inputs and accumulation are maximized when the system is under minimum stress (dry season). During flooding, the system enters a period of dormancy making minimal use of nutrient and energy to avoid or tolerate anaerobiosis.

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