Funkcionalizirani magnetni nanodelci za odstranjevanje težkih kovin iz odpadnih vod

diplomsko delo univerzitetnega študijskega programa I. stopnje

Ana Jurgec (Author), Maja Leitgeb (Mentor), Katja Heržič (Co-mentor)

Abstract

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.

Keywords

težke kovine;krom(VI);odpadne vode;magnetni nanodelci;hitozan;diplomske naloge;

Data

Language:	Slovenian
Year of publishing:	2019
Typology:	2.11 - Undergraduate Thesis
Organization:	UM FKKT - Faculty of Chemistry and Chemical Engineering
Publisher:	[A. Jurgec]
UDC:	620.3:549.25:676.08(043.2)
COBISS:	22612502
Views:	841
Downloads:	110
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	English
Secondary title:	Functionalized magnetic nanoparticles for removal of heavy metals from wastewater
Secondary abstract:	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.
Secondary keywords:	heavy metals;chromium(VI);wastewater;magnetic nanoparticles;chitosan;
Type (COBISS):	Bachelor thesis/paper
Thesis comment:	Univ. v Mariboru, Fak. za kemijo in kemijsko tehnologijo
Pages:	VIII, 43 str.
ID:	11203690