Title Ispitivanje interakcije pesticida i čestica mikroplastike u vodenom mediju Title (english) Investigation of interaction between pesticides and microplastic particles Author Iva Fereža Mentor Ana Lončarić Božić (mentor)Committee member Ana Lončarić Božić (predsjednik povjerenstva)Committee member Hrvoje Kušić (član povjerenstva)Committee member Ana Vrsalović Presečki (član povjerenstva)Granter University of Zagreb Defense date and country 2022-09-29, Croatia Scientific / art field, TECHNICAL SCIENCES Abstract Onečišćenje mora plastičnim otpadom jedan je od najhitnijih globalnih problema morskog okoliša u cijelom svijetu. Privukao je svjetsku pozornost vlada, javnosti, znanstvene zajednice, medija i nevladinih organizacija te je postao vruća tema u aktualnoj morskoj ekologiji i istraživanju okoliša. Cilj ovog rada bio je istražiti utjecaj temperature i starosti mikroplastike poli(etilen- tereftalata) (PET) na adsorpciju pesticida simazina (SMZ). Korištene su čestice mikroplastike (10-100 μm) pripremljene iz nestarenih filmova PET-a te filmova podvrgnutim ubrzanom starenju 56 dana pod UV zračenjem. Nakon usitnjavanja u kriomlinu određena je raspodjela veličina čestica mikroplastike, pri čemu su za razdvajanje frakcija korišteni vibrirajuća tresilica sa sitima i laboratorijsko sito sa zračnim mlazom. Adsorpcijski eksperimenti provedeni su korištenjem termostatirane laboratorijske tresilice, a promjene koncentracije simazina praćene su tekućinskom kromatografijom visoke djelotvornosti (HPLC). Na kraju su ispitani pojedinačni štetni učinci mikroplastike i simazina te ukupni učinci mikroplastike s adsorbiranim onečišćivalom, provedbom standardnih testova akutne toksičnosti na zelene mikroalge Pseudokirchneriella subcapitata (ISO 8692). Rezultati ATR-FTIR spektroskopijesu pokazali da se UV starenjem povećava udio manjih frakcija čestica mikroplastike, što znači da je zbog utjecaja starenja materijal više podložan fragmentaciji, te je došlo do oksidativne razgradnje koja rezultira stvaranjem funkcionalnih skupina koje sadrže kisik (smanjena hidrofobnost materijala). Rezultati adsorpcije simazina slijede Langmuirovom model što ukazuje na adsorpciju u monosloju te je raspodjela aktivnih mjesta na adsorbensu homogena. Adsorpcija je izraženija u slučaju starenih uzoraka u odnosu na uzorke mikroplastike koji nisu stareni, te je najveća adsorpcija simazina postignuta uz PET 56 pri temperaturi od 20°C. Ispitivanje toksičnosti na zelenim mikroalgama Pseudokirchneriella subcapitata pokazalo je najveću toksičnost kod kombiniranih uzoraka simazina sa starenom mikroplastikom (PET 56) i CaCl2.
Abstract (english) The pollution of the sea by plastic waste is one of the most urgent global problems of the marine environment all over the world. It has attracted worldwide attention from governments, the public, the scientific community, the media and non-governmental organizations and has become a hot topic in current marine ecology and environmental research. The aim of this work was to investigate the influence of temperature and age of poly(ethylene-terephthalate) (PET) microplastics on the adsorption of the pesticide simazine (SMZ). Microplastic particles (10-100 μm) prepared from pristine PET films and films subjected to accelerated aging were used 56 days under UV radiation were used. After grinding in a cryomill, the particle size distribution of microplastics was determined, using a vibrating shaker with sieves and a laboratory sieve with an air jet were used to separate the fractions. Adsorption experiments were carried out using a thermostated laboratory shaker, and changes in simazine concentration were monitored by high-performance liquid chromatography (HPLC). In the end, the individual harmful effects of microplastics and simazine and the overall effects of microplastics with adsorbed pollutant were tested by performing standard acute toxicity tests on the green microalgae Pseudokirchneriella subcapitata (ISO 8692). The results of ATR-FTIR spectroscopy showed that UV aging increases the proportion of smaller fractions of microplastic particles, which means that due to the influence of aging, the material is more susceptible to fragmentation, and oxidative decomposition has occurred, which results in the formation of functional groups containing oxygen (reduced hydrophobicity of the material). The results of simazine adsorption follow the Langmuir model, which indicates adsorption in a monolayer and the distribution of active sites on the adsorbent is homogeneous. Adsorption is more pronounced in the case of aged samples compared to pristine microplastic samples, and the highest simazine adsorption was achieved with PET 56 at a temperature of 20°C. The toxicity test on the green microalgae Pseudokirchneriella subcapitata showed the highest toxicity with the combined samples of simazine with aged microplastic (PET 56) and CaCl2.
Keywords
mikroplastika
simazin
adsorpcijski modeli
Pseudokirchneriella subcapitata
Keywords (english)
microplastics
simazine
adsorption models
Pseudokirchneriella subcapitata
Language croatian URN:NBN urn:nbn:hr:149:031307 Project Number: IP-2020-02-6033 Study programme Title: Chemical Engineering - Graduate study Type of resource Text File origin Born digital Access conditions Closed access Terms of use Created on 2023-03-29 09:50:15
