scholarly journals Phosphorus: a rate limiting nutrient in surface waters

1999 ◽  
Vol 78 (5) ◽  
pp. 674-682 ◽  
Author(s):  
DL Correll
Keyword(s):  
Surface Waters ◽  
Limiting Nutrient ◽  
Rate Limiting

scholarly journals Edge-of-Field Technologies for Phosphorus Retention from Agricultural Drainage Discharge

2020 ◽  
Vol 10 (2) ◽  
pp. 634 ◽  
Author(s):  
Lipe Renato Dantas Mendes
Keyword(s):  
Surface Waters ◽  
Organic Phosphorus ◽  
Freshwater Ecosystems ◽  
Phosphorus Retention ◽  
Buffer Strips ◽  
Large Variability ◽  
Agricultural Catchments ◽  
Limiting Nutrient ◽  
Phosphorus Form ◽  
Subsurface Drains

Agriculture is often responsible for the eutrophication of surface waters due to the loss of phosphorus—a normally limiting nutrient in freshwater ecosystems. Tile-drained agricultural catchments tend to increase this problem by accelerating the transport of phosphorus through subsurface drains both in dissolved (reactive and organic phosphorus) and particulate (particle-bound phosphorus) forms. The reduction of excess phosphorus loads from agricultural catchments prior to reaching downstream surface waters is therefore necessary. Edge-of-field technologies have been investigated, developed and implemented in areas with excess phosphorus losses to receive and treat the drainage discharge, when measures at the farm-scale are not able to sufficiently reduce the loads. The implementation of these technologies shall base on the phosphorus dynamics of specific catchments (e.g., phosphorus load and dominant phosphorus form) in order to ensure that local retention goals are met. Widely accepted technologies include constructed wetlands, restored wetlands, vegetated buffer strips and filter materials. These have demonstrated a large variability in the retention of phosphorus, and results from the literature can help targeting specific catchment conditions with suitable technologies. This review provides a comprehensive analysis of the currently used edge-of-field technologies for phosphorus retention in tile-drained catchments, with great focus on performance, application and limitations.

Quality characteristics of surface and sea waters in Greece in relation to European union legislation

1995 ◽  
Vol 32 (7) ◽  
pp. 183-190 ◽  
Author(s):  
A. D. Andreadakis ◽  
A. Katsara
Keyword(s):  
European Union ◽  
Surface Waters ◽  
Agricultural Practices ◽  
Quality Characteristics ◽  
Public Works ◽  
Water Bodies ◽  
Treated Sewage ◽  
Limiting Nutrient ◽  
Agriculture And Environment ◽  
European Union Legislation

The paper summarises the results of a survey of the quality characteristics of 21 lakes, 24 rivers and 5 gulfs in Greece. The field data was collected by the Ministries of Agriculture and Environment & Public Works and covers the period 1989–1992. Data processing and evaluation, in order to determine the degree of pollution and the sensitivity of the water bodies, was conducted by considering the relevant European Union (EU) legislation. The quality characteristics of 90% of the surface waters do not violate the mandatory limits of the Directives 75/440 and 80/440. However, a significant number of lakes (about 60%) are meso-eutrophic or eutrophic with nitrogen being the limiting nutrient. The main sources of nitrogen in these cases are related to agricultural practices and the measures specified in Directive 91/676 (closer monitoring, improvement of agricultural practices) should be implemented. Furthermore, the discharge of treated sewage should be avoided or in any case the degree of treatment should include nutrients removal, in accordance with the requirements of the Directive 91/271 for sensitive recipients. The evaluation of the quality characteristics of the examined gulfs was performed taking into consideration the classification proposed by the Directive 91/271, which is based on the degree of sensitivity of the water bodies with respect to eutrophication.

Seasonal Variation of Potential Nutrient Limitation to Chlorophyll Production in Southern Lake Huron

1981 ◽  
Vol 38 (1) ◽  
pp. 1-9 ◽  
Author(s):  
C. Kwei Lin ◽  
Claire L. Schelske
Keyword(s):  
Trace Metals ◽  
Nutrient Limitation ◽  
Surface Waters ◽  
Lake Huron ◽  
Nutrient Additions ◽  
Limiting Nutrients ◽  
Complete Treatment ◽  
Limiting Nutrient ◽  
Chlorophyll Production ◽  
Experimental Treatments

