20.500.12556/DKUM-74201 Funkcionalizirani magnetni nanodelci za odstranjevanje težkih kovin iz odpadnih vod diplomsko delo univerzitetnega študijskega programa I. stopnje Functionalized magnetic nanoparticles for removal of heavy metals from wastewater Zagotavljanje čiste in kvalitetne vode postaja problem sodobne družbe. Težke kovine so eno izmed najnevarnejših onesnaževal, saj niso biološko razgradljive, se kopičijo v naravi in toksično učinkujejo na žive organizme že pri zelo nizkih koncentracijah. V primerjavi z ostalimi metodami za odstranjevanje težkih kovin iz odpadnih vod, se je adsorpcija na različne adsorbente izkazala kot bolj ekonomična in učinkovita. Z razvojem nanotehnologije so bili magnetni nanodelci deležni pozornosti mnogih raziskav za iskanje najprimernejši adsorbentov težkih kovin. Namen diplomske naloge je bila sinteza stabilnih maghemitnih nanodelcev ter njihova funkcionalizacija s hitozanom po treh različnih metodah. Ugotoviti je bilo treba, kateri delci so najprimernejši za odstranjevanje Cr(VI) ionov iz raztopine in pri kateri pH vrednosti je adsorpcija najučinkovitejša. Maghemitne delce smo sintetizirali z metodo koprecipitacije in jih nato funkcionalizirali s hitozanom po treh različnih metodah (metoda kovalentne vezave, mikroemulzijska metoda in suspenzijska zamreževalna metoda). Delce smo dodali v raztopino z znano koncentracijo Cr(VI) ionov, da je potekla adsorpcija. Adsorpcijo smo izvedli pri treh različnih pH vrednostih (pH 3, 4 in 5) ter določili optimalno vrednost za adsorpcijo težkih kovin na posamezne magnetne nanodelce. Kvantitativno analizo Cr(VI) v raztopini po adsorpciji smo izvedli spektrofotometrijsko z 1,5- difenilkarbazidom. Po opravljeni analizi smo primerjali uspešnost adsorpcije in določili delce, ki so dosegli najvišje odstotke adsorpcije. Ugotovili smo, da so najprimernejši delci za odstranjevanje Cr(VI) iz vode maghemitni delci funkcionalizirani z mikroemulzijsko metodo. Izkazalo se je tudi, da so najboljšo adsorpcijo vsi delci dosegli pri vrednosti pH 3. Providing clean and quality water is one of the major challenges of the modern world. Heavy metals are one of the most dangerous contaminants due to their non- degradability and persistence in the environment. Heavy metals accumulate through the food chain, moreover, they can be toxic and harmful to living organisms, even in small amounts of exposure. Among numerous technologies that have been developed for the removal of heavy metals from wastewater, adsorption has been proved as one of the most economical and efficient methods. As nanotechnology is progressing rapidly, magnetic nanoparticles have been gaining increasing interest as adsorbents for heavy metals. The aim of the diploma thesis was preparation of stable maghemite nanoparticles and their functionalization with chitosan, using three different methods. The main objectives were determining which magnetic nanoparticles are the most suitable for removal of Cr(VI) and evaluating removal efficiency at different pH. Maghemite nanoparticles were synthesized by co-precipitation method and then functionalized with chitosan by three different methods (covalent binding method, microemulsion method and suspension cross-linking technique). Different nanoparticles were used as magnetic adsorbents for removal of Cr(VI) from aqueous solution. In order to determine the effect of pH on the process od adsorption, we conducted experiments at different pH value (pH 3, 4, and 5). For quantitative determination of Cr(VI) concentrations in aqueous solutions after adsorption process, we used spectrophotometric method with 1,5-diphenylcarbazide. After analysis we ascertained which magnetic nanoparticles have achieved efficient removal rates of Cr(VI). The study reveals that the maghemite nanoparticles functionalized with chitosan by microemulsion method, are most effective adsorbents for removal of Cr(VI) from aqueous solutions. All off the tested maghemite nanoparticles achieved higher removal rates with a pH value decrease. težke kovine krom(VI) odpadne vode magnetni nanodelci hitozan heavy metals chromium(VI) wastewater magnetic nanoparticles chitosan true true false [A. Jurgec] Slovenski jezik Angleški jezik Diplomsko delo/naloga 2019-08-18 19:27:15 2019-09-11 17:39:39 2022-08-10 05:53:27 2019-09-27 03:11:34 2019 0 Maribor 0 Maribor VIII, 43 str. 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 620.3:549.25:676.08(043.2) 22612502 URN:SI:UM:DK:BE3MK6YZ UN_Jurgec_Ana_2019.pdf UN_Jurgec_Ana_2019.pdf 1 AB1354D86526976A03FA050B62541BB8 0a83ade8ca081781db4e434ecdc3e99f405ae2d67e7023857c985bf2a6689995 eda558ea-7c10-11eb-bb7a-00155d0001ca 20.500.12556/dkum/b8f59c27-0f2a-4d5a-bb73-f7df4a8973ee https://dk.um.si/Dokument.php?lang=slv&id=137516 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0