Title Adsorpcija transformacijskog produkta antiozonanta iz automobilskih guma na mikroplastiku u vodi Title (english) Adsorption of the antiozonant by-product of from automobile tires on microplastics in water Author Martina Kujavić Mentor Hrvoje Kušić (mentor)Committee member Hrvoje Kušić (predsjednik povjerenstva)Committee member Ana Lončarić Božić (član povjerenstva)Committee member Dajana Kučić Grgić (član povjerenstva)Granter University of Zagreb Defense date and country 2023-09-20, Croatia Scientific / art field, TECHNICAL SCIENCES Abstract Antiozonanti dodaju se automobilskim gumama tijekom vulkanizacije, radi sprječavanja i usporavanja degradacije gume uzrokovane ozonom, čime se pruža zaštita i sigurnost vozača i putnika tijekom vožnje automobilom. 6PPD standardni je antiozonant u automobilskim gumama, ali kada reagira s ozonom nastaje njegov transformacijski produkt
N-(1,3-dimetilbutil)-N'-fenil-p-fenilendiamin-kinon (6PPD-Q). 6PPD kinon ispire se s automobilskih guma i cesta tijekom svakog hidrološkog ciklusa, što dovodi do njegove migracije u prirodne vode. Kada se nalazi u vodenome okolišu pokazuje toksičan utjecaj na razne ribice, račiće i mikroalge, ali uzrokuje i ugibanje određenih vrsta lososa. Mikroplastika pronalazi se u svakodnevno korištenim proizvodima, a zbog neadekvatnog zbrinjavanja njezinog otpada nakon uporabe, migrira u okoliš gdje također onečišćuje prirodne vode. Određeni vodeni organizmi, poput ribica i račića, neselektivno konzumiraju mikroplastiku što uzrokuje kratkotrajne i dugotrajne posljedice na njihov organizam. Budući da mikroplastika ima visoki stupanj adsorpcije, na površinu njezinih čestica mogu se adsorbirati organske onečišćujuće tvari iz okoliša. Adsorpcija je nagomilavanje (akumuliranje) čestica iz susjedne (plinovite ili kapljevite) faze na površinu krute faze, čemu je uzrok djelovanje privlačnih sila između čestica na krutoj površini i čestica iz susjedne faze. Testirana je adsorpcija 6PPD kinona u vodenoj otopini na mikroplastiku PP 0 (nestareni polipropilen) i PP UV 56
(UV stareni polipropilen). Uzorci su snimani na tekućinskom kromatografu visoke djelotvornosti (engl. High Performance Liquid Chromatography, HPLC) kojim je omogućeno određivanje koncentracije 6PPD kinona u vodenoj otopini prije i nakon adsorpcije. Također je testirana i toksičnost čistih otopina 6PPD kinona i mikroplastike te njihove mješavine 24 h nakon adsorpcije na slatkovodnim račićima Daphnia Magna. Rezultati su pokazali da adsorpcija 6PPD kinona na mikroplastiku u oba slučaja slijedi Langmuirov model, odvija se u monosloju te je raspodjela aktivnih mjesta na adsorbensu homogena. Starena mikroplastika (PP UV 56) ima veću adsorpcijsku ravnotežnu konstantu i samim time veći afinitet za adsorpciju 6PPD kinona, nego nestarena mikroplastika (PP 0). Također je ustanovljeno da je potrebna samo četvrtina uzorka čiste otopine 6PPD kinona da bi se postigla 50%-tna inhibicija račića Daphnia Magna. Iako je s usporedbom na navedenu otopinu potreban nešto veći udio uzorka vodene otopine 6PPD kinona s PP 0 i PP UV 56 24 h nakon adsorpcije, one i dalje pokazuju toksičan utjecaj na račiće.
Abstract (english) Antiozonants are added to car tires during vulcanization, in order to prevent and slow down the degradation of rubber caused by ozone, which enables the protection and safety of drivers and passengers while driving a car. 6PPD is a standard antiozonant in car tires, but when it reacts with ozone, its transformation by-product
N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine-quinone (6PPD-Q) is formed. 6PPD quinone is washed off of car tires and roads during each hydrologic cycle, leading to its migration into natural waters. When found in aquatic environment, 6PPD-Q shows a toxic effect on various fish, cryfish and microalgae, in addition it's deadly for certain types of salmon. Microplastics are found in everyday products, and due to inadequate disposal of their waste after use, they migrate into the environment where they also pollute natural waters. Certain aquatic organisms, such as fish and crayfish, indiscriminately consume it, which causes short-term and long-term consequences for their organisms. Since microplastics has a high value of adsorption capacity, organic pollutants from the environment can be adsorbed on the surface of its particles. Adsorption is accumulation of particles from a neighbouring (gas or liquid) phase on to the surface of the solid phase, which is caused by intermolecular forces of the particles on the solid surface and particles from the adjacant phase. Adsorption of 6PPD quinone in aqueous solution on microplastics PP 0 (unaged polypropylene) and PP UV 56 (UV aged polypropylene) was tested.
The samples were recorded with high performance liquid chromatography (HPLC), which enabled the determination of the concentration of 6PPD quinone in the aqueous solution before and after adsorption. The toxicity of blank solutions of 6PPD quinone and microplastics and their mixtures 24 h after adsorption on the freshwater flea Daphnia Magna was also tested. The results showed that the adsorption of 6PPD quinone on microplastics in both cases follows the Langmuir model, takes place in a monolayer, and the distribution of active sites on the adsorbent is homogeneous. Aged microplastic (PP UV 56) has a higher adsorption equilibrium constant and thus a higher affinity for 6PPD quinone adsorption than unaged microplastic (PP 0). Also, it was shown that only a quarter of a sample of blank 6PPD quinone solution is needed to achieve 50% inhibition of water flea Daphnia Magna. Although a slightly larger fraction of the sample of the aqueous solution of 6PPD quinone with PP 0 and PP UV 56 24 h after adsorption is required compared to the blank solution, they still show a toxic effect on water fleas.
Keywords
adsorpcija
6PPD kinon
mikroplastika
toksičnost
Keywords (english)
adsorption
6PPD quinone
microplastics
toxicity
Language croatian URN:NBN urn:nbn:hr:149:911612 Project Number: IP-2020-02-6033 Study programme Title: Materials Science and Engineering - Undergraduate study Type of resource Text File origin Born digital Access conditions Embargoed access Terms of use Created on 2023-11-29 11:50:50
