scholarly journals On the Ratio of Nitrogen to Phosphorus in the Sea

1937 ◽  
Vol 22 (1) ◽  
pp. 177-182 ◽  
Author(s):  
L. H. N. Cooper
Keyword(s):  
Nitrate Nitrogen ◽  
Marine Plankton ◽  
Nitrogen And Phosphorus ◽  
Broad Outline ◽  
Broad Generalization

Data are presented confirming the belief of Harvey and of Redfield that, in broad outline, the ratio of nitrate-nitrogen and of phosphate-phosphorus in the sea and of nitrogen and phosphorus in marine plankton lies within fairly narrow limits. The ratio approaches twenty to one when expressed in terms of milligram-atoms or nine to one by weight. There are however deviations from this broad generalization, but they do not provide a reason for discarding the concept but rather suggest close examination of the causes of the variations.

Mechanism Analysis and Experimental Research on the Interception of Nitrogen and Phosphorus Pollutants by Gullies in Northern China

2011 ◽  
Vol 250-253 ◽  
pp. 3392-3396
Author(s):  
Yu Jia Song ◽  
Hui Qing Liu
Keyword(s):  
Total Phosphorus ◽  
Nitrate Nitrogen ◽  
Northern China ◽  
Careful Analysis ◽  
Ammonia Nitrogen ◽  
Mechanism Analysis ◽  
Nitrogen And Phosphorus ◽  
Urban Sewage ◽  
Control Section ◽  
Nitrogen Pollutants

The discharge of urban sewage and agricultural non-point source pollutants is the main reason causing eutrophication in gullies in most cities of northern China. Based on a careful analysis on the ecological structure and ecological characteristics of a gully, this article preliminarily studies the interception and degradation mechanisms of nitrogen pollutants by the gully. Meanwhile, to take gullies in Changchun as the object of the study, this article carries out an experiment on the interception effect of nitrogen pollutants by gullies. This experiment respectively establishes a control section in the upper and lower reaches of a gully, and takes water samples four times in each section from May to August to determine total nitrogen, total phosphorus, nitrate nitrogen, ammonia nitrogen and salinity. The result shows: the gully plays some role in the interception of pollutants; total phosphorus accounts for the largest interception in pollutants in the experimented gully section, with the relative interception rate of 27.46%, followed by ammonia nitrogen, with the interception rate of 21.80%, which is the result of the combined effects of aquatic plants, microorganisms and sediment in the gully.

scholarly journals (48) Substrate Media and Fertilizer Source Affect Nitrogen and Phosphorus Levels in Leachate from Container-grown Shasta Daisy

HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 1055B-1055
Author(s):  
Gladis Zinati
Keyword(s):  
Nitrate Nitrogen ◽  
Nitrogen Concentration ◽  
Dry Weight ◽  
Pine Bark ◽  
Nitrogen Release ◽  
Irrigation Regime ◽  
Nitrogen And Phosphorus ◽  
Recommended Level ◽  
Phosphorus Levels

Plugs of Leucanthemum × superbum `Becky' (Chrysanthemum `Becky', shasta daisy) were grown in #2 containers using pine bark–peat–sand or vermiculite–peat–sand (40:40:20 by volume). Containers were top dressed with either Osmocote Plus 15N–3.9P–9.9K (15–9–12) or Nutricote Plus (18N–2.6P–6.6K (18–6–8) at five rates (0, 0.5×, 1.0×, 1.5×, and 2.0×) to supply 3.9 g N per container at the recommended level (1.0×). Plants were irrigated twice a week using a cyclic irrigation regime consisting of two irrigation applications. Leachates from these containers were collected and evaluated for nitrate and orthophosphate concentrations. Irrespective of the substrate media, Osmocote Plus exhibited a higher rate of nitrogen release at the beginning of the season than Nutricote Plus. Nitrate nitrogen concentration was at least 2.5 times higher in leachates collected from media amended with Osmocote Plus than those with Nutricote Plus. Higher levels of nitrate were found in leachates collected from vermiculite-based media when compared to those from bark-based ones. Phosphate levels in leachates increased as rate of fertilizer increased and were higher in vermiculite-based media than those collected from bark-based media. Plants fertilized with Osmocote Plus were 1.7-fold greater in dry weight than plants fertilized with Nutricote Plus and were 1.2 times greater in vermiculite-based media than those in bark-based media.

Skeleton weed (Chondrilla juncea) in the Victorian Mallee. 4. Effects of fallowing on wheat yields and weed populations

1971 ◽  
Vol 11 (50) ◽  
pp. 313 ◽  
Author(s):  
GJ Wells
Keyword(s):  
Soil Nitrogen ◽  
Nitrate Nitrogen ◽  
Wheat Yield ◽  
Individual Response ◽  
Phosphorus Fertilizer ◽  
Nitrogen And Phosphorus ◽  
Rainfall Distribution ◽  
Weed Density ◽  
Weed Growth ◽  
The Individual

Experiments to compare the duration of fallows and the substitution of a 2,4-D spray for some fallow cultivations for wheat production on skeleton weed land were conducted in the Victorian Mallee from 1962 to 1966. Generally winter fallows outyielded spring fallows, commenced only two months later, and these in turn gave higher yields than an autumn-cultivated treatment. Compared with autumn cultivation, winter fallowing reduced skeleton weed density by an average of 49 per cent. Substituting a 2,4-D spray for some Gltivations had little effect on wheat yield, but improved the control of skeleton weed. Grain yield was determined primarily by the level of nitrate nitrogen in the surface 15 cm of soil before sowing, and this effect was attributed to the low soil nitrogen status found in skeleton weed situations. Soil moisture was conserved only occasionally, owing to the difficulty of controlling weed growth during the summer coupled with the variable rainfall distribution in the Mallee. Although a nitrogen and phosphorus fertilizer interaction was significant at all sites, neither the individual response nor the interaction was affected by fallow treatment.

