scholarly journals Characteristics of bottom sediments of Lake Widryńskie

2012 ◽  
Vol 12 (4) ◽  
pp. 207-212 ◽  
Author(s):  
Daniel Szymański ◽  
Julita Dunalska ◽  
Michał Łopata ◽  
Izabela Bigaj ◽  
Rafał Zieliński

AbstractThe aim of this study was to determine the chemical composition of Lake Widryńskie bottom sediments (max. depth. 27.0 m, area 123.9 ha). The sampling of bottom sediments was conducted once, on 16 August 2010. Sampling was made in 10 specific areas. Among the 10 samples, 4 samples were taken from the littoral and sublittoral zones, while the rest were taken from the profundal zone. The dominant component of the sediments was silica and calcium carbonates were subdominant. Based on the survey, it was determined that silica occurred in greater numbers in littoral sediments, while in sublittoral sediments there was increased participation in the chemical composition of organic matter. The elements that build a capacity complex were a small percentage of the dry weight of sediment. Sediment from the vicinity of inflows contains higher amounts of silica, which confirmed the impact of the catchment on the chemical composition of sediments.

1953 ◽  
Vol 10 (5) ◽  
pp. 283-291 ◽  
Author(s):  
Herman Kleerekoper

The rate and the thoroughness of the decomposition of plankton remains are important factors in the cycles of some nutrients in lakes. Experimental data on the mineralization of plankton in vitro are available, especially of marine organisms, but quantitative observations on this process in nature are not mentioned in the literature. This paper presents the results of such observations, made in Lake Lauzon, Montcalm County, P.Q., by means of a sediment collector described in an earlier paper. The chemical composition of plankton, of sediment collected at the 11-meter level, and of surface bottom sediments are studied. Most of the decomposition of the sinking detritus takes place in the epilimnion of the lake. Sediment collected at the 11-meter level, in weekly intervals, shows a remarkable resemblance in composition with the surface bottom sediments. Most of the nitrogen is liberated in the upper 11 meters of water. The liberation of phosphorus seems to be slower and the surface bottom sediments are actually enriched with this element. Silica is enriched at both the 11-meter level and the bottom of the lake, mainly through the settling of diatom frustules. Hydrolysis of organic matter in the upper 11-meter column of the lake decreases in the course of the summer. Mineralization seems to be practically halted in the oxygen-poor hypolimnion.


Agronomy ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1976
Author(s):  
Filipa Mandim ◽  
Spyridon A. Petropoulos ◽  
Kyriakos D. Giannoulis ◽  
Celestino Santos-Buelga ◽  
Isabel C. F. R. Ferreira ◽  
...  

The present study evaluated the effect of maturity stage on the chemical composition of cardoon bracts. Plant material was collected in Greece at eight different maturation stages (C1–C8) and the chemical composition was analyzed in regard to lipidic fraction and the content in fatty acids, tocopherols, organic acids, and free sugars. Samples of late maturity (C6–C8) revealed the lowest lipidic content, while a total of 29 fatty acids was identified in all the samples, with palmitic, stearic, oleic, and eicosatrienoic acids present in the highest levels depending on harvesting time. Immature (C1) and mature (C8) bracts were more abundant in saturated fatty acids (SFA) than bracts of medium-to-late maturity (C5, C6), where the monounsaturated fatty acids (MUFA) were the prevalent class. The α- and γ-tocopherols were the only identified isoforms of vitamin E, while the highest content was observed in sample C8 (199 µg/100 g dry weight (dw). The detected organic acids were oxalic, quinic, malic, citric, and fumaric acids, while fructose, glucose, sucrose, trehalose, and raffinose were the main detected sugars. The results of the present study allowed us to reveal the effect of maturity stage on cardoon bracts chemical composition and further valorize this byproduct by improving its bioactive compounds content.


2003 ◽  
Vol 60 (7) ◽  
pp. 888-896 ◽  
Author(s):  
Martin Kainz ◽  
Marc Lucotte ◽  
Christopher C Parrish

