Naslov (srp)

Modifikacija, karakterizacija i primena adsorbenata na bazi gljive Handkea utriformis za uklanjanje jona metala iz vode : doktorska disertacija

Autor

Milošević, Dragana L., 1986-

Doprinosi

Petrović, Predrag M., 1987-
Petrović, Rada, 1965-
Marinković, Aleksandar D., 1970-
Milivojević, Milan, 1971-
Veličković, Zlate, 1967-

Opis (eng)

The aim of this study was to investigate the influence of modification of alkali–activatedsubgleba of the mosaic puffball mushroom (Handkea utriformis) using alumina and hydroxyapatite(HAp) on the adsorption of Pb2+, Cd2+ and Ni2+ ions on the obtained materials compared toadsorption on starting materials. These materials were chosen because of their non–toxicity, lowcost, chemical and thermal stability, insolubility in water, as well as possibility of obtaining fromnatural sources and waste.Previous research showed that γ–alumina (γ–Al2O3) and HAp, in different forms, have anaffinity for the adsorption of metal ions from aqueous solutions. However, a great tendency towardsagglomeration of very fine particles leads to the formation of aggregates, reducing the areaavailable for adsorption and thus their adsorption capacity. To prevent the formation of aggregatesand increase the adsorption capacity, alkali–activated subgleba was used as a substrate fordeposition of HAp and material based on γ–Al2O3.The porosity and number of surface functional groups (amino and hydroxyl) of the subgleba(Su) are increased by alkaline activation (Sa). Chemical analysis of subgleba confirmed thepresence of polysaccharides and proteins, i.e. functional groups suitable for adsorption of metalcations from water, but also for further modification to obtain materials with better adsorptionproperties.The improvement of the adsorption properties of alumina was achieved by the synthesis ofthree–dimensionally ordered macroporous (3DOM) alumina doped with iron (III)–oxide, (Al,Fe)2O3, and subsequently surface modified with amino silane (Al,Fe)2O3APTES. Amino groupsintroduced by surface modification had an additional impact on improving the adsorption propertiesaccording to the tested cations, but also achieved the possibility of covalent binding to the alkali–activated surface of the subgleba via 3–(carbomethoxy)propanoyl chloride (CPC), (SaCPC–(Al,Fe)2O3APTES). The synthesis of 3DOM (Al,Fe)2O3 was achieved using a colloidal crystaltemplate – poly(methylmethacrylate) and this method was appropriate to obtain a macroporousmaterial with a high adsorption capacity toward metal ions, while the role of spherical particles ofpoly(methylmethacrylate) was crucial for the formation of macropores.Alkali treated subglebal material (Sa) was used as a substrate for the deposition ofhydroxyapatite by the successive ionic layer adsorption and reaction (SILAR) method that achieveda controlled crystals growth rate. A relatively uniform and homogeneous HAp film, composed ofaggregated fine particles, was formed on the substrate surface in 15, 25 or 30 cycles by immersingin each precursor for 5 s and rinsing with water between cycles, providing a rough surface andporous structure. Since the amount of deposited apatite increased with the increasing number ofcycles, for further characterization, kinetics and adsorption/desorption tests, Sa–HAp synthesized in25 cycles was used as the most optimal.The morphology of the starting and synthesized materials was examined using scanningelectron microscopy (SEM), textural properties by nitrogen adsorption/desorption isotherms at thetemperature of liquid nitrogen (BET method), chemical composition was determined using theenergy dispersive spectroscopy (EDS), types of bonds were determined using Fourier–transforminfrared spectroscopy (FTIR). The point of zero charge was determined using the pH drift method.The kinetic study of ion adsorption of all tested materials showed that pseudo–second orderwas the model that best described the experimental adsorption data compared to pseudo first andfirst order models, indicating the formation of chemical interactions between adsorbates and freesites on the adsorbent surface. The Weber–Morris kinetic model showed that the rate of adsorptionis determined by both intraparticle diffusion and boundary layer diffusion.The adsorption process of Su, Sa and Sa–HAp was better described by the Langmuir model,indicating that monolayer adsorption occurs. The adsorption capacities of Sa–HAp, at all examinedtemperatures, were higher than the adsorption capacities of Sa and Su. It is assumed that thedeposition of HAp on Sa led to an increased number of hydroxyl groups, which in addition to theexisting amino groups in Sa, introduced due to alkaline treatment, provided the higher adsorptioncapacity of Sa–HAp compared to Sa and Su.The adsorption on (Al,Fe)2O3, (Al,Fe)2O3APTES and SaCPC–(Al,Fe)2O3APTES was betterdescribed by the Freundlich model, i.e. adsorption is multilayered with heterogeneous distributionof active sites on the material surface. The adsorption capacities of SaCPC–(Al,Fe)2O3APTES, at allexamined temperatures, were higher than the adsorption capacities of Sa and (Al,Fe)2O3APTES.Although surface modification with amino silane ((Al,Fe)2O3APTES) did not increase specificsurface area compared to structurally modified material (Al,Fe)2O3, higher adsorption capacities ofamino–functionalized material are a consequence of surface functionality.The capacities of the hybrid materials SaCPC–(Al,Fe)2O3APTES and Sa–HAp for Pb2+,Cd2+ and Ni2+, at the initial pH = 6 or 6.5, are higher than the capacities of the starting materials(Su, Sa, (Al,Fe)2O3 and (Al,Fe)2O3APTES) due to lower degree of agglomeration and thus greatersurface availability. For all ions and tested materials, the increase in temperature leads to anincrease in the adsorption capacity, which indicates that the adsorption process is endothermic.

