The composition of phytoplankton as an indicator of the ecological state of the middle course of the Ural River and its tributaries

The article presents the results of the analysis of the systematic structure of the algae flora of the studied reservoirs of the Orenburg region. The revealed richness of flora includes 104 species and varieties belonging to 7 divisions, 12 classes, 23 orders, 32 families, 58 genera. The dominant divisions are Chlorophyta, Bacillariophyta and Cyanophyta. The total number of microalgae at the study points was dependent on the anthropogenic load on the reservoir. Certain indices of saprobity of reservoirs indicate the presence of dissolved organic matter in the bulk of the studied reservoirs and pollution of natural waters. Keywords: NATURAL RESERVOIRS, WATER QUALITY, ALGOFLORA, URAL RIVER, SAPROBITY

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Estimation of the Natural Water Self-Purification Capacity from the Kinetic Standpoint

Chemistry Journal of Moldova ◽

10.19261/cjm.2008.03(1).16 ◽

2008 ◽

Vol 3 (1) ◽

pp. 10-21

Author(s):

Gheorghe Duca ◽

Elena Bunduchi ◽

Viorica Gladchi ◽

Lidia Romanciuc ◽

Nelli Goreaceva

Keyword(s):

Water Quality ◽

Organic Matter ◽

Transition Metals ◽

Dissolved Organic Matter ◽

Natural Water ◽

Natural Waters ◽

Current Paper ◽

Biogeochemical Cycle

The current paper contains a synthesis of the processes of chemical auto-purification that take place in natural waters; examples of mechanisms of such processes occurring with participation of dissolved organic matter, oxidants of the biogeochemical cycle of oxygen and of transition metals including copper and iron are presented. The kinetic indicators of natural water quality are presented as well.

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Photochemical effects on the interaction of enzymes and dissolved organic matter in natural waters

Limnology and Oceanography ◽

10.4319/lo.2003.48.5.1818 ◽

2003 ◽

Vol 48 (5) ◽

pp. 1818-1824 ◽

Cited By ~ 23

Author(s):

Norman M. Scully ◽

Lars J. Tranvik ◽

William J. Cooper

Keyword(s):

Organic Matter ◽

Dissolved Organic Matter ◽

Natural Waters

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Optical Properties of Dissolved Organic Matter in Finnish and Estonian Lakes

Hydrology Research ◽

10.2166/nh.2003.0012 ◽

2003 ◽

Vol 34 (4) ◽

pp. 361-386 ◽

Cited By ~ 14

Author(s):

L. Sipelgas ◽

H. Arst ◽

K. Kallio ◽

A. Erm ◽

P. Oja ◽

...

Keyword(s):

Organic Matter ◽

Dissolved Organic Matter ◽

Natural Waters ◽

Mean Value ◽

Published Data ◽

Optical Parameters ◽

Exponential Approximation ◽

Absorption Coefficients ◽

Specific Absorption ◽

The Mean

The main objective of the present study is to test various methods for describing the absorption spectra of coloured dissolved organic matter (CDOM) and to determine the numerical values of some optical parameters of CDOM in lakes with diverse water quality. First, the parameters of an exponential model in different spectral intervals were determined. In addition, the suitability of some other models for the approximation of CDOM spectra was estimated. Specific absorption coefficients of CDOM were calculated from the absorption coefficients and dissolved organic carbon (DOC) concentrations. The experimental initial data were differences between spectral attenuation coefficients of filtered and distilled water. Two datasets were used: 1) for 13 Estonian and 7 Finnish lakes (altogether 404 spectra between 350 and 700 nm) measured by the Estonian Marine Institute (EMI); 2) for 10 Finnish lakes (73 spectra) measured by the Finnish Environment Institute (FEI). The spectra of CDOM absorption coefficients (aCDOM) were calculated from experimental data taking into account the correction due to scattering properties of colloids in the filtered water. The total content of CDOM in natural waters of Estonian and Finnish lakes was expressed by means of aCDOM at the wavelength of 380 nm. It varied significantly, from 0.71 to 19.5 m−1, the mean value (of all the investigated lakes) being around 6.6 m−1. Slopes of the exponential approximation varied widely, from 0.006 to 0.03 nm−1. Averaged over all lakes values of slope for the interval 380-500 nm obtained from the EMI dataset are close to those obtained from the FEI dataset: from 0.014 nm−1 (without correction) to 0.016-0.017 nm-1 (with different types of correction). These results are in good correspondence with most published data. Attempts to describe the spectra in the region of 350-700 nm by means of hyperexponential functions (∽ exp(-αλη)) show that: (1) η < 1 (in the case of traditional exponential approximation η = 1); (2) a promising idea is to seek the best fit only for wavelengths λ > λ1, where λ1 will be chosen taking into account the real shape of aCDOM spectra. The mean value of the specific absorption coefficient (a*CDOM) at the wavelength 380 nm obtained in this study (0.44 L mg−1 m−1) is close to the values published in the literature, if we assume that a*CDOM (380) is calculated using the data of dissolved organic matter (DOM). The optically non-active fraction of DOM in our study was high and therefore a*CDOM (380) was considerably higher (1.01 L mg−1 m−1) than a*CDOM (380). The results of the present work could be used in the modeling of underwater light field as well as in the interpretation of radiation measurements and optical remote sensing results.

