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Removal of lead ions from aqueous solutions by using the natural and Fe(III)-modified zeolite

dc.contributor.advisorDondur, Vera
dc.contributor.otherDaković, Aleksandra
dc.contributor.otherDamjanović, Ljiljana
dc.creatorKragović, Milan M.
dc.date.accessioned2016-07-23T16:14:27Z
dc.date.available2016-07-23T16:14:27Z
dc.date.available2020-07-03T09:32:54Z
dc.date.issued2014-04-04
dc.identifier.urihttp://eteze.bg.ac.rs/application/showtheses?thesesId=3292
dc.identifier.urihttp://nardus.mpn.gov.rs/handle/123456789/5997
dc.identifier.urihttps://fedorabg.bg.ac.rs/fedora/get/o:11734/bdef:Content/download
dc.identifier.urihttp://vbs.rs/scripts/cobiss?command=DISPLAY&base=70036&RID=47575311
dc.description.abstractGvožđe oksidi i prirodni zeoliti su efikasni adsorbenti jona teških metala iz vodenih rastvora. Međutim, kako bi se unapredile adsorpcione osobine i gvožđe oksida i prirodnih zeolita prema različitim zagađivačima, gvožđe oksidi se često impregniraju na površine poroznih zeolitskih minerala. Kako bi se dobio efikasniji adsorbent jona olova iz vodenih rastvora, u ovoj doktorskoj disertaciji je urađena modifikacija prirodnog zeolita-klinoptilolita iz ležišta Zlatokop, Vranjska Banja u Srbiji kombinacijom metoda za dobijanje getita i gvožđe prekrivenog zeolita u baznoj sredini. Pri tome je dobijen Fe(III)-modifikovani zeolit - kompozit prirodnog zeolita i getita. Prirodni i Fe(III)-modifikovani zeolit su okarakterisani određivanjem hemijskog sastava, kapaciteta katjonske izmene (KKI), tačke nultog naelektrisanja (pHpzc), teksturalnih osobina, kao i rendgenskom difrakcionom analizom (XRPD), skenirajućom elektronskom mikroskopijom i energijsko-disperzivnom rendgenskom spektroskopskom analizom (SEM-EDS), termijskom analizom (TGA/DTA), infracrvenom spektroskopijom (FTIC) i transmisionom elektronskom mikroskopijom (TEM). Pokazano je da se modifikacijom ne menjaju značajnije kristalna struktura minerala klinoptilolita, Si/Al odnos, kao ni morfološke, termijske i strukturne osobine polaznog zeolita. Međutim, kapacitet katjonske izmene Fe(III)-modifikovanog je znatno veći nego prirodnog zeolita, dok su SEM-EDS ispitivanja površina oba adsorbenta pokazala da su sadržaji gvožđa i kalijuma na površini Fe(III)-modifikovanog zeolita znatno veći, a sadržaji natrijuma i kalcijuma manji u odnosu na prirodni zeolit. Tačka nultog nalelektrisanja se povećava nakon modifikacije sa 6,8 na 7,5, tako da je između pHpzc getita (pHpzc=9,4) i prirodnog zeolita, što ukazuje da je došlo do stvaranja mešanog sistema gvožđa oksida i klinoptilolita na površini zeolita. Znatno uži dobijeni plato ukazuje da je površina modifikovanog znatno više negativno naelektrisana u odnosu na prirodni zeolit. Specifična površina (SBET) nakon modifikacije jonima gvožđa se značajno povećava, sa 30,2 m2/g na 52,5 m2/g i približno je jednaka specifičnoj površini čistog getita – 55,5 m2/g. Takođe, povećane su i zapremine mikro- i mezopora, kao i ukupna zapremina pora, što potvrđuje da je formirana nova faza bogata gvožđem na površini zeolita. TEM ispitivanja su pokazala i da je dobijeni Fe(III)-modifikovani zeolit nano-kompozit zeolita i gvožđe oksida. Ispitivanje adsorpcije jona olova iz vodenih rastvora na prirodnom i Fe(III)-modifikovanom zeolitu urađeno je pri različitim uslovima: početnom pH, koncentraciji jona olova, veličini čestica adsorbenata, temperaturi, masi adsorbenata, vremenu. Utvrđeno je da se modifikacijom jonima gvožđa u rastvoru KOH adsorpcioni kapacitet prirodnog zeolita znatno povećava (sa 64 meq/100 g kod prirodnog na 128 meq/100 g kod Fe(III)-modifikovanog zeolita). Takođe, vezivanje jona olova na oba adsorbenta se odvija jonskom izmenom (koja je dominantna pri nižim polaznim koncentracijama jona olova) i hemisorpcijom (koja je dominantna pri višim polaznim koncentracijama jona olova) pri čemu je, pri nižim polaznim koncentracijama, vezivanje jona olova praćeno i...sr
