Determination of phosphorus concentration threshold for algal growth in eutrophic Chaohu Lake, china

1992 ◽  
Vol 27 (2) ◽  
pp. 433-443
Author(s):  
C. Yin ◽  
Z. Lan ◽  
M. Zhao ◽  
H. Bernhardt
Keyword(s):  
Algal Growth ◽  
Phosphorus Concentration ◽  
Chaohu Lake ◽  
Concentration Threshold

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.

Novel sliding hybrid microchip detection system for determination of whole blood phosphorus concentration

2021 ◽  
Vol 419 ◽  
pp. 129592
Author(s):  
Chin-Chung Tseng ◽  
Szu-Jui Chen ◽  
Song-Yu Lu ◽  
Chien-Hsuan Ko ◽  
Ju-Ming Wang ◽  
...  
Keyword(s):  
Whole Blood ◽  
Detection System ◽  
Phosphorus Concentration

Fast Determination of Phosphorus Concentration in Phosphogypsum Waste Using Calibration-Free LIBS in Air and Helium

2021 ◽  
Author(s):  
Khaled Elsayed ◽  
Walid Tawfik ◽  
Ashraf E M Khater ◽  
Tarek S Kayed ◽  
Mohamed Fikry
Keyword(s):  
Complete Analysis ◽  
Phosphorus Concentration ◽  
Stark Broadening ◽  
Breakdown Spectroscopy ◽  
P Concentration ◽  
Characteristic Lines ◽  
Laser Induced Breakdown ◽  
Novel Method ◽  
Calibration Free

Abstract This work represents a novel method to determine phosphorus (P) concentration in phosphogypsum (PG) waste samples using calibration-free laser-induced breakdown spectroscopy (LIBS). A 50 mJ Q-switched Nd: YAG laser has generated the PG LIBS spectrum. Spectroscopic analysis of plasma evolution has been characterized by electron density Ne and electron temperature Te using the emission intensity and stark broadening for P I characteristic lines 213.61, 214.91, and 215.40 nm under non-purged (air) and purged (helium) conditions. It was found that both Te and Ne have significant changes linearly with P concentrations 4195, 5288, 6293, and 6905 ppm. The values of plasma Te and Ne increased from about 6900 to 10000 K and 1.1×1017 to 3.4×1017 cm− 3, respectively, for the non-purged PG. On the other hand, Te and Ne ranged from 8200 to 11000 K and 1.4×1017 to 3.5×1017 cm− 3, respectively, for the PG purged with helium. It is concluded that Te and Ne values represent a fingerprint plasma characterization for a given P concentration in PG samples, which can be used to identify P concentration without a PG's complete analysis. These results demonstrate a new achievement in the field of spectrochemical analysis of environmental applications.

scholarly journals Feces from Piscivorous and Herbivorous Birds Stimulate Differentially Phytoplankton Growth

Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2567 ◽  
Author(s):  
Jolita Petkuviene ◽  
Diana Vaiciute ◽  
Marija Katarzyte ◽  
Iveta Gecaite ◽  
Giorgio Rossato ◽  
...  
Keyword(s):  
Heterotrophic Bacteria ◽  
Algal Growth ◽  
Major Effect ◽  
Phytoplankton Growth ◽  
Curonian Lagoon ◽  
Phosphorus Concentration ◽  
Direct Role ◽  
Algal Groups ◽  
Reactive Phosphorus

Aquatic birds may impact shallow ecosystems via organic and nutrient enrichment with feces. Such input may alleviate nutrient limitation, unbalance their ecological stoichiometry, and stimulate primary production. Herbivorous and piscivorous birds may produce different effects on aquatic ecosystems due to different physiology, diet and feces elemental composition. We analyze the effects of droppings from swans (herbivorous) and cormorants (piscivorous) on phytoplankton growth via a laboratory experiment. These birds are well represented in the Curonian Lagoon, where they form large colonies. As this lagoon displays summer algal hyper-blooms, we hypothesize an active, direct role of birds via defecation on algal growth. Short-term incubations of phytoplankton under low and high feces addition produces different stimulation of algal growth, significantly higher with high inputs of cormorant feces. The latter produces a major effect on reactive phosphorus concentration that augments significantly, as compared to treatments with swan feces, and determines an unbalanced, N-limited stoichiometry along with the duration of the experiment. During the incubation period, the dominant algal groups switch from blue-green to green algae, but such switch is independent of the level of feces input and from their origin. Heterotrophic bacteria also are stimulated by feces addition, but their increase is transient.

Study on Phosphorus Distribution from Sediment of Different Trophic Area of Taihu Lake and its Temporal Changes

2013 ◽  
Vol 295-298 ◽  
pp. 1663-1666
Author(s):  
Jian Hang Qu ◽  
Xiao Bing He ◽  
Hai Feng Li ◽  
Huan Chen Zhai ◽  
Yuan Sen Hu
Keyword(s):  
Taihu Lake ◽  
Algal Growth ◽  
Eutrophic Lake ◽  
Temporal Changes ◽  
Phosphorus Concentration ◽  
Lower Grade ◽  
Lake Area ◽  
Overlying Water ◽  
Phosphorus Forms ◽  
Water Eutrophication

Phosphorus is the key restraining factor for algal growth and water eutrophication, which is a global problem of environmental pollution. Using a sequential phosphorus extraction method, the phosphorus forms in sediment and their distribution from different trophic area of Taihu Lake (China) and their temporal changes were studied. Results showed that, concentration of Fe-P in sediment was the highest and successively Al-P, which was much higher than that of Ca2-P, Ca10-P, Ca8-P and O-P. All the phosphorus forms were more abundant in sediment 16# of eutrophic lake area, higher than that of moderate eutrophic and the lower-grade trophic area, with the last as relatively the lowest. Phosphorus concentration in June and September was much higher than that of March. Phosphorus in sediment of Taihu Lake had great releasing potential to the overlying water.

