NF/RO treatment of municipal wastewater

Potreba za pitkom, industrijskom i vodom za navodnjavanje svakim danom raste dok se ukupne zalihe dostupne vode smanjuju. Ta činjenica danas je prepoznata u svijetu te se traže novi i unaprjeđuju postojeći načini pripreme i obrade voda za korištenje. Jedan od njih je oporaba komunalne otpadne vode (KOV). Postoji više klasičnih metoda njezine oporabe, međutim sve više se nameću napredne membranske tehnologije mikrofiltracije (MF), ultrafiltracije (UF), nanofiltracije (NF) i reverzne osmoze (RO) te one u oporabi KOV-a dobivaju sve veću ulogu. Korištenjem tih tehnologija obrađena voda ispunjava najstrože standarde i kao takva može se koristiti u industriji i poljoprivredi. Svrha ovog rada bilo je istražiti koje su prednosti i mane korištenja NF/RO tehnologija u oporabi KOV-a te koji je potencijal njihovog korištenja. Utvrđeno je da postoji dosta prednosti u korištenju membranskih tehnologija: spadaju u ekološki održive tehnologije, mogu učinkovitije ukloniti tvari koje se drugim metodama ne mogu (nova onečišćavala, pesticidi), automatizam, zauzimaju malo prostora te mnoge druge. Glavni nedostatak je u troškovima rada, a njih najviše povisuje fenomen blokiranja membrana. To je detaljno ispitivano u eksperimentalnom dijelu ovog rada te je utvrđeno da blokiranje negativno djeluje na kvalitativna i kvantitativna svojstva obrađene vode. Prema tome, kako bi se otvorila još veća mogućnost korištenja NF/RO tehnologija potrebno je daljnje istraživanje fenomena blokiranja te posebice na koji način ga smanjiti. U radu su dani primjeri postrojenja koji na efikasan način smanjuju fenomen blokiranja membrana. To se postiže korištenjem hibridnih membranskih tehnologija gdje se uz odgovarajuću predobradu smanjuje blokiranje NF/RO membrana.The need for potable, industrial and irrigation water increases every day, while the total amount of avaliable water reduces. That fact is well recognized in the world today, and thats why new ways are being found and current ones are being upgraded for preparing and treating water for usage. One of them is recovery of municipal wastewater (MW). There are few common methods for it, however advanced membrane technology of microfiltration (MF), ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO) are increasingly being imposed and their role in recovery of MW is increasing. Using thoese technologies processed water meets highest standards and as that it can be used in industry and agriculture Purpose of this work was to investigate advantages and disadvantages of using NF/RO technologies in municipal wastewater recovery, and what is the potential of their usage. It was found that there are a lot of advatanges: they are green technologies, they can remove substances that cant be removed with other methods (new pollutants, pesticides), automatism, they take little space and many more. Main disadvantage is cost of work and it is mostly increased by membrane fouling. It was investigated in experimental part of this work and it was established that it has negative influence on qualitative and quantitative characteristics of treated water. Because of that there is need for continuation in research of membrane fouling, and especially how to reduce it, so NF/RO can be used even more. In this work few examples of treatmant plants which deal efficiently with membrane fouling have been given. That is achieved using hybrid membrane technologies in which adequate pretreatment lowers fouling of NF/RO membranes