20.500.12556/RUL-186494 Vpliv biorazgradljive mikroplastike na vodne organizme The effects of biodegradable microplastics on aquatic organisms Mikroplastika v vodno okolje vstopa v obliki majhnih plastičnih delcev ali kot posledica razgradnje in obrabe plastičnih materialov, ki se uporabljajo v vsakdanjem življenju. Zaradi okoljskih tveganj, povezanih z obstojnostjo plastike, se vse pogosteje raziskujejo biorazgradljive alternative, kot je polilaktična kislina (PLA) in poli(3-hidroksibutirat) (P3HB). Namen raziskave je primerjati in preučiti vpliv mikroplastike treh polimerov z različnimi stopnjami biorazgradljivosti, nerazgradljiv polietilen tereftalat (PET), slabo razgradljiv PLA in dobro razgradljiv P3HB na izbrana sladkovodna organizma Daphnia magna (vodna bolha) in Lemna minor (mala vodna leča). Da bi bolje posnemali okoljske razmere, smo organizma združili v sistem mikrokozmosa ter ju 21 dni izpostavili dvema koncentracijama mikroplastike (10 mg/L in 100 mg/L), pri čemer je bila velikost delcev manjša od 80 µm. Pri mali vodni leči smo spremljali vpliv na vsebnost klorofila a, dolžino korenin in na specifično hitrost rasti, pri vodnih bolhah pa reprodukcijo, preživetje ter morebitno akumulacijo delcev mikroplastike v organizmu. Najizrazitejši učinki so bili opaženi pri biorazgradljivi mikroplastiki P3HB. Pri nižji koncentraciji (10 mg/L) smo opazili stimulativen učinek na reprodukcijo vodnih bolh, medtem ko je pri višji koncentraciji (100 mg/L) prišlo do popolne nemobilnosti izpostavljenih organizmov. Pri vodni leči smo pri nižji koncentraciji (10 mg/L) opazili blag stimulativen učinek na rast, medtem ko smo pri višji koncentracijo opazili nasproten učinek. Pri PLA in PET izrazitih vplivov nismo zaznali pri nobeni od koncentracij, vendar so mikroskopske analize pokazale akumulacijo delcev mikroplastike v prebavilih vodnih bolh. Rezultati kažejo, da lahko mikroplastika vpliva na vodne organizme tako neposredno kot tudi posredno preko sprememb v okolju, pri čemer se odzivi organizmov razlikujejo glede na vrsto polimera, njegovih lastnosti in koncentracije. Raziskava poudarja pomen uporabe mikrokozmosov pri ocenjevanju okoljskih vplivov, saj omogočajo bolj realistično simulacijo dogajanja ob prisotnosti mikroplastike v okolju. Nadaljnje študije bi s preučevanjem dolgoročnih učinkov mikroplastike, posebno biorazgradljive, pomembno prispevale k razumevanju procesov razgradnje, bioloških odzivov in njihovega vpliva na sladkovodno okolje. Microplastics enter the aquatic environment in the form of smaller plastic particles or as a result of the degradation and processing of plastic materials used in everyday life. Due to environmental risks associated with the persistence of plastics, biodegradable alternatives such as polylactic acid (PLA) and poly(3-hydroxybutyrate) (P3HB) are increasingly being investigated. The aim of this study was to compare and examine the effects of microplastics from three polymers with different degrees of biodegradability: non-biodegradable polyethylene terephthalate (PET), poorly biodegradable PLA and readily biodegradable P3HB on the selected freshwater organisms Daphnia magna (water flea) and Lemna minor (duckweed). To better mimic environmental conditions, the organisms were combined in a microcosm system and exposed for 21 days to two concentrations of microplastics (10 mg/L and 100 mg/L), with the particle size being smaller than 80 µm. In the duckweed, we monitored the effect on chlorophyll a content, root length and specific growth rate, while in water flea we monitored reproduction, survival and potential accumulation of microplastics in the organism. The most pronounced effects were observed in the presence of biodegradable microplastics P3HB. At a lower concentration (10 mg/L), we observed a stimulatory effect on the reproduction of water flea, while at a higher concentration (100 mg/L) the exposed organisms were completely immobile. In duckweed, at a lower concentration (10 mg/L), we observed a mild stimulatory effect on growth, while at a higher concentration the opposite effect was observed. No pronounced effects were detected in presence of PLA and PET at both concentrations, but microscopic analyses showed the accumulation of microplastic particles in water flea. The results show that microplastics can affect aquatic organisms both directly and indirectly through changes in the environment, with the responses of organisms depending on the type of polymer, its properties and concentration. The research highlights the importance of using microcosms in assessing environmental impacts, as it requires a more realistic simulation of what happens when microplastics are present in the environment. Further studies examining the long-term effects of microplastics, especially biodegradable ones, would significantly contribute to understanding the degradation processes, biological responses and their impact on the freshwater environment. ekotoksičnost mikrokozmos mikroplastika sladkovodno okolje ecotoxicity freshwater microcosm microplastic true false false Slovenski jezik Angleški jezik Diplomsko delo/naloga 2026-09-02 12:15:25 2026-09-02 12:15:42 2026-09-17 10:09:48 0000-00-00 00:00:00 2026 0 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 25690 291390211 Kosak_Ursa_-_Vpliv_biorazgradljive_mikroplastike_na_vodne_organizme.pdf Kosak_Ursa_-_Vpliv_biorazgradljive_mikroplastike_na_vodne_organizme.pdf 1 905A11ADC71360626745527B096FBE61 b22b2e3881943dc3060c95ae64ab87cd5ad9c4680a6f8bce18aa60b99ee9a0ab dc8483b6-a6b6-11f1-9b0d-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=245761 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0