Opis (srp)

Predmet istraņivanja ove doktorske disertacije je modifikacija alkalno aktiviranogsubglebalnog tkiva gljive Handkea utriformis aluminijum–oksidom i hidroksiapatitom (HAp) iispitivanje adsorpcije jona Pb2+, Cd2+ i Ni2+ na dobijenim materijalima u poreĊenju sa adsorpcijomna polaznim materijalima. Navedeni materijali su izabrani zbog netoksiĉnosti, niske cene, hemijskei termiĉke stabilnosti, kao i mogućnosti dobijanja iz prirodnih izvora i otpada.Dosadańnja istraņivanja su potvrdila da γ–aluminijum–oksid (γ–Al2O3) i HAp, u razliĉitimoblicima, imaju afinitet za adsorpciju jona metala iz vodenih rastvora i da se kapacitet adsorpcijepovećava sa smanjenjem veliĉine ĉestica. MeĊutim, velika sklonost ka aglomeraciji veoma finihĉestica dovodi do stvaranja agregata, ńto smanjuje povrńinu dostupnu za adsorpciju, pa samim tim injihove adsorpcione sposobnosti. Sa ciljem da se spreĉi stvaranje agregata i poveća adsorpcionikapacitet, tkivo alkalno aktivirane subglebe gljive Handkea utriformis je korińćeno kao nosaĉ zaHAp i materijale na bazi γ–Al2O3.Poroznost i broj povrńinskih funkcionalnih grupa (amino i hidroksilnih) subglebe (Su) jepovećan alkalnom aktivacijom (Sa). Hemijska analiza subglebe je potvrdila prisustvo polisaharida iproteina, odnosno funkcionalnih grupa pogodnih za adsorpciju katjona metala iz vode, ali i za daljumodifikaciju u cilju dobijanja materijala sa boljim adsorpcionim svojstvima.Poboljńanje adsorpcionih svojstava aluminijum–oksida je ostvareno sintezomtrodimenzionalnog makroporoznog (3DOM) γ–aluminijum–oksida strukturno modifikovanoggvoņĊe(III)–oksidom, (Al,Fe)2O3, a zatim i povrńinski aminosilanom, (Al,Fe)2O3APTES.Povrńinskom modifikacijom su uvedene amino funkcionalne grupe, ĉime je izvrńen dodatan uticajna poboljńanje adsorpcionih svojstava prema ispitivanim katjonima, ali i ostvarena mogućnostkovalentnog vezivanja na alkalno aktiviranu povrńinu subglebe preko 3–(karbometoksi) propanoilhlorida (CPC), (SaCPC–(Al,Fe)2O3APTES). Sinteza 3DOM (Al,Fe)2O3 je ostvarena korińćenjemkoloidnog kristalnog ńablona – poli(metil metakrilata), i pokazala se pogodnom za dobijanjematerijala koji je makroporozan, velikog kapaciteta adsorpcije prema jonima metala, pri ĉemu jeuloga sfernih ĉestica poli(metil metakrilata) bila kljuĉna za formiranje makro–pora.Hidroksiapatit je deponovan na Sa, metodom naizmeniĉne jonske adsorpcije i reakcije(SILAR metoda), kojom je postignuta kontrolisana brzina rasta kristala. Nanońenjm apatita u 15, 25ili 30 ciklusa po 5 s natapanja u svakom prekursoru, sa ispiranjem vodom izmeĊu ciklusa, formiranje relativno uniforman i homogen HAp film na povrńini nosaĉa, sastavljen od agregata finih ĉestica,ńto je rezultiralo hrapavom povrńinom i poroznom strukturom. Povećanjem broja ciklusa koliĉinadeponovanog apatita se povećavala, pa je za dalju karakterizaciju, ispitivanja kinetike iadsorpcije/desorpcije, kao najoptimalniji korińćen Sa–HAp sintetisan u 25 ciklusa.Morfologija polaznih i sintetisanih materijala ispitana je skenirajućom elektronskommikroskopijom (SEM), teksturalna svojstva adsorpcijom azota na temperaturi teĉnog azota (BETmetoda), hemijski sastav energetskom disperzionom spektroskopijom (EDS), a vrste vezainfracrvenom spektroskopijom sa Furijeovom transformacijom (FTIR). Taĉka nultog naelektrisanjaje odreĊena uravnoteņavanjem posebnih proba.Kinetika adsorpcije jona na svim ispitivanim materijalima se bolje opisuje modelompseudo–drugog reda nego modelima pseudo–prvog i prvog reda, ńto ukazuje na uspostavljanjehemijskih interakcija izmeĊu adsorbata i slobodnih mesta na povrńini adsorbenata. Veber–Morisovkinetiĉki model je pokazao da brzinu adsorpcije odreĊuju i intraĉestiĉna difuzija i difuzija krozgraniĉni sloj.Proces adsorpcije se u sluĉaju Su, Sa i Sa–HAp najbolje opisuje Langmirovim modelom, ńtoukazuje da dolazi do monoslojne adsorpcije. Adsorpcioni kapaciteti Sa–HAp pri svim ispitivanimtemperaturama su bili veći u odnosu na adsorpcione kapacitete Sa i Su. Pretpostavlja se da jedeponovanje HAp–a na Sa dovelo do povećanja broja hidroksilnih grupa, ńto je pored postojećihamino grupa u Sa, uvedenih zahvaljujući alkalnom tretmanu, dodatno doprinelo većemadsorpcionom kapacitetu Sa–HAp u odnosu na Sa i Su.Proces adsorpcije se u sluĉaju (Al,Fe)2O3, (Al,Fe)2O3APTES i SaCPC–(Al,Fe)2O3APTESnajbolje opisuje Frojndlihovim modelom, odnosno adsorpcija je vińeslojna sa heterogenomraspodelom aktivnih centara na povrńini materijala. Adsorpcioni kapaciteti SaCPC–(Al,Fe)2O3APTES pri svim ispitivanim temperaturama su bili veći u odnosu na adsorpcionekapacitete Sa i (Al,Fe)2O3APTES. Iako povrńinska modifikacija aminosilanom ((Al,Fe)2O3APTES)nije dovela do povećanja specifiĉne povrńine, u odnosu na strukturno modifikovan materijal((Al,Fe)2O3), veći adsorpcioni kapaciteti aminofunkcionalizovanog materijala su posledicafunkcionalnosti povrńine.Adsorpcioni kapaciteti hibridnih materiala SaCPC–(Al,Fe)2O3APTES i Sa–HAp za Pb2+,Cd2+ i Ni2+ na poĉetnoj pH = 6, odnosno 6,5 su veći od kapaciteta polaznih materijala (Su, Sa,(Al,Fe)2O3 i (Al,Fe)2O3APTES) zahvaljujući manjem stepenu aglomeracije i time većoj dostupnostipovrńine. Za sve jone i ispitivane materijale povińenje temperature dovodi do povećanjaadsorpcionog kapaciteta, ńto ukazuje da je proces adsorpcije endoterman.

Opis (srp)

Tehnolońko inženjerstvo - Hemijsko inženjerstvo / Technological Engineering- Chemical Engineering Datum odbrane: 22.09.2022.

Jezik

srpski

Datum

2022

Licenca

Ovo delo je licencirano pod uslovima licence
Creative Commons CC BY-NC 3.0 AT - Creative Commons Autorstvo - Nekomercijalno 3.0 Austria License.

http://creativecommons.org/licenses/by-nc/3.0/at/legalcode

Predmet

OSNO - Opšta sistematizacija naučnih oblasti, Hemijsko inženjerstvo

Handkea utriformis, subgleba, modifikacija, γ-aluminijum–oksid, gvožđe(III)–oksid, aminosilan, hidroksiapatit, teški metali, šaržna adsorpcija

OSNO - Opšta sistematizacija naučnih oblasti, Hemijsko inženjerstvo

Handkea utriformis, subgleba, modification, γ–alumina, iron(III)–oxide, aminosilane, hydroxyapatite, heavy metals, batch adsorption