scholarly journals Iron as a disturbing factor in the determination of phosphate by the molybdenum blue method

1954 ◽  
Vol 26 (1) ◽  
pp. 159-168
Author(s):  
Armi Kaila
Keyword(s):  
Hydrochloric Acid ◽  
Sulphuric Acid ◽  
Ferrous Iron ◽  
Ferric Iron ◽  
Stannous Chloride ◽  
Phosphorus Concentration ◽  
Colour Intensity ◽  
Molybdenum Blue ◽  
Fading Effect

The interference of ferric and ferrous iron in the determination of phosphate by the molybdenum blue method has been studied. It was found that the presence of ferric iron in the solutions could cause either an increase or a decrease in the colour intensity depending on the amount of stannous chloride applied and on the acid and molybdate concentrations in the reagent. Also the phosphorus concentration exerted its effect upon the course of the errors. If the original modification of Truog and Meyer was employed, generally, the most convenient way for the elimination of the interference of ferric iron was to dilute the solution. An increase in the amount of stannous chloride largely helped to prevent the fading effect of ferric iron, provided the phosphorus concentration was not lower than 0.25 ppm. When the effect of ferric iron upon the development of molybdenum blue at various concentrations of sulphuric acid and ammonium molybdate was studied, the observation was made that at each acidity there could be found a concentration of molybdate in which the effect of even fairly high amounts of ferric iron was almost negligible. In lower molybdate concentrations the presence of ferric iron caused an increase in the colour intensity, in higher molybdate concentrations the fading effect of ferric iron was marked. This most suitable level of the molybdate concentration depended to a certain degree on the phosphorus concentration of the solution and on the amount of stannous chloride applied. Fairly good results could be obtained, if the ratio of molybdate (expressed as mg/ml) to acid (expressed as normality) in the solution to be reduced was five times as high as the acidity of the solution to be reduced (expressed as its normality), e.g. 4 in 0.8 N acid, 3.5 in 0.7 N acid, 3 in 0.6 N acid etc. Although it seemed to be fairly possible to avoid the interference of ferric iron by a proper choice of the concentrations of acid and molybdate and of the amount of stannous chloride applied, the fading effect of ferrous iron could not be prevented, if only sulphuric acid was used in the reagents. But the substitution of sulphuric acid by hydrochloric acid totally prevented the fading effect of ferrous iron. On the contrary, a slight increase in the colour intensity was demonstrated. This was true also when only one half of the acid present was hydrochloric acid. It was found that this mixture of sulphuric acid and hydrochloric acid in the molybdate reagent offers an available way for the elimination of the disturbing effect of iron.

scholarly journals A Rapid HPLC-UV Protocol Coupled to Chemometric Analysis for the Determination of the Major Phenolic Constituents and Tocopherol Content in Almonds and the Discrimination of the Geographical Origin

Molecules ◽  
2021 ◽  
Vol 26 (18) ◽  
pp. 5433
Author(s):  
Natasa P. Kalogiouri ◽  
Petros D. Mitsikaris ◽  
Dimitris Klaoudatos ◽  
Athanasios N. Papadopoulos ◽  
Victoria F. Samanidou
Keyword(s):  
Phenolic Compounds ◽  
Geographical Origin ◽  
Principal Component ◽  
Syringic Acid ◽  
Tocopherol Content ◽  
Reversed Phase ◽  
Uv Detector ◽  
Phenolic Constituents ◽  
Concentration Threshold

Reversed phase-high-pressure liquid chromatographic methodologies equipped with UV detector (RP-HPLC-UV) were developed for the determination of phenolic compounds and tocopherols in almonds. Nineteen samples of Texas almonds originating from USA and Greece were analyzed and 7 phenolic acids, 7 flavonoids, and tocopherols (−α, −β + γ) were determined. The analytical methodologies were validated and presented excellent linearity (r2 > 0.99), high recoveries over the range between 83.1 (syringic acid) to 95.5% (ferulic acid) for within-day assay (n = 6), and between 90.2 (diosmin) to 103.4% (rosmarinic acid) for between-day assay (n = 3 × 3), for phenolic compounds, and between 95.1 and 100.4% for within-day assay (n = 6), and between 93.2–96.2% for between-day assay (n = 3 × 3) for tocopherols. The analytes were further quantified, and the results were analyzed by principal component analysis (PCA), and agglomerative hierarchical clustering (AHC) to investigate potential differences between the bioactive content of almonds and the geographical origin. A decision tree (DT) was developed for the prediction of the geographical origin of almonds proposing a characteristic marker with a concentration threshold, proving to be a promising and reliable tool for the guarantee of the authenticity of the almonds.

scholarly journals Fast determination of phosphorus concentration in phosphogypsum waste using calibration-free LIBS in air and helium

2022 ◽  
Vol 54 (2) ◽  
Author(s):  
Khaled Elsayed ◽  
Walid Tawfik ◽  
Ashraf E. M. Khater ◽  
Tarek S. Kayed ◽  
Mohamed Fikry
Keyword(s):  
Phosphorus Concentration ◽  
Fast Determination ◽  
Calibration Free ◽  
Phosphogypsum Waste
Sign in / Sign up

Export Citation Format

Share Document