dc.description.abstractIron oxides and natural zeolites are efficient adsorbents of heavy metals ions from aqueous solutions. However, to improve their adsorption properties toward different pollutants iron oxides are often impregnated at the surface of porous zeolites. In order to obtain a more efficient adsorbent of lead ions from aqueous solution, in this dissertation modification of natural zeolite-clinoptilolite from Zlatokop deposit, Vranjska Banja, Serbia was performed by combining the method for pure goethite preparation and the method for preparation of iron-coated zeolite. The obtained Fe(III)-modified zeolite is a composite of the natural zeolite and the goethite. The characterization of the natural and Fe(III)-modified zeolite was performed by determination of the chemical composition, cation exchange capacity (CEC), point of the zero charge (pHpzc), textural properties, and by using X-ray powder diffraction analysis (XRPD), scanning electron microscopy and X-ray spectroscopy in energy-dispersive mode (SEM-EDS), thermal analysis (TGA/DTA), infrared spectroscopy (FTIC) and transmission electron microscopy (TEM). It was shown that the modification does not cause any changes in the crystal structure of clinoptilolite, Si/Al ratio, as well as in its morphological, thermal and structural properties. However, CEC of the Fe(III)-modified zeolite was significantly higher than of the natural one, while SEM-EDS analysis of both adsorbents showed that the amounts of iron and potassium at surface of Fe(III)-modified zeolite were higher and the amounts of sodium and calcium were lower than at surface of the natural zeolite. The comparison of pHpzc of the pure goethite (pHpzc=9.4), pHpzc of the natural zeolite (pHpzc=6.8), with pHpzc of Fe(III)-modified zeolite (pHpzc=7.5), indicates formation of Fe-oxide/clinoptilolite mixed system forms at the surface of the natural zeolite. Narower pH range at the plateau was obtained in the case of the Fe(III)-modified zeolite, pointing to a noticeably higher negative surface charge of this adsorbent. Specific surface area significantly increases after modification of the natural zeolite with Fe(III) ions, from 30.20 m2/g for the natural zeolite to 52.50 m2/g for Fe(III)-modified zeolite and is approximately equal to the specific surface of the pure goethite- 55.5 m2/g. Also, Fe(III)-modified zeolite shows increase in both micro- and mesopores volume, confirming formation of new Fe-bearing phases on zeolite. TEM investigations have shown the presence of spherical amorphous nano-clusters on the crystal faces. In order to investigate the mechanism of adsorption of lead ions by the natural and Fe(III)-modified zeolite, experiments were performed under different conditions. The influence of specific parameters, such as initial lead ions concentration, amount of adsorbents, contact time, temperature and particle size on adsorption of lead ions by both adsorbents was studied. It was determined that the adsorption capacity of the natural zeolite significantly increases (from 64 to 128 meq/100 g) after modification with the iron ions in KOH solution. Also, the binding of the lead ions on both adsorbents is carried out by ion exchange (which is dominant at lower starting...en
dc.formatapplication/pdf
dc.languagesr
dc.publisherУниверзитет у Београду, Факултет за физичку хемијуsr
dc.relationinfo:eu-repo/grantAgreement/MESTD/Technological Development (TD or TR)/34013/RS//
dc.relationinfo:eu-repo/grantAgreement/MESTD/Basic Research (BR or ON)/172018/RS//
dc.rightsopenAccessen
dc.sourceУниверзитет у Београдуsr
dc.subjectprirodni zeolitsr
dc.subjectnatural zeoliteen
dc.subjectFe(III)-modified zeoliteen
dc.subjectcrystal nano-compositesen
dc.subjectamorphous aggregates of ironen
dc.subjectlead ionsen
dc.subjectadsorptionen
dc.subjectFe(III)-modifikovani zeolitsr
dc.subjectnano-kompozitsr
dc.subjectamorfni agregati gvožđasr
dc.subjectjoni olovasr
dc.subjectadsorpcija.sr
dc.titleUklanjanje jona olova iz vodenih rastvora upotrebom prirodnog i Fe(III)-modifikovanog zeolitasr
dc.titleRemoval of lead ions from aqueous solutions by using the natural and Fe(III)-modified zeoliteen
dc.typedoctoralThesisen
dc.rights.licenseBY-NC-ND
dcterms.abstractДондур, Вера; Дамјановић, Љиљана; Даковић, Aлександра; Краговић, Милан М.; Уклањање јона олова из водених раствора употребом природног и Фе(ИИИ)-модификованог зеолита; Уклањање јона олова из водених раствора употребом природног и Фе(ИИИ)-модификованог зеолита;
dc.identifier.fulltexthttp://nardus.mpn.gov.rs/bitstream/id/20593/Disertacija3897.pdf


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