2. Articole

Permanent URI for this collectionhttps://msuir.usm.md/handle/123456789/13413

Browse

Subject: search.filters.subject.water quality

Search Results

Now showing 1 - 4 of 4
  • Thumbnail Image
    Item
    INFLUIENȚA RÂURILOR RĂUT, BÂC ȘI BOTNA ASUPRA COMPONENȚEI FITOPLANCTONULUI ȘI CALITăȚII APEI SECTORULUI INFERIOR AL FL. NISTRU
    (CEP USM, 2024) Ungureanu, Laurenţia; Tumanova, Daria
    The article presents the results of the investigations on diversity and quantitative parameters of planktonic algae in three rivers: Raut, Bâc and Botna, which are the tributaries of the Dniester River. In tributaries of Dniester River phytoplankton was represented by the four groups: Cyanophyta, Bacillariophyta, Euglenophyta and Chlorophyta. It was established that the biggest negative effect on the Dniester River influences the water coming from the Bâc River according to the quantitative parameters (number of species and biomass) of phytoplankton as well as the saprobity index of planktonic algae. The values of the saprobic index of this tributary fell within the limits of water quality classes III (polluted). The water quality of the Răut and Botna tributaries according to the values of the saprobic index, being assigned to class II (moderately polluted).
  • Thumbnail Image
    Item
    DINAMICA FORMELOR DE AZOT ÎN FLUVIUL NISTRU
    (CEP USM, 2024) Borodin, Natalia; Bagrin, Nina
    The present investigation provides data of some ions, namely N-NH4+, N-NO2-, N-NO3-, Nmin, Norg, Ntot, in water samples collected from the Dniester River during spring in 2024. In the study are examines the spatial dynamics of the forms of mineral nitrogen, total nitrogen and the correlation between organic and mineral nitrogen. The content of nitrates, nitrites and ammonium ions was determined by the spectrophotometric method to the spectrophotometer UV-VIS Specord 210 Plus. The pH, temperature, have also been determined to asses the chemical status and pollution levels of these water sources. Limits of ammonium ion concentration in the Dniester River varied between 0.045 mg N/L and 0.722 mg N/L, nitrite ions 0.007 mg N/L and 0.031mg N/L, nitrate ions 0.083 mg N/L-1.492 mg N/L. Higher ammonium concentrations could be observed at the point Vadul-lui-Vodă and it was 0.722 mg N/L, which gave the water the 3rd quality class (moderately polluted). The main form of nitrogen is nitrate ion. Along all the Dniester River there is a dominance of mineral nitrogen which makes up more than 50% of the total nitrogen content.
  • Thumbnail Image
    Item
    DIVERSITY AND FUNCTIONING OF PHYTOPLANKTON IN THE DUBASARI WATER ACCUMULATION RESERVOIR
    (CEP USM, 2014) Ungureanu, Laurentia; Toderas, Ion; Tumanova, Daria; Ungureanu, Grigore
    During the period 2009-2011 the Dubasari lake phytoplankton was represented by a total of 90 species and intra-specific taxons, where Bacillariophyta, Cyanophyta and Chlorophyta species are prevailing. Numbers of phytoplankton ranged from 6.16 to 13.76 mln.cel/l with the biomass from 4.27 to 18.41 g/m3 in the spring and from 2.13 to 35.99 mln.cel/l with the biomass from 7.02 to 24.13 g/m3 in the summer, and from 3.5 to 13.3 mln.cel/l with the biomass from 2.91 to 17.61 during autumn. Share in the phytoplankton numbers belongs to cianofite algae, and in the algal biomass to bacilariofite algae. The maximum intensity of production processes was recorded in the summer, primary production values being located within 0.84 to 9.95 gO2/m-2 24 h. Seasonal and spatial fluctuations in lake primary production are accompanied by fluctuations in phytoplankton biomass, community structure of plankton algae succession, changes in nutrient elements concentrations and water transparency values oscillations. There were established variations of the saprobe index values within 1.68 to 2.72. Most saprobe index values were within limits of the β-mezosaprobe zone and indicate attribution to the water the quality classes 3a -”satisfactory pure” – 3b “moderately polluted”.
  • Thumbnail Image
    Item
    STAREA ECOLOGICĂ ȘI IHTIOFAUNA A LACURILOR DIN REZERVAȚIA ȘTIINȚIFICĂ ”PLAIUL FAGULUI”
    (CEP USM, 2024) Bulat, Dumitru; Bulat, Denis; Zubcov, Elena; Ungureanu, Laurenția; Bagrin, Nina; Munjiu, Oxana; Tumanova, Daria; Lebedenco, Liubovi
    The paper represents the results of hydrobiological and hydrochemical research carried out in the lakes located on the territory of the “Plaiul Fagului” scientific reserve. These investigati ons can serve as a model for the ecological inventory of all aquatic ecosystems within the State Protected Natural Areas fund of the Republic of Moldova. For the sustainable exploitation of aquatic resources in natural reserves, continuous scientific monitoring of these aquatic resources is necessary.