Carbon-encapsulated iron nanoparticles as reusable adsorbents for micropollutants removal from water
Entity
UAM. Departamento de Ingeniería QuímicaPublisher
ElsevierDate
2020-11-01Citation
10.1016/j.seppur.2020.117974
Separation and Purification Technology 257 (2021): 117974
ISSN
1383-5866 (print)DOI
10.1016/j.seppur.2020.117974Funded by
This research has been supported by the Spanish MINECO through the project CTM-2016-76454-R and by the CM through the project P2018/EMT-4341. M. Munoz and J. Nieto-Sandoval thank the Spanish MINECO for the Ramón y Cajal postdoctoral contract (RYC-2016-20648) and the FPI predoctoral grant (BES-2017-081346), respectivelyProject
Gobierno de España. CTM-2016-76454-REditor's Version
https://doi.org/10.1016/j.seppur.2020.117974Subjects
Adsorption; Carbon-encapsulated iron nanoparticles; CWPO; Micropollutant; QuímicaRights
© 2020 Elsevier B.V.Esta obra está bajo una licencia de Creative Commons Reconocimiento-NoComercial-SinObraDerivada 4.0 Internacional.
Abstract
Adsorption represents the most plausible technology for micropollutants removal from water nowadays. Nevertheless, the regeneration of the saturated carbon materials is still an important challenge, being these solids in practice commonly disposed. This work aims at overcoming this issue by using innovative carbonencapsulated iron nanoparticles (CE-nFe). This material was synthesized by a low-cost and green method viz. hydrothermal carbonization (HTC), using olive mill wastewater as carbonaceous source. The solid was fully characterized by different techniques (magnetic properties, elemental analyses, N2-sorption isotherms, pHPZC, ICP, XRD and TEM). It showed a clear core-shell structure of around 40 nm in diameter. The core was mainly formed by zero-valent iron and the shell by graphitized carbon. Accordingly, it showed an essentially mesoporous structure, with a specific surface area of 169 m2 g−1 , and a clear hydrophobic character (pHPZC = 10). Its adsorption performance was investigated using three relevant micropollutants (diclofenac (DCF), sulfamethoxazole (SMX) and metronidazole (MNZ)). A very fast removal of the micropollutants was achieved (30 min at the most, with rate constants in the range of 0.11–0.41 g mg−1 min−1 ). The adsorption isotherms revealed the vertical packing of the adsorbate molecules onto the adsorbent active centers, being the data successfully described by the GAB model. The saturated adsorbents were effectively regenerated by heterogeneous Fenton oxidation, taking advantage of the iron core of CE-nFe and the opened mesoporous carbon shell. The regeneration efficiency increased with increasing the operating temperature (25–75 ◦C) and contact time (1–4 h), as well as the H2O2 dose up to 6 g L-1. The micropollutant nature affected the adsorbent regeneration yield in the order: SMX > DCF > MNZ, consistent with their reactivity towards Fenton oxidation
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Google Scholar:Munoz, Macarena
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Nieto-Sandoval, Julia
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Álvarez-Torrellas, Silvia
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Sanz-Santos, Eva
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Calderón, Blanca
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Martínez de Pedro, Zahara
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Larriba, Marcos
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Fullana, Andrés
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García, Juan
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Casas de Pedro, José Antonio
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