1. Magnetic clay as catalyst applied to organics degradation in a combined adsorption and Fenton-like process.
- Author
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Xu, Ximeng, Chen, Weiming, Zong, Shaoyan, Ren, Xu, and Liu, Dan
- Subjects
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CLAY catalysts , *FISCHER-Tropsch process , *ADSORPTION (Chemistry) , *DRINKING water , *SCANNING electron microscopy , *TRANSMISSION electron microscopy - Abstract
• Magnetite nanoparticle supported on sepiolite (Fe 3 O 4 -Sep) was fabricated. • Fe 3 O 4 -Sep showed high adsorption ability toward BPA. • Adsorbed BPA can be degraded in-situ via Fenton-like process. • Columnar Fe 3 O 4 -Sep remained stable in the fixed-bed reactor under continuous-flow. • Influence of real water matrix on the combined processes was negligible. In this work, a magnetic sepiolite composite was prepared by chemical co-precipitation method and firstly applied as both adsorbent and catalyst for the removal of bisphenol A (BPA) through a heterogeneous Fenton process. The composite was characterized by XPS, XRD, SEM and TEM techniques. The results of the kinetics study indicate that BPA (50 mg·L−1) can be adsorbed onto the composite via electrons transfer as well as π-π interaction, and then be completely degraded at pH 6.0 within 30 min after the addition of H 2 O 2 (1000 mg·L−1). The analysis of FTIR confirms that the degradation occurred through a combined process of adsorption and oxidation. BPA was pre-concentrated and fixed onto the composite surface and then degraded in-situ by hydroxyl radicals, which were generated through the interaction between H 2 O 2 and surface active sites. To investigate the stability and regeneration properties of the catalyst, the powder composite was extruded into a small cylindrical sample and loaded in a fixed-bed reactor, which was operated under continuous-flow condition. The BPA removal efficiency after 4 h remained at 87%, while the leaching of Fe ions gradually increased. Further, degradation tests in different real waters including tap water and municipal wastewater spiked with BPA (50 μg·L−1) reveal that the influence of real matrix on the oxidation ability was very little. The findings of this study confirm the composite as a promising material for the catalytic removal of organics via the coupled adsorption-oxidation process. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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