Magnetically modified natural biogenic iron oxides for organic xenobiotics removal

0442375 - ÚVGZ 2015 RIV GB eng A - Abstrakt
Šafařík, Ivo - Filip, J. - Horská, Kateřina - Nowakova, M. - Tuček, J. - Šafaříková, Miroslava - Hashimoto, H. - Takada, J. - Zbořil, R.
Magnetically modified natural biogenic iron oxides for organic xenobiotics removal.
Current Opinion in Biotechnology. Elsevier. Roč. 24, S1 (2013), S77-S77. ISSN 0958-1669. E-ISSN 1879-0429.
[European Biotechnology Congress. 16.05.2013-18.05.2013, Bratislava]
Institucionální podpora: RVO:67179843
Klíčová slova: organic xenobiotics * biogenic iron * Magnetically modified
Kód oboru RIV: EI - Biotechnologie a bionika
http://ac.els-cdn.com/S0958166913003340/1-s2.0-S0958166913003340-main.pdf?_tid=55b04b50-cbc0-11e4-8cb5-00000aab0f6c&acdnat=1426498946_517d901283c9cd0d7b198ceb605f1435

Biogenic iron oxides, produced by Leptothrix ochracea in the process of biomineralization, were collected from local water streams. After drying they were magnetically modified using water-based magnetic fluid (ferrofluid) stabilized with perchloric acid. Magnetic modification of this material increased the potential applicability in large scale processes. Both natural and magnetically modified materials were characterized in detail utilizing state-of-the-art multi-analytical approach (wavelength dispersive X-ray fluorescence spectrometry, X-ray powder diffraction, Mössbauer spectroscopy, SEM, TEM and BET surface area measurements). The natural material was composed of 2-line ferrihydrite, forming hollow microtubules – sheaths of Leptothrix ochracea, and detrital components. As a result of the ferrofluid modification, maghemite nanoparticles were identified on the surface of the treated material. The active surface area of the bulk, magnetically modified sample was 148 m2 g−1. The formed magnetic material was tested as inexpensive magnetically responsive adsorbent for the removal of selected organic xenobiotics, namely 7 hazardous water soluble organic dyes belonging to different dye classes, from aqueous solutions. In order to achieve equilibrium of adsorption process, incubation time of 3 h was used. Equilibrium adsorption data were fit to Langmuir and Freundlich adsorption isotherms. Biogenic iron oxides exhibited high adsorption capacity for selected organic xenobiotics: the observed maximum adsorption capacities ranged between 34.3 and 97.8 mg of dye per one gram of magnetic adsorbent which is at least comparable with literature data for other similar iron-rich sorbents, both in magnetic and non-magnetic forms.
Trvalý link: http://hdl.handle.net/11104/0245226