Potential nutrient limitation to chlorophyll production in surface waters of southern Lake Huron was assayed monthly from April to December 1975. Natural phytoplankton assemblage responses to nutrient enrichment were determined from chlorophyll production in laboratory incubations under seasonally varied light and temperature conditions. Experimental treatments included a complete treatment containing P, N, Si, EDTA, vitamins, and trace metals; treatments with deletions from the complete treatment; complete treatments with different P concentrations; and treatments with single nutrient additions. Effects were most pronounced during summer and fall when P, EDTA, FeEDTA, vitamins, and Si were added simultaneously. The intensity of the effect resulting from additions of phosphorus and other nutrients varied seasonally. Individual additions of EDTA, N, and Si had little effect as did deletion of N from the complete treatment. Addition of P alone resulted in limited growth. Deletion of phosphorus from the complete enrichment, however, reduced growth drastically during most experimental periods. In the complete treatment the minimum levels of P that caused significant chlorophyll production ranged from 1 to 3 μg L−1. Chelate (EDTA), chelated iron, and vitamins were important secondary limiting nutrients during the summer months. There was a small effect due to silica in July, September, and October, and no indication of deficiency in trace metals. Trace metals, when deleted, frequently produced greater chlorophyll than the complete treatment, but growth was sharply reduced by deletion of trace metals and EDTA combined. The results clearly demonstrate that large increases in chlorophyll production in southern Lake Huron require simultaneous additions of the primary limiting nutrient (P) and secondary limiting nutrients (EDTA, FeEDTA, and vitamins) which vary seasonally.Key words: chlorophyll, eutrophication, micronutrients, phosphorus, phytoplankton

scholarly journals N-limited or N and P co-limited indications in the surface waters of three Mediterranean basins

2010 ◽  
Vol 7 (6) ◽  
pp. 8143-8176 ◽  
Author(s):  
T. Tanaka ◽  
T. F. Thingstad ◽  
U. Christaki ◽  
J. Colombet ◽  
V. Cornet-Barthaux ◽  
...  
Keyword(s):  
Surface Waters ◽  
Ammonium Phosphate ◽  
Turnover Time ◽  
General Notion ◽  
Biological Parameters ◽  
Western Basin ◽  
P Limitation ◽  
Levantine Basin ◽  
Limiting Nutrient ◽  
Set Up

Abstract. The limiting nutrient for the pelagic microbial food web in the Mediterranean Sea was investigated in the nutrient manipulated microcosms during summer 2008. Surface waters were collected into 12 carboys at a center of anticyclonic eddy at the Western Basin, the Ionian Basin, and the Levantine Basin, respectively. As compared to the Redfield ratio, the ratio of N to P in the collected waters was always smaller in the dissolved inorganic fraction but higher in both dissolved and particulate organic fractions. Four different treatments in triplicates (addition of ammonium, phosphate, a combination of both, and the unamended control) were set up for the carboys. Responses of chemical and biological parameters in these different treatments were measured during the incubation (3–4 days). Temporal changes of turnover time of phosphate and ATP, and alkaline phosphatase activity during the incubation suggested that the phytoplankton and heterotrophic prokaryotes (Hprok) communities were not purely P-limited at any studied stations. Statistical comparison between the treatments for a given parameter measured at the end of the incubation did not find pure P-limitation in any chemical and biological parameters at three study sites. Primary production was consistently limited by N, and Hprok growth was not limited by N nor P in the Western Basin, but N-limited in the Ionian Basin, and N and P co-limited in the Levantine Basin. Our results demonstrated the gap between biogeochemical features and biological responses in terms of the limiting nutrient. We question the general notion that Mediterranean surface waters are limited by P alone during the stratified period.

Habitat Association of Klebsiella Species

1985 ◽  
Vol 6 (2) ◽  
pp. 52-58 ◽  
Author(s):  
Susan T. Bagley
Keyword(s):  
Drinking Water ◽  
Gastrointestinal Tract ◽  
Surface Waters ◽  
Industrial Effluents ◽  
Opportunistic Pathogen ◽  
Habitat Associations ◽  
Habitat Association ◽  
Klebsiella Species ◽  
Almost All ◽  
Polluted Waters

AbstractThe genus Klebsiella is seemingly ubiquitous in terms of its habitat associations. Klebsiella is a common opportunistic pathogen for humans and other animals, as well as being resident or transient flora (particularly in the gastrointestinal tract). Other habitats include sewage, drinking water, soils, surface waters, industrial effluents, and vegetation. Until recently, almost all these Klebsiella have been identified as one species, ie, K. pneumoniae. However, phenotypic and genotypic studies have shown that “K. pneumoniae” actually consists of at least four species, all with distinct characteristics and habitats. General habitat associations of Klebsiella species are as follows: K. pneumoniae—humans, animals, sewage, and polluted waters and soils; K. oxytoca—frequent association with most habitats; K. terrigena— unpolluted surface waters and soils, drinking water, and vegetation; K. planticola—sewage, polluted surface waters, soils, and vegetation; and K. ozaenae/K. rhinoscleromatis—infrequently detected (primarily with humans).

