Učinak kratkotrajnog kontakta s alkoholima na performanse komercijalnih RO membrana

master's thesis

• Title (english): Effect of short-term contact with alcohols on the performances of commercial RO membranes
• Author: Ivana Komparić
• Mentor: Krešimir Košutić (mentor)
• Committee member: Krešimir Košutić (predsjednik povjerenstva)
• Committee member: Danijela Ašperger (član povjerenstva)
• Committee member: Lidija Furač (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2022-09-22, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering

Abstract

Membranske tehnologije pročišćavanja voda sve su atraktivnije za dobivanje pitke vode visoke kvalitete. S obzirom na sve veću potražnju za vodom uslijed porasta broja stanovništva i industrijalizacije te klimatskim promjenama, u posljednih deset godina, reverzna osmoza (RO) prevladavajuća je metoda desalinacije za dobivanje pitke vode iz mora i bočatih voda. Međutim, RO tehnologija suočava se s nedostacima poput relativno niskih flukseva vode koje imaju komercijalno dostupne membrane. Primjena postojećih visoko propusnih membrana nije opcija dobivanja većih količina voda jer one imaju nezadovoljavajuću selektivnost soli i ostalih komponenata. Stoga je membranska tehnologija trenutačno u potrazi za novim membranskim proizvodima, traženju novih materijala i načina priprave visokoproduktivnih, uz istrovremeno i visokoselektivnih membrana. Postoji nekoliko metoda za postizanje kompromisa između selektivnosti i propusnosti, a jedna od njih je aktivacija membranskog materijala otapalima. Ova je metoda učinkovita i ekonomski održiva te se sve više proučava i koristi za poboljšanje membranskih performansi. U ovome radu proučavan je utjecaj organskih otapala, točnije alkohola, na komercijalne tankoslojne kompozitne poliamdine (TFC-PA) RO membrame i njihove performanse. U laboratorijskom RO uređaju eksperimentalno su utvrđene promjene u protoku vode kroz membranu i faktoru zadržavanja NaCl i CaCl2, prije i nakon aktivacije membrana izabranim otapalima. Kratkotrajnim kontaktom aktivacijskog otapala i membrana od 5 i 60 minuta, postignuto je povećanje protoka vode uz zadržavanje vrijednosti faktora zadržavanja soli. Eksperimentalno je određen i utjecaj aktivacije na faktor zadržavanja N-nitrozamina, potencijalno kancerogenih spojeva koji nisu poželjni u vodama pa ih je potrebno ukloniti, za što se RO čini najpogodnijom metodom. Utvrđeno je minimalno 90%-tno zadržavanje odabranih N-nitrozamina.

Abstract (english)

Membrane technologies for water treatment are becoming increasingly attractive for obtaining high-quality drinking water. Considering the increasing demand for water due to population growth, industrialization and climate change, in the last decade, reverse osmosis (RO) has been the predominant desalination method for obtaining drinkable water from the sea and brackish waters. However, RO technology faces disadvantages such as relatively low water fluxes that commercially available membranes have. The use of existing highly permeable membranes is not an option for obtaining larger amounts of water because they have insufficient selectivity of salts and other components. Therefore, membrane technology is currently searching for new membrane products, new materials and ways of preparing highly productive, and at the same time, highly selective membranes. There are several ways to overcome the trade-off between selectivity and permeability, one of which is solvent activation of the membrane material. This method is efficient, economical and is increasingly being investigated and used to improve membrane performance. In this work, the influence of organic solvents, specifically alcohols, on commercial thin-film composite polyamide (TFC-PA) RO membranes and their performance is studied. Changes in the water flux through the membrane and the retention factor of NaCl and CaCl2 before and after the activation of the membranes with selected solvents were determined experimentally using a laboratory scale RO system. With short-term contact of the activation solvent and the membrane for 5 and 60 minutes, it was achieved an increase in water flux with no significant effect on the retention factor of inorganic salts. The influence of activation on the retention factor of N-nitrosamines, potentially carcinogenic compounds that are not welcome in water and therefore need to be removed, was determined experimentally, for which RO seems to be the most suitable method. A minimum of 90% retention of selected N-nitrosamines was determinded.

• Keywords: poliamidne tankoslojne kompozitne membrane; reverzna osmoza; alkoholi; protok vode; faktor zadržavanja; N-nitrozamini
• Keywords (english): polyamid thin-film composite membranes; reverse osmosis; alcohols; water flux; retention factor; N-nitrosamines
• Language: croatian
• URN:NBN: urn:nbn:hr:149:570922
• Study programme: Title: Materials Science and Engineering - Graduate study; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka kemijskog inženjerstva (magistar/magistra inženjer/inženjerka kemijskog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2023-03-23 10:29:55