Relationships between organic matter (OM) compounds and methyl mercury concentrations ([MeHg]) have been examined in littoral and offshore sediments of Lake Lusignan (Québec). The highest [MeHg] were generally found at the sediment–water interface with exceptionally high concentrations at littoral sites (5.8 ± 1.3 ng·g dry weight–1), which were four times more elevated than at offshore sites (1.6 ± 0.77 ng·g dry weight–1). Source-specific fatty acid (FA) biomarkers identified that littoral sediments contained more than twice as much terrestrial and bacterial OM compounds than offshore sediments, whereas the amount of labile algal OM was three times higher at littoral sites. Results indicate that [MeHg] were higher in the presence of labile OM substrates, and the amount of terrestrial OM compounds could not predict [MeHg]. Correlations between [MeHg] and FA of Desulfovibrio desulfuricans (a sulfate-reducing bacterium producing MeHg) could significantly account for 36% of [MeHg] at offshore sites; however, no significant relationships were found at littoral sites. This study illustrates that the microbial dynamics involved in producing and degrading MeHg in lacustrine sediments are complex and cannot be predicted solely by the quantification of FA biomarkers in D. desulfuricans or by biomarkers in the OM itself.


2010 ◽  
Vol 10 (3-4) ◽  
pp. 139-145 ◽  
Author(s):  
Katarzyna Kowalczewska-Madura ◽  
Renata Dondajewska ◽  
Ryszard Gołdyn

Total phosphorus and organic matter content in bottom sediments of lake under restoration measures with iron treatmentRusałka Lake is a shallow, man-made, strongly eutrophicated reservoir, being a place of recreational activities for Poznan citizens. Restoration measures with the use of iron sulphate were conducted in years 2006-2007. Phosphorus and organic matter concentrations in lake sediments were analyzed in years 2005-2007 at two research stations (profundal and littoral) to determine its changes under the influence of restoration. Greater phosphorus concentrations were noted in profundal (max 1.55 mg P g-1dry weight (DW)) than in littoral (max 0.98 mg P g-1DW). An increase of P amount in sediment was observed after iron treatment. Among phosphorus fractions Res-P dominated, i.e. phosphorus biologically unavailable for organisms. Organic matter content reached 23.1% in profundal, while 14.8% in littoral. Its amount decreased in following years.


2018 ◽  
Author(s):  
Christina Theodosi ◽  
Maria Tsagkaraki ◽  
Pavlos Zarmpas ◽  
Eleni Liakakou ◽  
Georgios Grivas ◽  
...  

Abstract. In an attempt to take effective action towards mitigating pollution episodes in the Greater Athens Area (GAA), precise knowledge of PM2.5 composition and their sources is a prerequisite. Thus, a two year chemical composition data set from aerosol samples collected in an urban-background site of central Athens, from December 2013 till March 2016, has been obtained and Positive Matrix Factorization (PMF) was applied in order to identify and apportion fine aerosols to their sources. A total of 850 aerosol samples, were collected on a 12 to 24 h basis and analyzed for major ions, trace elements, organic and elemental carbon, allowing us to further assess the impact of residential heating as a source of air pollution over the GAA. The ionic and carbonaceous components were found to constitute the major fraction of the PM2.5 aerosol mass. The annual contribution of the Ion Mass (IM), Particulate Organic Mass (POM), dust, Elemental Carbon (EC) and Sea Salt (SS) were calculated at 31 %, 34 %, 18 %, 8 % and 3 %, respectively. However, carbonaceous aerosols (POM + EC) and IM exhibited considerable seasonal variation. In winter, IM was estimated down to 23 %, with POM + EC being the dominant component accounting for 48 % of the PM2.5 mass, while in summer IM was the dominant component (42 %), followed by carbonaceous aerosols 37 %. Results from samples collected on a 12 h basis (day and night) during the 3 intensive winter campaigns indicated the impact of heating on the levels of a series of compounds. Indeed PM2.5, EC, POM, NO3−, C2O42−, nssK+ and selected trace metals including Cd and Pb were increased by almost a factor of 4 during night compared to day, highlighting the importance of heating on air quality of the GAA. Furthermore, in order to better characterize winter-time aerosol sources in the city centre of Athens and quantify the input of biomass burning as a source to winter night-time PM2.5 concentrations, source apportionment was performed. Τhe data can be interpreted on the basis of six sources namely biomass burning (32 %), vehicular emissions (19 %), heavy oil combustion (7 %), regional secondary (20 %), marine aerosol (9 %) and dust particles (8 %). With specific emphasis on night to day contrasts their contributions shifted from 19, 19, 8, 30, 11 and 9 % of the PM2.5 mass during day to 39, 19, 6, 14, 7 and 6 % during night, underlining the significance of biomass burning as the main contributor to fine particle levels during night-time.


