magistrsko delo
Primož Špringer (Author), Gabriela Kalčíková (Mentor), Marjan Marinšek (Thesis defence commission member), Gregor Marolt (Thesis defence commission member)

Abstract

Zaradi nepravilnega ravnanja z odpadki se količina plastičnih odpadkov v okolju znatno povečuje. Ti zaradi različnih okoljskih vplivov razpadajo na manjše delce, ki jih s skupnim izrazom imenujemo mikroplastika. Pri delu in raziskovanju mikroplastike v okolju se strokovnjaki spopadajo z raznimi težavami. Med njimi izstopa že sama detekcija in določitev vrste mikroplastike v okolju. Ker so se raziskave na tem področju razširile šele v zadnjih letih, je še vedno prisoten stalen razvoj novih, modernejših, cenovno ugodnejših in hitrejših metod za detekcijo. V magistrski nalogi smo se osredotočili na uporabo elektrokemijske metode za detekcijo mikroplastike, in sicer ciklično voltametrijo. Pri metodi s pomočjo elektrokemijske sonde (kalijev fericianid/ferocianid), električnega potenciostata in elektrode spodbujamo redoks reakcije in preverjamo spreminjanje toka v odvisnosti od napetosti. Za izvedbo eksperimentalnega dela smo uporabili t. i. sitotiskane (ang. Screen printed) elektrode, katerim smo predhodno modificirali površino z mezoporozno siliko ter prolinom. Uspešno modificirane elektrode smo nato izpostavili vzorcem s suspenzijo mikroplastike, suspenzijo bukovega prahu in slepim vzorcem. Ugotovili smo, da se je po izpostavitvi elektrode suspenziji mikroplastike le-ta vezala na delovno površino elektrode in zapolnila pore. S tem je mikroplastika prekinila oz. oslabila stik med elektrodo in elektrokemijsko sondo, zaradi česar je prišlo do zaviranja poteka redoks reakcij in posledično znižanja tokovnega odziva elektrode. Prav tako smo prišli do ugotovitve, da če elektrodo izpostavimo suspenziji bukovega prahu ali slepemu vzorcu ne pride do sprememb v tokovnem odzivu. Poleg kvalitativne analize pa smo raziskali tudi možnost kvantitativne. Tako smo modificirane elektrode izpostavili različnim koncentracijam suspenzij mikroplastike in prišli do rezultatov, ki nakazujejo na potencialno možnost uporabe elektrokemijske metode tudi za namen kvantitativne analize.

Keywords

mikroplastika;vodno okolje;sitotiskane elektrode;modifikacija elektrode;mezoporozna silika;ciklični voltamogrami;magistrska dela;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UL FKKT - Faculty of Chemistry and Chemical Technology
Publisher: [P. Špringer]
UDC: 504.5:678:543.552(043.2)
COBISS: 153396739 Link will open in a new window
Views: 63
Downloads: 12
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Other data

Secondary language: English
Secondary title: The use of cyclic voltammetry for detection of microplastics in aquatic samples
Secondary abstract: Due to improper waste management, the amount of plastic waste in the environment is increasing significantly. Because of the various environmental processes, these plastics disintegrate into smaller particles, collectively known as microplastics. Among them, the detection and determination of the type of microplastic present in the environment stands out. Research in this field has only expanded in recent years, therefore there is still a continuous development of new, innovative, more affordable, and faster methods for detection of microplastics. In the master’s thesis, we focused on the use of an electrochemical method, namely cyclic voltammetry. In the method, with the help of an electrochemical probe (potassium ferricyanide/ferrocyanide), an electric potentiostat and an electrode, we stimulate redox reactions and check the change of electric current depending on the voltage. To execute the experimental work, we used screen printed electrodes, the surface of which was previously modified with mesoporous silica and proline. Successfully modified electrodes were then exposed to samples with a suspension of microplastics, a suspension of beech dust and a blank sample. Results showed that microplastics bound to the working surface of the electrode and filled the pores. With this, microplastics interrupted or weakened the contact between the electrode and the electrochemical probe, therefore the course of redox reactions was inhibited and consequently the current response of the electrode decreased. We also concluded that if the electrode is exposed to a suspension of beech dust or a blank sample, there are no differences in the electric current response. In addition to qualitative analysis, we also investigated the possibility of quantitative analysis. Thus, we exposed the modified electrodes to different concentrations of microplastic suspensions and reached results that imply to the potential possibility of using the electrochemical method also for the purpose of quantitative analysis.
Secondary keywords: microplastic;cyclic voltammetry;screen-printed electrodes;electrode modification;mesoporous silica;Voltametrija;Univerzitetna in visokošolska dela;
Type (COBISS): Master's thesis/paper
Study programme: 1000376
Embargo end date (OpenAIRE): 1970-01-01
Thesis comment: Univ. v Ljubljani, Fak. za kemijo in kemijsko tehnologijo, smer Kemijsko inženirstvo
Pages: 55 str.
ID: 18841257