Improvements in Quantifying the Phosphorus Concentration in Lake Water

1982 ◽  
Vol 39 (6) ◽  
pp. 822-829 ◽  
Author(s):  
E. E. Prepas ◽  
F. H. Rigler
Keyword(s):  
Particulate Matter ◽  
Water Column ◽  
Total Phosphorus ◽  
Lake Water ◽  
Separate Experiment ◽  
Phosphorus Concentration ◽  
Water Bottle ◽  
Acid Digestion ◽  
Average Variance ◽  
The Mean

Vertical and horizontal patterns in limnetic phosphorus concentrations ([P]) were detected in an oligotrophic lake by dividing the total phosphorus pool into two fractions: dissolved and particulate matter smaller than 250 μm (smaller fraction) and particulate matter larger than 250 μm (larger fraction). The smaller fraction was estimated from samples collected with a water bottle, and the larger fraction was estimated with tow net samples taken at several stations and to various depths. Our samples were digested with potassium persulfate which gave less variable results than other acid digestion techniques. The average variance associated with the mean [P] (n = 3) for samples collected and analyzed according to our procedure was less than 0.05 mg P/m3. During summer stratification there was a consistent metalimnetic maximum in the smaller fraction, and there were small but significant differences in the concentrations found at two stations less than 1 km apart. During the same period the larger fraction was a significant portion (14–28%) of the phosphorus pool in the epilimnion which varied from 3 to 5 m in depth. It was a relatively constant portion of the phosphorus in the trophogenic zone (0–10 m) and in the 0- to 20-m portion of the water column i.e. 10–14% and 7.3–8.8%, respectively. In a separate experiment it was shown that by removing the larger fraction, the average variance associated with the mean [P] was reduced from 1.0, to 2.4 × 10−2 mg/m3. This reduction occurred because the larger fraction contained zooplankters with relatively high but variable amounts of phosphorus, and which occur in densities too low to be adequately sampled with the smaller fraction.Key words: phorphorus, lakes, phosphorus in zooplankton

Applicability of Phosphorus Budget Models to Small Precambrian Lakes, Algonquin Park, Ontario

1978 ◽  
Vol 35 (3) ◽  
pp. 300-304 ◽  
Author(s):  
W. A. Scheider
Keyword(s):  
Key Words ◽  
Predictive Model ◽  
Chlorophyll A ◽  
Total Phosphorus ◽  
Lake Water ◽  
Phosphorus Concentration ◽  
Small Lakes ◽  
Total Phosphorus Concentration ◽  
Phosphorus Budget ◽  
The Mean

Phosphorus and hydrological budgets were constructed for four small lakes with Precambrian drainage in Algonquin Park, Ontario. Lake outflow discharge ranged from 21.7 × 105 to 177 × 105 m3∙yr−1. Annual phosphorus input to the lakes from terrestrial drainage and precipitation totaled 36.3–188 kg∙yr−1. The lakes retained 16–41% of the annual input. These data were used to test a series of models that predict the spring total phosphorus concentration in lake water and the mean summer chlorophyll a. The predicted spring phosphorus concentration agreed well with measured values (within 1.3 mg∙m−3) except where human-associated phosphorus input may have contributed to the phosphorus budget of the lake. Agreement between predicted and measured chlorophyll a was not as close. A figure of 0.48 kg P∙capita−1∙yr−1 was calculated as the human-associated supply. Key words: phosphorus budget, chlorophyll a, predictive model, Precambrian lake

Improved Estimation of the Dry Weight of Holopedium gibberum (Crustacea, Cladocera) Using Clutch Size, a Body Fat Index, and Lake Water Total Phosphorus Concentration

1987 ◽  
Vol 44 (2) ◽  
pp. 382-389 ◽  
Author(s):  
N. D. Yan ◽  
G. L. Mackie
Keyword(s):  
Clutch Size ◽  
Body Fat ◽  
Total Phosphorus ◽  
Lake Water ◽  
Dry Weight ◽  
Crustacean Zooplankton ◽  
Phosphorus Concentration ◽  
Total Phosphorus Concentration ◽  
Important Species ◽  
Shield Lakes

Holopedium gibberum is one of the most important species of crustacean zooplankton in Canadian Shield lakes, yet satisfactory length–weight relationships (LWR's) have not been constructed from North American populations. In this report we show that, despite assertions to the contrary, weights of individual H. gibberum can be successfully predicted from body length (L) of animals measured in a nonanaesthetized, relaxed position. We use a relationship between postabdomen length and L to show that LWR's of Ontario and Scandinavian populations of H. gibberum differ. As such differences among lakes are the rule and not the exception, it is not safe to assume that published LWR's for zooplankton are widely applicable. Consideration of clutch size (CS) and a body fat index (BFI) in addition to L significantly improved estimates of the dry weight of Holopedium from Plastic Lake in central Ontario. This model provided more accurate estimates of Holopedium dry weight in 29 test lakes than the simple LWR, i.e. it had wider applicability. Predicted weights in the test lakes were further improved by consideration of lake water total phosphorus concentrations.