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Complexation of Dissolved Organic Matter with Trace Metal Ions in Natural Waters

Photobiogeochemistry of Organic Matter - Environmental Science and Engineering ◽

10.1007/978-3-642-32223-5_9 ◽

2012 ◽

pp. 769-849 ◽

Cited By ~ 7

Author(s):

Khan M. G. Mostofa ◽

Cong-qiang Liu ◽

Xinbin Feng ◽

Takahito Yoshioka ◽

Davide Vione ◽

...

Keyword(s):

Organic Matter ◽

Dissolved Organic Matter ◽

Trace Metal ◽

Metal Ions ◽

Natural Waters ◽

Trace Metal Ions

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USE OF DISSOLVED ORGANIC MATTER BY MICROORGANISMS: FORMATION OF WATER QUALITY IN A POND OF A HIGH TROPHIC LEVEL

Fisheries ◽

10.37663/0131-6184-2020-5-25-29 ◽

2020 ◽

Vol 2020 (5) ◽

pp. 25-29

Author(s):

Anatoliy Sadchikov ◽

Sergey Ostroumov

Keyword(s):

Water Quality ◽

Organic Matter ◽

Organic Carbon ◽

Dissolved Organic Matter ◽

Trophic Level ◽

Aquatic Ecosystem ◽

High Trophic Level ◽

Bacterioplankton Community ◽

Algae And Bacteria

The role of algae and bacteria in the consumption and mineralization of dissolved organic matter (DOM) in a highly trophic aquatic ecosystem was studied. The phytoplankton and bacterioplankton community consumed 60% of added DOM in August and 56% of DOM in September. Of the uptaken DOM, a significant amount of organic carbon was mineralized. In August 42.7% and in September 29% of organic carbon (of the consumed organic matter) were used for respiration.

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Impact of forest harvesting on water quality and fluorescence characteristics of dissolved organic matter in eastern Canadian Boreal Shield lakes in summer

Biogeosciences ◽

10.5194/bg-12-6999-2015 ◽

2015 ◽

Vol 12 (23) ◽

pp. 6999-7011 ◽

Cited By ~ 3

Author(s):

P. Glaz ◽

J.-P. Gagné ◽

P. Archambault ◽

P. Sirois ◽

C. Nozais

Keyword(s):

Water Quality ◽

Organic Matter ◽

Dissolved Organic Matter ◽

Forest Harvesting ◽

Spectroscopic Techniques ◽

Clear Cutting ◽

Fluorescence Measurements ◽

Fluorescence Characteristics ◽

Boreal Shield ◽

Shield Lakes

Abstract. Forestry activities in the Canadian Boreal region have increased in the last decades, raising concerns about their potential impact on aquatic ecosystems. Water quality and fluorescence characteristics of dissolved organic matter (DOM) were measured over a 3-year period in eight eastern Boreal Shield lakes: four lakes were studied before, 1 and 2 years after forest harvesting (perturbed lakes) and compared with four undisturbed reference lakes (unperturbed lakes) sampled at the same time. ANOVAs showed a significant increase in total phosphorus (TP) in perturbed lakes when the three sampling dates were considered and in DOC concentrations when considering 1 year before and 1 year after the perturbation only. At 1 year post-clear cutting DOC concentrations were about 15 % greater in the perturbed lakes at ~ 15 mgC L−1 compared to 12.5 mgC L−1 in the unperturbed lakes. In contrast, absorbance and fluorescence measurements showed that all metrics remained within narrow ranges compared to the range observed in natural waters, indicating that forest harvesting did not affect the nature of DOM characterized with spectroscopic techniques. These results confirm an impact of forestry activities 1 year after the perturbation. However, this effect seems to be mitigated 2 years after, indicating that the system shows high resilience and may be able to return to its original condition in terms of water quality parameters assessed in this study.

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