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32. Enhanced adsorption of bisphenol A and sulfamethoxazole by a novel magnetic CuZnFe 2 O 4 -biochar composite.

Author

Heo J, Yoon Y, Lee G, Kim Y, Han J, and Park CM

Subjects
Adsorption, Hydrophobic and Hydrophilic Interactions, Magnetics, Benzhydryl Compounds chemistry, Charcoal chemistry, Ferric Compounds chemistry, Phenols chemistry, Sulfamethoxazole chemistry
Abstract

The widespread occurrence of endocrine-disrupting compound and pharmaceutical active compounds such as bisphenol A (BPA) and sulfamethoxazole (SMX) in natural freshwater resources can cause serious environmental problems even at low exposure levels. In this work, in order to remove BPA and SMX from aqueous solutions, a novel biochar-supported magnetic CuZnFe 2 O 4 composite (CZF-biochar) was synthesized by a facile one-pot hydrothermal process. After characterization studies, the key factors affecting BPA and SMX adsorption on CZF-biochar were comprehensively investigated. The primary mechanisms for BPA and SMX adsorption included charge-assisted H-bonding, hydrophobic, and π-π electron donor-acceptor interactions. In summary, considering the fast kinetics, high adsorption properties, easy magnetic separation, and recyclability for multiple reuses, the CZF-biochar composite has potential for the removal of BPA, SMX, and potentially other emerging organic contaminants from contaminated soil and water., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Published
2019
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33. Fabrication of graphene-oxide/β-Bi 2 O 3 /TiO 2 /Bi 2 Ti 2 O 7 heterojuncted nanocomposite and its sonocatalytic degradation for selected pharmaceuticals.

Author

Lee G, Chu KH, Al-Hamadani YAJ, Park CM, Jang M, Heo J, Her N, Kim DH, and Yoon Y

Subjects
Catalysis, Graphite chemistry, Nanocomposites chemistry, Titanium chemistry
Abstract

A graphene-oxide (GO)/β-Bi 2 O 3 /TiO 2 /Bi 2 Ti 2 O 7 heterojuncted nanocomposite, designated as GBT, was synthesized via a two-step hydrothermal process. The sonocatalytic activity of the GBT was evaluated at several frequencies (28, 580, and 970 kHz) and compared with Bi-doped GO (GB) and Ti-doped GO (GT). Transmission electron microscopy images showed heterojuncted crystal structures of Bi and Ti on GO, and X-ray diffraction patterns verified that the crystal structures consisted of β-Bi 2 O 3 , TiO 2 , and Bi 2 Ti 2 O 7 nanocomposites. Energy-dispersive X-ray spectroscopy revealed a higher proportion of metal on GBT surfaces compared with GB and GT surfaces. The energy band gaps of GT, GB, and GBT were 3.0, 2.8, and 2.5 eV, respectively. Two pharmaceuticals (PhACs; carbamazepine [CBZ] and acetaminophen [ACE]) were selected and treated under sonolytic conditions at frequencies of 28, 580, and 970 kHz at a power level of 180 W L -1 . The selected pharmaceuticals, present at initial concentrations of 20 μM, were reduced by over 99% by ultrasonic irradiation in the presence of GBT. The 580 kHz treatment achieved the most rapid organic removal among the frequencies tested. The removal kinetic of CBZ was higher than that of ACE owing to its relatively high hydrophobicity. High sonocatalytic activity of GBT was observed through measurement of H 2 O 2 in solution. Because of its low band gaps and high surface activity, GBT exhibited higher sonolytic activity in removing selected PhACs than GT or GB., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Published
2018
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