scholarly journals Incorporating Rainfall-Runoff Events into Nitrate-Nitrogen and Phosphorus Load Assessments for Small Tile-Drained Catchments

Water ◽  
2017 ◽  
Vol 9 (9) ◽  
pp. 712 ◽  
Author(s):  
Petr Fučík ◽  
Antonín Zajíček ◽  
Markéta Kaplická ◽  
Renata Duffková ◽  
Jana Peterková ◽  
...  
Keyword(s):  
Nitrate Nitrogen ◽  
Rainfall Runoff ◽  
Phosphorus Load ◽  
Nitrogen And Phosphorus ◽  
Nitrogen And Phosphorus Load ◽  
Runoff Events

Groundwater loading of nitrate-nitrogen and phosphorus from watershed source areas to an Iowa Great Lake

2016 ◽  
Vol 42 (3) ◽  
pp. 588-598 ◽  
Author(s):  
Keith E. Schilling ◽  
Matthew T. Streeter ◽  
Deborah Quade ◽  
Mary Skopec
Keyword(s):  
Great Lake ◽  
Nitrate Nitrogen ◽  
Nitrogen And Phosphorus ◽  
Source Areas

scholarly journals Spatiotemporal distribution of nitrogen and phosphorus in alpine lakes in the Sanjiangyuan Region of the Tibetan Plateau

2017 ◽  
Vol 76 (2) ◽  
pp. 396-412 ◽  
Author(s):  
Su-jin Lu ◽  
Jian-huan Si ◽  
Chuan-ying Hou ◽  
Yu-si Li ◽  
Meng-meng Wang ◽  
...  
Keyword(s):  
Total Nitrogen ◽  
Total Phosphorus ◽  
Nitrate Nitrogen ◽  
Quality Standards ◽  
Alpine Lakes ◽  
Ammonia Nitrogen ◽  
Sea Star ◽  
Water Quality Standards ◽  
Nitrogen And Phosphorus ◽  
Nitrite Nitrogen

To provide a theoretical basis for alpine source lake protection, ten samples were taken from each lake annually from 2012 to 2015. Each year, the various species of nitrogen and phosphorus nutrients were measured. The average contents of nitrate nitrogen, ammonia nitrogen, nitrite nitrogen, total phosphorus, and total nitrogen in the four lakes are 0.195–0.0 mg/L, 0.038–0.143 mg/L, 0.004–0.168 mg/L, 0.006–0.740 mg/L, and 0.050–0.547 mg/L, respectively. The total phosphorus contents in Eling Lake, Longbao Lake and Sea Star were higher than Class I water quality standards, and the total nitrogen contents in Eling Lake, Sea Star and Zhaling Lake were higher than Class I water quality standards as well. The concentration contour maps of the nitrate nitrogen, ammonia nitrogen, nitrite nitrogen, total phosphorus and total nitrogen showed that the indicators of the four lakes in the east, the west, and the center of the lake did not have the same trend. From 2012 to 2015, each of the measured nutrients showed a rising trend year by year. The four lakes are polluted by both endogenous and exogenous pollution, and it is necessary to limit the exogenous pollution and protect the alpine lakes immediately.

Removal of nitrogen and phosphorus from the secondary effluent in tertiary denitrifying biofilters combined with micro-coagulation

2016 ◽  
Vol 73 (11) ◽  
pp. 2754-2760 ◽  
Author(s):  
Nan Wei ◽  
Yunhong Shi ◽  
Guangxue Wu ◽  
Hongying Hu ◽  
Yumei Guo ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Nitrate Nitrogen ◽  
The Other ◽  
Effective Control ◽  
Secondary Effluent ◽  
Simultaneous Removal ◽  
Nitrogen And Phosphorus ◽  
N Removal ◽  
Quartz Sands ◽  
Receiving Water

Effective control of nitrogen and phosphorus in secondary effluent can reduce or avoid the eutrophication of receiving water bodies. Two denitrifying biofilters (DNBFs) packed with different sizes of quartz sands combined with micro-coagulation were operated for simultaneous removal of nitrogen and phosphorus from the secondary effluent. The quartz sand size in one DNBF was 2–4 mm (DNBFS), and in the other was 4–6 mm (DNBFL). In both DNBFs, methanol was used as the electron donor and different organic carbon to nitrogen (C/N) ratios were applied. Under C/N ratios of 1.5, 1.25, and 0.75 g/g, the nitrate nitrogen (NO3−-N) removal percentages were 73%, 77%, and 50% in DNBFS, and 43%, 25%, and 21% in DNBFL; the effluent total phosphorus concentrations were 0.15, 0.14, and 0.18 mg/L in DNBFS, and 0.29, 0.35, and 0.24 mg/L in DNBFL. The performance of both biofilters was quite stable within a backwashing cycle. The NO3−-N reduction rates were 1.31, 1.10, and 0.48 mg/(L·min) in DNBFS, and 0.97, 0.27, and 0.10 mg/(L·min) in DNBFL. For biomass detached from both biofilters, their denitrifying activities were similar. Biofilm biomass in DNBFS was higher than that in DNBFL, inducing a high denitrification efficiency in DNBFS.

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