Title Reduktivne metode za razgradnju perfluoriranih spojeva u vodama Title (english) Reduction methods for degradation of perfluorinated compounds in water Author Nikolina Karačić Mentor Hrvoje Kušić (mentor)Committee member Hrvoje Kušić (predsjednik povjerenstva)Committee member Josipa Papac Zjačić (član povjerenstva)Committee member Matija Cvetnić (član povjerenstva)Granter University of Zagreb Defense date and country 2024-09-19, Croatia Scientific / art field, TECHNICAL SCIENCES Abstract Perfluorirani spojevi (engl. Perfluoroalkyl substances, PFAS) koriste se kao aditivi u raznim proizvodima, poput posuđa s neprijanjajućim slojem, vodootpornog materijala, ambalaže za hranu, kao pjena za gašenje požara, zbog njihove stabilnosti i otpornosti na masnoću, vodu i toplinu. Prilikom upotrebe tih proizvoda, a posebno prilikom njihovog neadekvatnog odlaganja u okoliš, može doći do onečišćenja tla, a posljedično i voda. Kada dospiju u okoliš, dolazi do bioakumulacije PFAS-a, pri čemu mogu imati negativno djelovanje na fluoru i faunu, te posljedično, na ljudsko zdravlje; zbog čega često nose naziv "vječne kemikalije". Europska regulativa prepoznala je ovu opasnost i ustanovila maksimalno dozvoljenu koncentracija PFAS spojeva u vodi za piće 0,5 μg/L, stoga ih je važno ukloniti iz otpadnih voda, odnosno razgraditi. Konvencionalni sustavi za obradu otpadnih voda nisu dovoljno učinkoviti za tu svrhu. S druge strane, napredne metode uključuju membrane koje nisu učinkovite za razgradnju već uklanjanje PFAS-a; za razliku od njih napredni oksidacijski procesi djelomično su učinkoviti za razgradnju PFAS spojeva pomoću hidroksilnih radikala; ipak, krajnji je cilj postizanje defluorizacije PFAS spojeva, što je moguće postići reduktivnim procesima.
Cilj je ovog rada dati literaturni pregled postojećih reduktivnih naprednih metoda ARP (engl. Advanced Reduction Process, ARP) za razgradnju PFAS spojeva. Pritom se ARP odvija pomoću fotogeneriranih elektrona, odnosno superoksidnih radikala. U slučaju fotokatalitičke reduktivne razgradnje PFAS spojeva nastaju razgradni produkti jednostavnije strukture, pri čemu su korišteni mehanizmi H/F supstitucije i skraćivanje alifatskog lanca, što podrazumijeva kidanje C-F veze. Elektrokemijska razgradnja podrazumijeva razgradnju PFAS spojeve do odgovarajućeg stupnja mineralizacije, no pri tome nastaje nusprodukt HF čiju je emisiju potrebno kontrolirati. Termička reduktivna metoda podrazumijeva korištenje visokih reduktivnih temperatura prilikom razgradnje PFAS spojeva, gdje je također potrebno obratiti pozornost na emisiju HF.
Abstract (english) Perfluorinated substances (PFAS) are being used as additives in various products, such as cookware with a non-stick layer, waterproof material, food packaging and as firefighting foam due to their stability and resistance to grease, water and heat. During the use of these products, especially during their inadequate disposal in the environment, both soil and water pollution may occur. When they reach the environment, bioaccumulation of PFAS occurs, whereby they may not only have a negative effect on fluorine and fauna but also on human health. Therefore, they are often called "eternal chemicals". European regulations recognized this danger and established the maximum allowed concentration of PFAS compounds in drinking water of 0.5 μg/L, therefore it is important to remove them from wastewaters, which means to decompose them. Conventional wastewater treatment systems are not efficient enough for this purpose. On the other hand, advanced methods include membranes that are not effective for degradation but removal of PFAS. Unlike the latter, advanced oxidation processes are partially effective for the degradation of PFAS compounds using hydroxyl radicals. Nevertheless, utter gaol is to achieve defluorination of PFAS compounds, which can be achieved by reductive processes. The aim of this paper is to give a literature review of the existing reductive advanced methods (ARP) for the degradation of PFAS compounds. Thereat, ARP takes place with the help of photogenerated electrons, that is superoxide radicals. In the case of photocatalytic reductive decomposition of PFAS compounds, decomposition products of a simpler structure are formed, whereby the mechanisms of H/F substitution and shortening of the aliphatic chain, which implies breaking the C-F bond, are used. Electrochemical decomposition implies the decomposition of PFAS compounds to the appropriate degree of mineralization, but in doing so, the byproduct HF is formed and its emission must be controlled. The thermal reductive method implies the use of high reductive temperatures during the decomposition of PFAS compounds, where it is also necessary to pay attention to the emission of HF.
Keywords
perfluorirani spojevi
onečišćenje
obrada vode
napredne reduktivne metode
Keywords (english)
perfluorinated compounds
pollution
water treatment
advanced reductive methods
Language croatian URN:NBN urn:nbn:hr:149:177811 Project Number: IPS-2022-02-4780 Study programme Title: Environmental Engineering - Undergraduate study Type of resource Text File origin Born digital Access conditions Embargoed access Terms of use Created on 2024-11-16 23:11:35
