Napredni oksidacijski procesi kao predtretman biološkoj obradi voda onečišćenih polivinil kloridom

master's thesis

• Title (english): AOPs as a pre-step to biological treatment of PVC polluted waters
• Author: Lorena Valek
• Mentor: Šime Ukić (mentor)
• Committee member: Šime Ukić (predsjednik povjerenstva)
• Committee member: Dajana Kučić Grgić (član povjerenstva)
• Committee member: Matija Cvetnić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2022-09-13, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Chemistry

Abstract

Kontinuirana upotreba plastike u svakodnevnom životu dovodi do sve veće prisutnost plastičnog otpada u okolišu. Veliku zabrinutost predstavljaju čestice mikroplastike (MP) koje zbog svoje veličine i drugih svojstava mogu imati štetan utjecaj na brojne organizme i ukupni ekosustav. Izrazito negativan učinak mogu imati mikročestice poli(vinil-klorida) (PVC-a) jer tijekom njihove razgradnje dolazi do otpuštanja klorida u okoliš uz mogućnost nastajanja toksičnih međuprodukata. S obzirom da klasične metode obrade voda nisu dovoljno učinkovite za uklanjanje PVC mikroplastike iz vode, razmotrena je primjena naprednih oksidacijskih procesa (AOP). AOP-i se temelje na in situ stvaranju reaktivnih radikala koji mogu razgraditi organske onečišćujuće tvari. AOP tretman često nije ekonomski prihvatljiv; stoga se razmatra njihova upotreba u kombinaciji s biološkim procesima. U ovom radu ispitivana je učinkovitost UV-C/H2O2 i UV-C/S2O82– procesa u razgradnji mikročestica PVC-a veličine 25-100 μm. Cilj istraživanja bio je odrediti koji AOP će uzrokovati značajniju razgradnju PVC-a te odrediti optimalne uvjete njegovog provođenja. Karakterizacija MP-a provedena je FTIR spektroskopijom, a za vodeni medij provodile su se TOC i LC-MS analize. Iz dobivenih rezultata vidljivo je kako primijenjeni AOP-i ne uzrokuju potpunu mineralizaciju ispitivane mikroplastike. Veća fragmentacija PVC-a primijećena je nakon obrade UV-C/S2O82– procesom; samim time je zaključeno da je on kvalitetniji izbor kao predtretman biološkoj obradi voda onečišćenih mikročesticama PVC-a. Učinkovitost razgradnje ovisi, naravno, o vremenu razgradnje, koncentraciji oksidansa i pH medija. UV-C/S2O82– proces ima potencijal povećati biorazgradivost PVC-a. Kombinacija ovih dvaju procesa doprinos je ideji zelene kemije.

Abstract (english)

Due to the constant use of plastics in daily life, plastic waste in the environment is becoming more and more common. Particles of microplastics (MP) are of major concern due to their size and some other properties. They have various adverse effects on organisms and the entire ecosystem. Poly(vinyl-chloride) (PVC) microparticles have particularly adverse effects because their degradation releases chlorides into the environment, which can form various toxic substances. Conventional water treatment methods are not efficient enough to remove MP PVC from polluted waters, so the application of advanced removal technologies has been considered. Advanced oxidation processes (AOPs) are processes based on the in situ formation of highly reactive radicals capable of degrading organic pollutants from aqueous media. AOPs are not economically feasible, so a combination of AOPs and biological processes is being considered as a treatment approach. In this study, the degradation of PVC particles with size between 25 and 100 μm by UV-C/H2O2 and UV-C/S2O82– processes was tested. The objective was to determine which of the tested AOPs caused more degradation of MP PVC and which conditions were optimal. The PVC microparticles were characterized by FTIR analysis and the aqueous medium was analyzed by TOC and MS. According to the research results, it was found that both AOPs did not cause complete mineralization of MP PVC under the applied conditions. More fragmentation of MP PVC was observed after UV-C/S2O82– treatment. Moreover, it is considered that the UV-C/S2O82– process is the better choice as a pretreatment for biological processes of waters contaminated with PVC microparticles. Of course, the degradation efficiency depends on the applied degradation time, oxidant concentration and pH. The UV-C/S2O82- process has the potential to increase the biodegradability of PVC. The combination of these two processes is a contribution to the development of sustainable water treatment technologies that are in line with the idea of green chemistry.

• Keywords: napredni oksidacijski procesi; poli(vinil-klorid); UV-C/H2O2 proces; UV-C/S2O82– proces; biorazgradnja
• Keywords (english): advanced oxidation process; poly(vinyl-chloride); UV-C/H2O2 process; UV-C/S2O82– process; biodegradation
• Language: croatian
• URN:NBN: urn:nbn:hr:149:991423
• Project: Number: IP-2019-04-9661; Title: Primjena naprednih tehnologija obrade voda za uklanjanje mikroplastike; Title: Advanced Water Treatment Technologies for Microplastics Removal; Acronym: AdWaTMiR; Leader: Tomislav Bolanča; Jurisdiction: Croatia; Funder: HRZZ; Funding stream: IP
• Study programme: Title: Applied Chemistry - Graduate study; specializations in: Environmental chemistry and green technologies, Advanced materials and technologies, Applied organic chemistry; Course: Environmental chemistry and green technologies; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra primijenjene kemije (magistar/magistra primijenjene kemije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2023-03-19 17:30:33