Identifying Sources of Sulfate Aerosols Reaching Whiteface Mountain, NY

1985 ◽  
Vol 43 ◽  
pp. 98-101
Author(s):  
James S. Webber
Keyword(s):  
Trace Metals ◽  
Acid Deposition ◽  
Surface Waters ◽  
Dry Deposition ◽  
Coal Combustion ◽  
Public Awareness ◽  
Sulfate Aerosols ◽  
Wet And Dry Deposition ◽  
Whiteface Mountain ◽  
Toxic Trace Metals

INTRODUCTION“Acid rain” and “acid deposition” are terms no longer confined to the lexicon of atmospheric scientists and 1imnologists. Public awareness of and concern over this phenomenon, particularly as it affects acid-sensitive regions of North America, have increased dramatically in the last five years. Temperate ecosystems are suffering from decreased pH caused by acid deposition. Human health may be directly affected by respirable sulfates and by the increased solubility of toxic trace metals in acidified waters. Even man's monuments are deteriorating as airborne acids etch metal and stone features.Sulfates account for about two thirds of airborne acids with wet and dry deposition contributing equally to acids reaching surface waters or ground. The industrial Midwest is widely assumed to be the source of most sulfates reaching the acid-sensitive Northeast since S02 emitted as a byproduct of coal combustion in the Midwest dwarfs S02 emitted from all sources in the Northeast.

Ornithine Decarboxylase Activity in Cultured Endothelial Cells Stimulated by Serum, Thrombin and Serotonin

1978 ◽  
Vol 39 (02) ◽  
pp. 496-503 ◽  
Author(s):  
P A D’Amore ◽  
H B Hechtman ◽  
D Shepro
Keyword(s):  
Endothelial Cells ◽  
Ornithine Decarboxylase ◽  
Decarboxylase Activity ◽  
Aortic Endothelial Cells ◽  
Ornithine Decarboxylase Activity ◽  
Rate Limiting Step ◽  
Bovine Aortic Endothelial Cells ◽  
Limiting Step ◽  
Rate Limiting ◽  
Serum Serotonin

SummaryOrnithine decarboxylase (ODC) activity, the rate-limiting step in the synthesis of polyamines, can be demonstrated in cultured, bovine, aortic endothelial cells (EC). Serum, serotonin and thrombin produce a rise in ODC activity. The serotonin-induced ODC activity is significantly blocked by imipramine (10-5 M) or Lilly 11 0140 (10-6M). Preincubation of EC with these blockers together almost completely depresses the 5-HT-stimulated ODC activity. These observations suggest a manner by which platelets may maintain EC structural and metabolic soundness.

Differences in the Interactions of Lupus Anticoagulant IgG with Human Prothrombin and Bovine Prothrombin

1995 ◽  
Vol 73 (04) ◽  
pp. 668-674 ◽  
Author(s):  
L Vijaya Mohan Rao ◽  
An D Hoang ◽  
Samuel I Rapaport
Keyword(s):  
Western Blot ◽  
Lupus Anticoagulant ◽  
Protein A ◽  
Phospholipid Complex ◽  
Experimental Conditions ◽  
Bovine Plasma ◽  
Activation System ◽  
Rate Limiting ◽  
Substantial Extent ◽  
Prothrombin Activation

SummaryLupus anticoagulant (LA) IgGs have been reported to inhibit more effectively and consistently the Xa/Va/phospholipid complex-catalyzed activation of human prothrombin than the Xa/Va/phospholipid complex-catalyzed activation of bovine prothrombin. This led us to carry out studies to determine whether the ability to inhibit the activation of prothrombin of LA IgGs, separated from the plasma of 15 patients by protein A affinity chromatography, could be related to the ability of the LA IgGs to bind to prothrombin under various experimental conditions. Of 14 LA IgG preparations tested all prolonged to a variable but substantial extent the dilute Russell’s viper venom time (dRVVT) of human plasma but only minimally prolonged the dRVVT of bovine plasma. In a purified prothrombin activation system with a rate limiting concentration of phospholipid, all 15 LA IgG preparations inhibited the activation of human prothrombin with the majority showing >50% of inhibition. In contrast, only one LA IgG markedly inhibited (>50%) the activation of bovine prothrombin and five others moderately inhibited (25-40%) the activation of bovine prothrombin. Nevertheless, the majority of LA IgG preparations bound to immobilized bovine prothrombin on a Western blot and also to immobilized bovine prothrombin on a microtiter well. In an ELISA in which phosphatidylserine (PS) was immobilized on microtiter wells, bovine prothrombin supported the binding of 10 of 15 LA IgG preparations to PS. However, the extent of binding was lower than that observed with human prothrombin. In experiments with 125I-human prothrombin or 125I-bovine prothrombin in a solution containing Ca2+, the addition of PS/PC vesicles enhanced the binding of both human and bovine prothrombin to some LA IgG preparations. The enhanced binding was particularly evident for bovine prothrombin. Although seemingly related for some preparations, the ability of a LA IgG to bind to bovine prothrombin, either in the presence or absence of PS, and the ability of that LA IgG to inhibit the activation of bovine prothrombin was not consistently related for all preparations.

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