Comparison of the Phosphorus–Chlorophyll Relationships in Mixed and Stratified Lakes

1985 ◽  
Vol 42 (4) ◽  
pp. 831-835 ◽  
Author(s):  
E. T. Riley ◽  
E. E. Prepas
Keyword(s):  
Chlorophyll A ◽  
Total Phosphorus ◽  
Phosphorus Concentration ◽  
Total Phosphorus Concentration ◽  
Chlorophyll A Concentration ◽  
Chl A ◽  
Stratified Lakes ◽  
The Mean

Data from the literature were used to calculate separate regressions of summer chlorophyll a concentration ([Chl a]) on spring total phosphorus concentration ([TP]) for lakes that remain thermally stratified during the summer and lakes that mix intermittently during the summer. Significant differences were found in the spring [TP] – summer [Chl a] relationships for the two lake types (P < 0.05). The mean ratios of summer [TP] to spring [TP] were also significantly different in stratified and mixed lakes (P < 0.001); this difference is the explanation offered for why the spring [TP] – summer [Chl a] relationships were different in stratified and mixed lakes.

Factors Affecting the Relation Between Phosphorus and Chlorophyll a in Midwestern Reservoirs

1983 ◽  
Vol 40 (2) ◽  
pp. 192-199 ◽  
Author(s):  
Mark V. Hoyer ◽  
John R. Jones
Keyword(s):  
Chlorophyll A ◽  
Total Phosphorus ◽  
Suspended Solids ◽  
Phosphorus Concentration ◽  
Zooplankton Abundance ◽  
Factors Affecting ◽  
Inorganic Solids ◽  
Flushing Rate ◽  
Natural Lakes ◽  
The Mean

The mean chlorophyll a (mg/m3) yield per unit of total phosphorus (mg/m3) (P–C relation) in 96 midwest reservoirs and the variance about this yield was similar to relations for natural lakes reported in the literature. The remaining error term for this relation could not be reduced by adding variables for nitrogen, zooplankton abundance, or hydrologic flushing rate. In reservoirs with ratios of total nitrogen to total phosphorus of less than 10, nitrogen accounted for the same amount of variance in chlorophyll a as did phosphorus. Using partial regression path analysis, we found that when the concentration of phosphorus was held constant, increasing the concentration of inorganic suspended solids (mg/L) significantly decreased chlorophyll a. The following multivariate equation was developed to account for the effect of inorganic solids on the P–C relation:[Formula: see text]This equation accounted for 7% more variance than the univariate equation and the 95% predictive confidence interval, at an average phosphorus concentration, was reduced by 10%. This equation should be useful for predicting chlorophyll a in lakes with inorganic turbidities. When Secchi transparency data were regressed on both chlorophyll a and inorganic suspended solids, they accounted for 42% more variance in transparency than did chlorophyll a.Key words: lake trophic state, nitrogen, zooplankton, flushing rate, suspended solids, reservoirs

Effects of Supplementary Soil Nutrients on Hummock Grasses

1994 ◽  
Vol 42 (6) ◽  
pp. 687 ◽  
Author(s):  
BL Rice ◽  
M Westoby ◽  
GF Griffin ◽  
MH Friedel
Keyword(s):  
Soil Nutrients ◽  
Total Phosphorus ◽  
Soil Phosphorus ◽  
Nitrogen Concentration ◽  
Nutrient Content ◽  
Separate Experiment ◽  
Phosphorus Concentration ◽  
Absolute Amount ◽  
Available Soil Phosphorus ◽  
Fertiliser Application