1972 ◽  
Vol 78 (3) ◽  
pp. 477-485 ◽  
Author(s):  
J. Fernandez Carmona ◽  
J. F. D. Greenhalgh

SUMMARYThe main objective of the experiments described was to compare the effects of milling straw and/or soaking or spraying it with sodium hydroxide on its digestibility and acceptability to sheep. Some preliminary trials were made in the laboratory to compare different alkali treatments with respect to losses of organic matter, chemical composition and digestibility in vitro.In a feeding trial of Latin-square design, involving six sheep, the following treatments of barley straw were compared: C, chopped; M, coarsely-milled; OIL, chopped and soaked in 1·5% NaOH (9 g NaOH/100 g straw); CIH, chopped and soaked in 3·0% NaOH (18 g/100 g straw); CS, chopped and sprayed with 16 % NaOH (8 g/100 g straw); MS, milled and sprayed with 16 % NaOH. After treatments OIL and CIH the straw was washed; this caused losses of organic matter of 28 and 32%, respectively. For CS and CM the excess NaOH was neutralized by addition of 7·4 ml propionic acid/100 g straw.The straws were given with supplements of purified soya protein, minerals and vitamins. The digestibility of energy for the straw was (%): C, 40·4; M, 39·1; CIL, 65·0; CIH, 64·4; CS, 57·3; MS, 60·2. Dry-matter intake (g/kg W0·75 per day) was: C, 26·7; M, 36·2; CIL, 37·1; CIH, 44·2; CS, 48·4; MS 53·6.


2021 ◽  
Vol 958 (1) ◽  
pp. 012017
Author(s):  
D Zhou ◽  
O G Savichev

Abstract Considering the dilution of sewage and the interaction between river water and bottom sediments, a mathematical model for the conversion of pollutants in water bodies has been developed. Taking the small rivers in northern Vietnam (Ban Thi River and Dai River in the Red River Basin) as an example, it shows that more than 60% of the chemical composition of the river waters studied is determined by the interaction of the following factors: Co-precipitation of sediments and trace elements on solid particles, and sediments at the bottom of the river. The impact of water runoff is first manifested in the change of solid runoff, and to a lesser extent in the process of regulating the water, which takes longer to establish equilibrium in the solution. On the basis of the proposed model, a simplified version of the model and a standardized pollutant discharge method have been developed for whether there is an option of river water chemical composition observation data. In this case, the influence of interaction with bottom sediments is indirectly considered through the structure of the model and its parameter values. The simplified model was tested with the Jinjiang River in the Poyang Lake Basin as an example.


2022 ◽  
Author(s):  
E. Ortega-Jiménez ◽  
F. Sedano ◽  
F. Espinosa

AbstractMollusc communities are getting endangered in the aftermath of urban sprawl because artificial structures do not surrogate natural substrates. In this study, we compared the diversity, community and trophic arrangements of molluscs among different models of artificial substrate and their adjacent natural rock, to detect relationships between some abiotic variables and the mollusc communities. Complexity, chemical composition and age were tested as potential drivers of the community. Diversity, community and trophic structure differed between natural and artificial substrates. Complexity at the scale of cm was detected as the most important factor driving the community structure. In addition, a chemical composition based on silica and/or scarce calcium carbonates seems to be relevant for molluscs, as well as for the secondary substrate where they inhabit. However, age did not seem to be a driving factor. Among the different artificial structures, macroscale complexity was detected as the main factor diverging a drastically poor community at seawall from other artificial structures. In this context, macro and microscale complexity, chemical composition and mineral type are variables to consider in future designs of artificial substrates.


Author(s):  
Olga Kostic ◽  
Miroslava Mitrovic ◽  
Pavle Pavlovic

This study investigates the impact of organic matter from Douglas fir (Pseudotsuga menziesii [Mirb.] Franco) on the amount and composition of humus in acid brown soil in a climatoregional beech forest (Fagetum moesiacae montanum B. Jov. 1967 s.l.) on Mt. Maljen. To accomplish this objective, we performed a one-year litterbag decomposition experiment with litterfall from Fagus moesiaca and Pseudotsuga menziesii. The quantitative and qualitative content of humus and the intensity of the decomposition process of organic mat?ter from beech and Douglas fir were analysed. Less humus was found during the experiment under Douglas fir than under autochthonous beech at the control site, as well as a decreasing trend for humus levels and quality (unfavourable chemical composition). It was concluded that these changes, caused by the effects of the clearcutting of beech and, in the future, of Douglas fir, and the slower decomposition of organic matter from Douglas fir will contribute to further degradation of the beech habitat on Mt. Maljen in terms of productivity.


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