magistrsko delo
Tanja Krivec (Author), Sonja Škornik (Mentor), Zdenka Mazej (Co-mentor)

Abstract

Namen magistrske naloge je bil ugotoviti odvisnost vsebnosti nekaterih onesnažil v vodi potoka Peklenščica od vrste dejavnosti v zaledju in od vremenskih razmer. Pri tem smo osnovne fizikalno-kemijske analize dopolnili s testom strupenosti z malo vodno lečo (Lemna minor). Vodni vzorci so bili odvzeti na petih lokacijah od izvira potoka Peklenščica do izliva v potok Trnavo, in sicer ob štirih vzorčenjih med novembrom 2013 in avgustom 2014. V laboratoriju smo opravljali analize teh vzorcev, in sicer meritve koncentracij nitratov, nitritov, celotnega fosforja in meritve pH-vrednosti. Najvišje koncentracije hranil smo izmerili ob spomladanskem vzorčenju, ki je bilo izvedeno v času po obilnih padavinah in gnojenju na Ponikovski planoti, najnižje pa pri zimskem vzorčenju, ko gnojenja in padavin na planoti ni bilo. Odziv male vodne leče na onesnažila v vodnih vzorcih smo ocenjevali s spremljanjem njene rasti v skladu s standardom ISO 20079:2005. Klasično štetje stebelnih členkov smo nadgradili z uporabo metode računalniškega vida, pri kateri smo odčitavali površine stebelnih členkov pred in po sedemdnevni izpostavitvi vodnim vzorcem potoka Peklenščica. S tem smo odpravili napake, ki se lahko pojavijo pri štetju stebelnih členkov s prostim očesom. Spremembo v površini stebelnih členkov smo predstavili kot relativno stopnjo rasti (RGR) male vodne leče. Ugotovili smo zmanjšanje rasti po izpostavitvi vsem vodnim vzorcem potoka Peklenščica v primerjavi s kontrolo. Zmanjšanje rasti male vodne leče je eden od pokazateljev strupenosti vodnih vzorcev. Največje zmanjšanje rasti je bilo izračunano v vzorcih, odvzetih pri spomladanskem vzorčenju, najmanjše pa pri vzorcih, odvzetih v zimskem času. Izmed vseh merjenih parametrov (nitrati, nitriti, celotni fosfor in pH-vrednost) smo najvišjo stopnjo povezljivosti relativne stopnje rasti male vodne leče izračunali v povezavi s pH-vrednostmi vodnih vzorcev. Izsledki raziskave so pokazali, da je pH-vrednost odločilen limitirajoč faktor za rast male vodne leče. Pri nadaljnjih analizah bi bilo potrebno vzdrževati enake pH-vrednosti vodnih vzorcev, da bi lahko ugotovili vpliv drugih parametrov v vodi na rast male vodne leče.

Keywords

Lemna minor;test strupenosti;varstvo voda;Peklenščica;računalniški vid;magistrska dela;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UM FNM - Faculty of Natural Sciences and Mathematics
Publisher: [T. Krivec]
UDC: 582.532.4:581.5(043.2)
COBISS: 21140232 Link will open in a new window
Views: 1572
Downloads: 231
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Other data

Secondary language: English
Secondary title: ǂThe ǂresponse of common duckweed (Lemna minor L.) to the pollutants in the water samples of the Peklenščica stream
Secondary abstract: The purpose of this Master's Thesis was to determine the water quality of the Peklenščica stream with respect to the type of activities in the hinterland and different weather conditions. In doing so, we have expanded the basic physico-chemical analysis with a toxicity test using common duckweed (Lemna minor). Water samples were collected at five locations - from the source of the stream Peklenščica to the mouth of the creek Trnava within four samplings in total between November 2013 and August 2014. We performed the analysis of nitrate, nitrite and total phosphorus contents, and measured the pH-value in the laboratory. The highest concentrations of nutrients were detected in the spring sampling, which took place after heavy rains and the fertilization on the Ponikva plateau. The lowest values were detected in the winter sampling time with absence of both fertilization and rainfall on the plateau. The response of common duckweed to pollutants in water samples was evaluated by monitoring its growth in line with the standard ISO 20079: 2005. The established method of the counting of fronds was upgraded by computer vision, which calculated the surface of the fronds before and after the seven-day exposure to water samples of the Peklenščica stream. This eliminated errors that could occur by counting the fronds with the naked eye. Changes in the surface of the fronds were presented as relative growth rate (RGR). We found that there was a reduction of growth after the exposure to all water samples from the watercourse of the Peklenščica stream in comparison with the control. A reduction in the growth of the common duckweed is one of the indicators of the toxicity of water samples. The largest reduction of growth was calculated with the samples taken in the spring sampling, and the smallest with the samples collected in the winter. The highest level of coherency of the relative growth rate among all measured parameters (nitrates, nitrites, total phosphorus and pH-value) was calculated in conjunction with the pH- values of the water samples. The results of this study demonstrated that the pH-value is a limiting factor for the growth of the common duckweed. For further analysis the maintenance of pH-values in water samples would be necessary in order to determine the influence of other parameters in present in the water on the growth of the small common duckweed.
Secondary keywords: Lemna minor;toxicity test;water protection;Peklenščica;computer vision;master theses;
URN: URN:SI:UM:
Type (COBISS): Master's thesis/paper
Thesis comment: Univ. v Mariboru, Fak. za naravoslovje in matematiko, Oddelek za biologijo
Pages: VIII, 62 f.
ID: 8706940