Hummocks of Triodia basedowii E. Pritz, T. pungens R.Br. and Plectrachne schinzii Henr. were treated with ash and with standard and high applications of slow-release fertiliser. Following rain and the ensuing growth and flowering, the soils and the hummocks were sampled for biomass and for nutrient content, and compared to controls. In a similar but separate experiment, seed set in inflorescences was assessed for hummocks treated with standard fertiliser application, for hummocks treated by removal of neighbouring hummocks, and for controls. In the absence of nutrient addition, total topsoil nitrogen concentration was higher under hummocks than outside, whereas total topsoil phosphorus concentration was lower under hummocks than outside. The absolute amount of phosphorus in the hummock itself was insufficient to account for the depletion of phosphorus in topsoil under the hummock. Available soil phosphorus was about 1-4% of total phosphorus, and was generally highest towards the edge of hummocks. Additions of ash did not significantly affect soil nutrients, while addition of fertiliser produced substantial increases in total nitrogen and in available and total phosphorus. The increases did not extend to the area surrounding the hummock. The increases in soil nutrients did not result in significant increases in new green growth, or in inflorescence biomass or number. However, nutrients appear to have been taken up into the plants, including into old tissue, because there were increases in nutrient concentration in plant tissues, which sometimes were statistically significant and sometimes not. In the second experiment, neither increased soil nutrients nor removal of neighbours increased the number of inflorescences produced, or the proportion of florets that gave rise to filled grain.

Comparison of digestion methods for determination of total phosphorus in river sediments

2014 ◽  
Vol 68 (8) ◽  
Author(s):  
Jitka Malá ◽  
Marcela Lagová
Keyword(s):  
Total Phosphorus ◽  
River Sediment ◽  
River Sediments ◽  
Photometric Determination ◽  
Phosphorus Concentration ◽  
Interference Effects ◽  
Total Phosphorus Concentration ◽  
The Mean ◽  
Digestion Methods

AbstractIn this study, four digestion methods used to determine total phosphorus in river sediments, including Na2CO3 fusion, the H2SO4 and H2SO4 + H2O2 methods and the SMT protocol were investigated. Interference effects of iron, calcium and organic matter in river sediments, and the substances contained in the digestion agents on the photometric determination of the phosphates were analysed. The digestion methods were tested on ten river sediment samples. Statistical analysis of the results showed significant differences between sample treatments relating to the mean total phosphorus concentration.

Lake Paranoá, Brasília, Brazil: Integrated Management Plan for its Restoration

1992 ◽  
Vol 27 (2) ◽  
pp. 271-286 ◽  
Author(s):  
Sonia Paulino Mattos ◽  
Irene Guimarães Altafin ◽  
Hélio José de Freitas ◽  
Cristine Gobbato Brandão Cavalcanti ◽  
Vera Regina Estuqui Alves
Keyword(s):  
Total Phosphorus ◽  
Drainage Basin ◽  
Integrated Management ◽  
Algal Growth ◽  
Nutrient Content ◽  
Management Plan ◽  
Cylindrospermopsis Raciborskii ◽  
Phosphorus Concentration ◽  
Limiting Factor ◽  
Total Phosphorus Concentration

Abstract Built in 1959, Lake Paranoá, in Brasilia, Brazil, has been undergoing an accelerated process of nutrient enrichment, due to inputs of inadequately treated raw sewage, generated by a population of 600,000 inhabitants. Consequently, it shows high nutrient content (40 µg/L of total phosphorus and 1800 µg/L of total nitrogen), low transparency (0.65 m) and high levels of chlorophyll a (65 µg/L), represented mainly by Cylindrospermopsis raciborskii and sporadic bloom of Microcystis aeruginosa, which is being combatted with copper sulphate. With the absence of seasonality and a vertical distribution which is not very evident, the horizontal pattern assumes great importance in this reservoir, in which five compartments stand out. Based on this segmentation and on the identification of the total phosphorus parameter as the limiting factor for algal growth, mathematical models were developed which demonstrate the need for advanced treatment of all the sewage produced in its drainage basin. With this, it is expected that a process of restoration will be initiated, with a decline in total phosphorus concentration to readings below 25 µg/L. Additional measures are proposed to accelerate this process.

Solid, slightly soluble phosphorus compounds as nutrient source in activated sludge treatment of forest industry wastewaters

1997 ◽  
Vol 35 (2-3) ◽  
pp. 131-138 ◽  
Author(s):  
Pirjo-Riitta Rantala ◽  
Hannu Wirola
Keyword(s):  
Activated Sludge ◽  
The Other ◽  
Phosphorus Compounds ◽  
Forest Industry ◽  
Phosphorus Concentration ◽  
Nutrient Source ◽  
Sludge Treatment ◽  
Grain Sizes ◽  
Soluble Phosphorus ◽  
The Mean

