ADSORPCIJA BOJILA ZA TEKSTIL NA POROZNOM KOMPOZITNOM NOSAČU

Cilj rada je priprava poroznog kompozitnog nosača na temelju kitozana (Cht) i hidroksiapatita (HAp) za primjenu u adsorpciji bojila Congo Red. Kitozan ima veliki potencijal u pročišćavanju otpadnih voda jer je jeftin materijal dobiven iz prirodnih izvora te je njegova upotreba kao biosorbenata vrlo isplativa. U ovom radu ispitan je adsorpcijski učinak kompozitnog kitozan-hidroksiapatitnog nosača te su rezultati uspoređeni s komercijalnim adsorbensom (aktivnim ugljenom). Sinteza poroznog kompozitnog nosača Cht-HAp s 30% masenog udjela HAp-a u kitozanskoj matrici provedena je metodom toplinski inducirane fazne separacije uz geliranje i ekstrakciju. Sastav pripravljenih nosača utvrđen je infracrvenom spektroskopijom s Fourierovim transformacijama te rendgenskom difrakcijskom analizom, dok je morfologija nosača dobivena pretražnom elektronskom mikroskopijom. Za dodatnu karakterizaciju materijala nosača određen je kapacitet bubrenja, tlačna čvrstoća te poroznost. Potvrđeno je in situ nastajanje hidroksiapatita unutar kitozanske matrice te zadovoljavajuća adsorpcija bojila Congo Red na istraživani kompozitni nosač. Detaljno je proučavan utjecaj početne koncentracije i temperature na uklanjanje Congo Red-a. Daljnja ispitivanja potvrdila su dobro opisivanje adsorpcije pomoću Freundlichove i Temkinove izoterme za kitozanski i kompozitni nosač, dok je Langmuirova izoterma prikladna za adsorpciju na aktivnom ugljenu. The aim of this work was the preparation of porous composite scaffold based on chitosan (Cht) and hydroxyapatite (HAp) for application in the Congo Red dye adsorption. Chitosan possesses high potential in waste water treatment as a cost-effective material derived from natural sources and its usage as a biosorbent is highly economical. In this work, the adsorption capacity of composite chitosan-hydroxyapatite scaffold was investigated and the results were compared with a commercial adsorbent (activated carbon). Synthesis of porous composite Cht-HAp scaffold with 30 mass% of HAp within chitosan matrix has been performed by a thermally induced phase separation method with gelation and extraction. Composition of prepared scaffolds were determined by Fourier-transforman spectroscopy and X-ray diffraction analysis, while the scaffold's morphology was imaged by scanning electron microscope. As an additional characterization of the scaffold, swelling capacity, compressive strenght and porosity were determined. The in situ formation of hydroxyapatite within the chitosan matrix and satisfying dye adsorption of Congo Red on the composite scaffold were confirmed. The impact of the initial concentration and temperature was studied on the removal of Congo Red dye. Further studies have confirmed good fitting of Freundlich and Temkin isotherms for chitosan and composite scaffolds, while Langmuir isotherm is suitable for adsorption on activated carbon.