20.500.12556/RUL-185669 Adsorpcija metilensko modrega na kalcijev alginat/grafen oksid hidrogelnih delcih v pretočnem sistemu Adsorption of methylene blue onto calcium alginate/graphene oxide hydrogel particles in a flow system V diplomskem delu je bila preučena kontinuirna adsorpcija metilenskega modrega (MB) na kalcijev alginat/grafen oksid (Ca-Alg/GO) hidrogelnih kroglicah v koloni z nasutim slojem. Izvedenih je bilo šest meritev s sistematično variacijo pretoka (Q = 1, 3 in 5 mL/min), začetne koncentracije MB (C$_0$ = 2, 5 in 10 mg/L) in višine sloja (Z = 4,2 in 8,4 cm) pri stalnem notranjem premeru kolone (D = 9,6 mm) in premeru kroglic (d$_p$ = 2,405 mm). Koncentracija MB v iztočni raztopini je bila določena spektrofotometrično pri 665 nm z lastno umeritveno enačbo (naklon 0,2114 L/mg, R$^2$ = 0,9992). Iz eksperimentalnih prebojnih krivulj so bili z numerično integracijo izračunani masna bilanca, specifična kapaciteta, stehiometrični čas ter parametri cone prenosa snovi in kontaktni čas prazne posteljice. Eksperimentalni podatki so bili prilagojeni štirim empiričnim modelom: Thomasovemu, Yoon-Nelsonovemu, Yanovemu (dose-response) in difuzijskemu (erfc) modelu. Thomasov in Yoon-Nelsonov model sta bila numerično identificirana kot matematično ekvivalentna. Yanov model je pri vseh meritvah dosegel boljše statistično ujemanje (R$^2$ = 0,71-0,90) kot Thomasov model (R$^2$ = 0,30-0,71), ker pravilno napove ničelno iztočno koncentracijo na začetku eksperimenta. Brezdimenzijska analiza (Re, Sc, Sh, Bi) je ob privzeti vrednosti efektivnega difuzijskega koeficienta pokazala, da intrapartikularna difuzija skozi alginat/GO mrežo verjetno predstavlja korak, ki določa hitrost prenosa snovi (Bi ≫ 1). Dvostopenjski filmsko-difuzijski model je dosegel najvišje vrednosti R$^2$ (0,91–0,95), vendar je znotraj merjenega časovnega okna strukturno poddoločen, ker počasni intrapartikularni difuzijski režim deluje na bistveno daljši časovni skali kot trajanje posameznega eksperimenta. This thesis investigated the continuous adsorption of methylene blue (MB) onto calcium alginate/graphene oxide (Ca-Alg/GO) hydrogel beads in a packed bed column. Six experiments were carried out with systematic variation of flow rate (Q = 1, 3 and 5 mL/min), inlet MB concentration (C$_0$ = 2, 5 and 10 mg/L) and bed height (Z = 4.2 and 8.4 cm), at a constant column inner diameter (D = 9.6 mm) and bead diameter (d$_p$ = 2.405 mm). The MB concentration in the column effluent was determined spectrophotometrically at 665 nm using an experimentally derived calibration equation (slope 0.2114 L/mg, R$^2$ = 0.9992). Mass balance parameters including specific capacity, stoichiometric time, mass transfer zone length and empty bed contact time were calculated from the experimental breakthrough curves by numerical integration. The data were fitted to four empirical models: Thomas, Yoon-Nelson, Yan (dose-response) and the diffusion-based (erfc) model. The Thomas and Yoon-Nelson models were numerically confirmed to be mathematically equivalent. The Yan model consistently achieved better goodness of fit (R$^2$ = 0.71-0.90) than the Thomas model (R$^2$ = 0.30-0.71), as it correctly predicts zero effluent concentration at the start of the experiment. Dimensionless analysis (Re, Sc, Sh, Bi), based on an assumed effective diffusion coefficient, indicated that intraparticle diffusion through the alginate/GO network is likely the rate-limiting step (Bi ≫ 1). The two-stage film-diffusion model achieved the highest R$^2$ values (0.91–0.95) but was found to be structurally underdetermined within the experimental time window, as the slow intraparticle diffusion regime operates on a time scale significantly longer than the duration of individual experiments. adsorpcija metilensko modro alginat/grafen oksid nasuti sloj prebojne krivulje adsorption methylene blue alginate/graphene oxide packed bed column breakthrough curves true false false Slovenski jezik Angleški jezik Diplomsko delo/naloga 2026-08-17 12:50:04 2026-08-17 12:50:17 2026-08-28 09:06:28 0000-00-00 00:00:00 2026 0 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 25898 289210371 Kranjec_Klemen_-_Adsorpcija_metilensko_modrega_na_kalcijev_alginatgrafen_oksid_hidrogelnih_delc.pdf Kranjec_Klemen_-_Adsorpcija_metilensko_modrega_na_kalcijev_alginatgrafen_oksid_hidrogelnih_delc.pdf 1 9EEE93AAE9942414804DF44A40822E55 ca34fc78b8fdfbe33bc9de66bf1de99cfeb4b45b26c479ce2530b95f34995c6b 0ddf8119-9a29-11f1-9b0d-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=244432 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0