Title Ispitivanje kinetike i kapaciteta adsorpcije organskih onečišćivala na starene mikročestice polietilena Title (english) Investigation of adsorption kinetics and capacities of organic pollutants on weathered polyethylene microplastics Author Nikolina Perić Mentor Marin Kovačić (mentor)Committee member Marin Kovačić (predsjednik povjerenstva)Committee member Ana Lončarić Božić (član povjerenstva)Committee member Irena Ivanišević (član povjerenstva)Granter University of Zagreb Defense date and country 2022-09-29, Croatia Scientific / art field, TECHNICAL SCIENCES Abstract Polimeri su organske tvari velike molekulske mase, građeni su od mera odnosno manjih ponavljajućih jedinica vezanih kovalentnim vezama. Zbog različitih svojstava koje posjeduju polimeri imaju široku primjenu u različitim industrijama. Polietilen (PE) je jedan od najčešće korištena polimera. Termoplastičan je i lagan za obradu, fleksibilan, otporan je na niske temperature, vlačna naprezanja i abraziju, posjeduje nisku toplinsku vodljivost. Mikroplastika je pojam koji se najčešće odnosi na plastične čestice promjera manjeg od 5 mm, obzirom na izvor nastajanja mikroplastika se dijeli na dvije vrste primarnu i sekundarnu mikroplastiku. Razgradnjom plastike narušava se njena polimerna struktura te dolazi do promjene njenih fizikalnih, kemijskih i drugih svojstava. Starenje plastike, odnosno površinska razgradnja, je nepovratan proces pri kojim se mijenjaju karakteristična kemijska i fizikalna svojstva plastike. Industrija i poljoprivreda su uglavnom odgovorne za umjetna onečišćenja. Onečišćenje okoliša kategorički se dijeli na dvije vrste: organski i anorganski. Glavni uzročnici organskog onečišćenja su pesticidi, sintetičke boje i farmaceutici. Farmaceutici/lijekovi su tvari ili smjese različitih tvari koje se koriste za sprječavanje, ublažavanje i liječenje bolesti kod ljudi i životinja u određenim količinama i pri određenim uvjetima. Cilj ovog rada bio je ispitati kinetiku i kapacitet adsorpcije organskih onečišćivala, farmaceutika diklofenaka i ciprofloksacina na starene mikročestice polietilena. Korišten je polietilen visoke gustoće ne staren (HDPE 0) i staren 56 dana (HDPE UV 56) pod UV-zračenjem. Za određivanje promjene intenziteta karakterističnih pikova za navedene vrste mikroplastike provedeno je FTIR analiza. Promjena koncentracije ispitivanih farmaceutika praćena je visoko djelotvornom tekućinkom kromatografijom sa detektorom s nizom dioda. FTIR analiza je utvrdila karakteristične vrpce polietilena te se na dobivenom spektru može uvidjeti smanjenje intenziteta pikova za stareni uzorak što ukazuje na razgradnju mikroplastike. Korištenjem linerane regresije ovisnosti log (qe) o log (Ce) određena su vrijednosti koeficijenta korelacije (R^2) kojima se odredio Freundlich-ov model kao najpogodniji model za opis mehanizama adsorpcije. Dobivene vrijednosti koeficijenta n nalaze se između 1 i 2 što ukazuje na umjereno povoljan fizikalni proces.
Abstract (english) Polymers are organic substances with a large molecular weight, they are built from units or smaller repeating units connected by covalent bonds. Due to the different properties possessed by polymers, they are widely used in various industries. Polyethylene (PE) is one of the most commonly used polymers. It is thermoplastic and easy to process, flexible, resistant to low temperatures, tensile stresses and abrasion, and has low thermal conductivity. Microplastics is a term that most often refers to plastic particles with a diameter of less than 5 mm, depending on the source of formation, microplastics are divided into two types: primary and secondary microplastics. Degradation of plastic disrupts its polymer structure and changes its physical, chemical and other properties. Aging of plastic, or surface decomposition, is an irreversible process during which the characteristic chemical and physical properties of plastic change. Industry and agriculture are mainly responsible for man-made pollution. Environmental pollution is categorically divided into two types: organic and inorganic. The main causes of organic pollution are pesticides, synthetic dyes and pharmaceuticals. Pharmaceuticals/drugs are substances or mixtures of different substances that are used to prevent, alleviate and treat diseases in humans and animals in certain quantities and under certain conditions. The aim of this work was to examine the kinetics and adsorption capacity of organic pollutants, pharmaceuticals diclofenac and ciprofloxacin on aged polyethylene microparticles. High-density polyethylene, unaged (HDPE 0) and aged for 56 days (HDPE UV 56) under UV radiation, was used. FTIR analysis was performed to determine the change in the intensity of the characteristic peaks for the mentioned types of microplastics. The change in the concentration of the tested pharmaceuticals was monitored by high-performance liquid chromatography with a diode array detector. The FTIR analysis determined the characteristic bands of polyethylene, and the obtained spectrum shows a decrease in the intensity of the peaks for the aged sample, which indicates the degradation of microplastics. Using the linear regression of the dependence of log (qe) on log (Ce), the values of the correlation coefficient (R^2) were determined, which determined the Freundlich model as the most suitable model for the description of adsorption mechanisms. The obtained values of the coefficient n are between 1 and 2, which indicates a moderately favorable physical process.
Keywords
mikroplastika
polietilen
organska onečišćivala
farmaceutici
adsorpcija
Keywords (english)
microplastics
polyethylene
organic pollutants
pharmaceuticals
adsorption
Language croatian URN:NBN urn:nbn:hr:149:446598 Project Number: IP-2020-02-6033 Study programme Title: Applied Chemistry - Graduate study; specializations in: Environmental chemistry and green technologies, Advanced materials and technologies, Applied organic chemistry Type of resource Text File origin Born digital Access conditions Access restricted to students and staff of home institution Terms of use Created on 2023-03-29 08:18:01
