Interactions of microplastics with aquatic plants and the possibility to use phytoremediation technologies for its removal from surface water

Mikroplastika sodi med kompleksne in razširjene polutante, zato njeno obnašanje v okolju težko napovemo. Namen te diplome je bil pregledati literaturo, ki opisuje interakcije mikroplastike z vodnimi rastlinami. Te interakcije so ključne z vidika razvoja fitoremediacijskih tehnologij za odstranjevanje mikroplastike iz vodnega okolja s pomočjo rastlin. Glavna problematika raziskav, ki preučujejo interakcije z vodnimi rastlinami, je ta, da obravnava interakcije mikroplastike le s posamezno rastlino. Celostnega oz. sistematičnega pregleda interakcij zaenkrat še ni. V diplomskem delu so interakcije predstavljene glede na porazdelitev mikroplastike po vodnem stolpcu – interakcije s plavajočimi rastlinami (Lemna minor, Salvinia cucullata) in s potopljenimi rastlinami (Myriophyllum spicatum L., Elodea sp. in Utricularia vulgaris). Zaznane interakcije pri teh rastlinah so elektrostatske – vodikove vezi med mikroplastiko in celulozno steno rastline. Pri mesojedi rastlini Utricularia vulgaris so bile za akumulacijo mikroplastike odgovorne njene pasti za lovljenje plena, kar nakazuje pomembnost rastlinske morfologije pri interakcijah z mikroplastiko. Na koncu diplomskega dela so predstavljene interakcije z morsko travo Thalassia testudinum in njena vloga pri prenosu mikroplastike med trofičnimi nivoji. Ugotovljeno je bilo, da se mikroplastika akumulira na listih in zaradi preraščanja z biofilmom ostane močno vezna na rastlini. Sposobnost vezave mikroplastike na rastline omogoča njeno odstranjevanje iz vodnega okolja (fitoremediacija).Microplastics are one of the most complex and ubiquitous pollutants, therefore, it is difficult to predict its behaviour in the environment. The aim of this diploma thesis was to review the literature describing the interactions of microplastics with aquatic plants. These interactions play an important role in the development of phytoremediation strategies for removal of microplastics from aquatic ecosystems. The main problem with research focused on interactions with aquatic plants is that they address interactions only with an individual plant. Systematic review of interactions is currently lacking. In this diploma thesis, the interactions are presented according to the distribution in the water column – floating plants (Lemna minor, Salvinia cucullata), submerged plants (Myriophyllum spicatum L., Elodea sp. and Utricularia vulgaris). Observed interactions in these plants were electrostatic – hydrogen bond between the microplastic and the cellulose wall of the plant. In the carnivorous plant Utricularia vulgaris, prey traps were responsible for accumulation of microplastics, suggesting the importance of plant morphology in study of interactions. Interactions of microplastics with seagrass Thalassia testudinum and its role in microplastic transfer between trophic levels are presented. It was found that microplastics accumulate microplastics on leaves through biofilms development. Therefore, plants have high potentials for phytoremediation due to strong interactions with microplastics