Študija učinkovitosti adsorpcije težkih kovin na funkcionalizirane magnetne nanostrukture

diplomsko delo univerzitetnega študijskega programa I. stopnje

Nika Caf (Author), Mateja Primožič (Mentor), Maja Leitgeb (Co-mentor), Katja Heržič (Co-mentor)

Abstract

Dandanes je kontaminacija vod s težkimi kovinami vedno resnejši problem prav zaradi njihovih negativnih učinkov na pitno vodo ter ekosistem. Težke kovine že v majhnih koncentracijah resno ogrožajo zdravje ljudi, živali in naravo. Gre za svetovni problem in pri njegovi sanaciji se uporabljajo različne separacijske metode, med njimi tudi adsorpcija na različne materiale s pomočjo zunanjega magnetnega polja. V okviru diplomske naloge smo izvedli študijo adsorpcije Cr(VI) iz vodne raztopine z uporabo visoko funkcionaliziranih magnetnih nanostruktur. Za intenziviranje adsorpcije smo uporabili reaktor z izmenjujočim zunanjim magnetnim poljem. Proučevali smo vpliv različnih parametrov (čas adsorpcije, frekvenco magnetnega polja, masa adsorbenta, začetna koncentracija adsorbata) na učinkovitost odstranjevanja Cr(VI) iz vodne raztopine. Kot adsorbent smo sintetizirali magnetne nanodelce, prevlečene s polisaharidom arabinogalaktanom po dveh različnih postopkih. Pri prvem sinteznem postopku se je polisaharidna prevleka arabinogalaktana adsorbirala na magnetne nanodelce, pri drugem sinteznem postopku pa smo uporabili zamreževalno tehniko z uporabo zamreževalca glutaraldehida. Po izvedbi adsorpcije smo naredili tudi kvantitativno analizo odstranitve Cr(VI), kjer smo uporabili ortofosforno raztopino in 1,5-difenilkarbazid kot reagenta za UV-VIS spektrofotometrično analizo. Rezultati so pokazali, da so bili oboji delci zelo učinkoviti pri odstranjevanju Cr(VI) iz vodne raztopine. Delež adsorpcije Cr(VI) je bil pri obeh magnetnih delcih zelo visok ̴ 100 %. Delci, ki so bili funkcionalizirani z adsorpcijo imajo močnejše adsorpcijske vezi, višjo intenzivnost adsorpcije in višjo adsorpcijsko zmogljivost primerjavi z delci, ki so bili funkcionalizirani z zamreževalno tehniko.

Keywords

težke kovine;magnetni nanodelci;krom;adsorpcija;arabinogalaktan;odpadne vode;diplomske naloge;

Data

Language:	Slovenian
Year of publishing:	2022
Typology:	2.11 - Undergraduate Thesis
Organization:	UM FKKT - Faculty of Chemistry and Chemical Engineering
Publisher:	[N. Caf]
UDC:	66.081.3:546.766(043.2)
COBISS:	130572547
Views:	97
Downloads:	15
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	English
Secondary title:	Study of heavy metals adsorption efficiency on functionalized magnetic nanostructures
Secondary abstract:	Nowadays, contamination of water with heavy metals is an increasingly serious problem, because of their negative effects on drinking water and the ecosystem. Even at low concentrations, heavy metals pose a serious threat to human, animal and environmental health. The problem is global and various separation methods are used to remediate it, including adsorption on different materials using an external magnetic field. In the framework of the thesis, a study on the adsorption of Cr(VI) from aqueous solution using highly functionalised magnetic nanostructures in an alternating magnetic field reactor was carried out. The influence of different parameters (adsorption time, magnetic field frequency, particle mass) on the removal efficiency of Cr(VI) from aqueous solution was investigated. Magnetic nanoparticles coated with the polysaccharide arabinogalactan were synthesised as adsorbent by two procedures. In the first synthesis procedure, the polysaccharide coating of arabinogalactan was adsorbed onto the magnetic nanoparticles, while in the second synthesis procedure, a crosslinking technique using a glutaraldehyde crosslinker was applied. After adsorption, a quantitative Cr(VI) removal analysis was also performed using orthophosphoric solution and 1,5-diphenylcarbazide as reagents for UV-VIS spectrophotometric analysis. The results showed that both particles were very effective in removing Cr(VI) from aqueous solution. The Cr(VI) adsorption fraction was very high for both magnetic particles ̴ 100%. When using functionalised magnetic nanostructures coated with arabinogalactan by adsorption, the results showed that the following parameters are most effective for adsorption of Cr(VI) from aqueous solution: 1 mg/L of initial adsorbate solution, 30 mg of adsorbent magnetic particles and 600 mHz of magnetic field frequency. However, when Cr(VI) was removed from aqueous solution using functionalised arabinogalactan-coated magnetic nanostructures by the crosslinking technique, the optimum electric current frequency was 100 mHz, the mass of the adsorbent particles was 50 mg and the initial concentration of the K2Cr2O7 solution was 1 mg/L. The particles functionalized by adsorption have stronger adsorption bonds, higher adsorption intensity and higher adsorption capacity compared to the particles functionalized by the crosslinking technique.
Secondary keywords:	heavy metals;magnetic nanoparticles;chromium;adsorption;arabinogalactan;wastewater;
Type (COBISS):	Bachelor thesis/paper
Thesis comment:	Univ. v Mariboru, Fak. za kemijo in kemijsko tehnologijo
Pages:	1 spletni vir (1 datoteka PDF (X, 42 f.))
ID:	16273474