The aim of the study was to determine if solid, slightly soluble compounds can be used as nutrient source in activated sludge treatment plants instead of liquid phosphoric acid. Four different solid materials were tested in lab-scale solubility tests to find compounds which are least soluble. Two materials were chosen for further studies: apatite and raw phosphate. The use of apatite and raw phosphate as nutrient source was studied in lab-scale activated sludge reactors along with a control reactor where phosphorus was added in liquid form. The phosphorus dosage, measured as elementary phosphorus, was the same for all three reactors. The reactors were fed with pre-clarified chemi-thermomechanical pulp mill (CTMP) wastewater. There were no significant differences in the reductions of organic matter between the three reactors. The mean effluent concentration of total phosphorus was 3 mg P/l in the control reactor and less than 1 mg P/1 in the other two reactors. The soluble phosphorus concentration was more than 2 mg P/l in the control reactor and less than 0.5 mg P/l in the other two. Apatite was an even better nutrient source than raw phosphate. Further lab-scale tests were conducted using two different grain sizes of apatite. No significant differences were found between the studied grain sizes (&lt;0.074 mm and 0.074 mm-0.125 mm). Apatite was then used in full-scale at a CTMP-mill two different times. The experiments showed that the mean concentrations of phosphorus can be reduced radically by using apatite as a nutrient source instead of liquid phosphorus. Solid phosphorus compounds are a viable alternative to reduce the phosphorus load from forest industry wastewater treatment plants.

scholarly journals The Combined Effects of Fine Particulate Matter and Temperature on Preterm Birth in Seoul, 2010–2016

2021 ◽  
Vol 18 (4) ◽  
pp. 1463
Author(s):  
Youngrin Kwag ◽  
Min-ho Kim ◽  
Shinhee Ye ◽  
Jongmin Oh ◽  
Gyeyoon Yim ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Preterm Birth ◽  
Pregnant Women ◽  
Low Temperatures ◽  
Fine Particulate Matter ◽  
Temperature Data ◽  
Fine Particulate ◽  
The Mean ◽  
Pm2.5 Exposure ◽  
Pm2.5 Concentration

Background: Preterm birth contributes to the morbidity and mortality of newborns and infants. Recent studies have shown that maternal exposure to particulate matter and extreme temperatures results in immune dysfunction, which can induce preterm birth. This study aimed to evaluate the association between fine particulate matter (PM2.5) exposure, temperature, and preterm birth in Seoul, Republic of Korea. Methods: We used 2010–2016 birth data from Seoul, obtained from the Korea National Statistical Office Microdata. PM2.5 concentration data from Seoul were generated through the Community Multiscale Air Quality (CMAQ) model. Seoul temperature data were collected from the Korea Meteorological Administration (KMA). The exposure period of PM2.5 and temperature were divided into the first (TR1), second (TR2), and third (TR3) trimesters of pregnancy. The mean PM2.5 concentration was used in units of ×10 µg/m3 and the mean temperature was divided into four categories based on quartiles. Logistic regression analyses were performed to evaluate the association between PM2.5 exposure and preterm birth, as well as the combined effects of PM2.5 exposure and temperature on preterm birth. Result: In a model that includes three trimesters of PM2.5 and temperature data as exposures, which assumes an interaction between PM2.5 and temperature in each trimester, the risk of preterm birth was positively associated with TR1 PM2.5 exposure among pregnant women exposed to relatively low mean temperatures (<3.4 °C) during TR1 (OR 1.134, 95% CI 1.061–1.213, p < 0.001). Conclusions: When we assumed the interaction between PM2.5 exposure and temperature exposure, PM2.5 exposure during TR1 increased the risk of preterm birth among pregnant women exposed to low temperatures during TR1. Pregnant women should be aware of the risk associated with combined exposure to particulate matter and low temperatures during TR1 to prevent preterm birth.

scholarly journals Computational Evaluation of Shock Wave Interaction with a Cylindrical Water Column

2021 ◽  
Vol 11 (11) ◽  
pp. 4934
Author(s):  
Viola Rossano ◽  
Giuliano De Stefano
Keyword(s):  
Shock Wave ◽  
Water Column ◽  
Wave Interaction ◽  
Navier Stokes ◽  
Plane Shock ◽  
Governing Equations ◽  
Computational Evaluation ◽  
Air Water Interface ◽  
The Mean ◽  
The Impact

Computational fluid dynamics was employed to predict the early stages of the aerodynamic breakup of a cylindrical water column, due to the impact of a traveling plane shock wave. The unsteady Reynolds-averaged Navier–Stokes approach was used to simulate the mean turbulent flow in a virtual shock tube device. The compressible flow governing equations were solved by means of a finite volume-based numerical method, where the volume of fluid technique was employed to track the air–water interface on the fixed numerical mesh. The present computational modeling approach for industrial gas dynamics applications was verified by making a comparison with reference experimental and numerical results for the same flow configuration. The engineering analysis of the shock–column interaction was performed in the shear-stripping regime, where an acceptably accurate prediction of the interface deformation was achieved. Both column flattening and sheet shearing at the column equator were correctly reproduced, along with the water body drift.

Sign in / Sign up

Export Citation Format

Share Document