Silicate-Enhanced Heterogeneous Flow-Through Electro-Fenton System Using Iron Oxides under Nanoconfinement

2021 ◽  
Author(s):  
Dongli Guo ◽  
Yanbiao Liu ◽  
Haodong Ji ◽  
Chong-Chen Wang ◽  
Bo Chen ◽  
...  
Keyword(s):  
Iron Oxides ◽  
Heterogeneous Flow ◽  
Flow Through ◽  
Fenton System

Microstructure, Stiffness and Corrosion of Bare and Phosphated Specimens Made by Sintering of Structured Iron-Iron Oxide Spheres

2020 ◽  
Vol 405 ◽  
pp. 411-416
Author(s):  
Miriam Kupková ◽  
Martin Kupka ◽  
Renáta Oriňáková ◽  
Radka Gorejová
Keyword(s):  
Iron Oxide ◽  
Iron Oxides ◽  
Metallic Iron ◽  
Galvanic Corrosion ◽  
Iron Phosphate ◽  
Reduction Reaction ◽  
Diffusion Control ◽  
Iron Oxide Particles ◽  
Flow Through ◽  
Iron Iron

Granulated iron oxide particles were incompletely reduced to structured particles comprised metallic iron and residual iron oxides. Structured particles were pressed into prismatic compacts and sintered. Some of sintered specimens were subsequently phosphatized and calcined. Specimens with an iron phosphate coating were found stiffer than specimens without coating. In Hanks' solution, a galvanic corrosion was induced by more noble iron oxides coupled to a less noble metallic iron. This could explain higher corrosion potentials and higher rates of iron dissolution in comparison with a pure iron. The coating of specimens with iron phosphates shifted corrosion potentials towards more negative values and slowed down the dissolution of iron. This was most likely caused by a reduction in oxygen flow through the coating to iron-oxide cathodes, which has enhanced the influence of diffusion control on the kinetics of reduction reaction.

A highly efficient flow-through electro-Fenton system enhanced with nitrilotriacetic acid for phenol removal at neutral pH

2019 ◽  
Vol 697 ◽  
pp. 134173 ◽  
Author(s):  
Yinqiao Zhang ◽  
Qizhan Zhang ◽  
Sijin Zuo ◽  
Minghua Zhou ◽  
Yuwei Pan ◽  
...  
Keyword(s):  
Nitrilotriacetic Acid ◽  
Phenol Removal ◽  
Neutral Ph ◽  
Highly Efficient ◽  
Flow Through ◽  
Fenton System

scholarly journals Efficient H2O2 generation and electro-Fenton degradation of pollutants in microchannels of oxidized monolithic-porous-carbon cathode

2019 ◽  
Vol 80 (5) ◽  
pp. 970-978
Author(s):  
Yunfei Guo ◽  
Shuai Wu ◽  
Hongtao Yu ◽  
Shuo Chen ◽  
Chunna Wang ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Organic Pollutants ◽  
Porous Carbon ◽  
Hydraulic Retention Time ◽  
Fenton Process ◽  
Initial Concentration ◽  
H2o2 Generation ◽  
Flow Through ◽  
Fenton System ◽  
Degradation Of Pollutants

Abstract A monolithic-porous carbon (MPC) was fabricated by carbonizing a pine rod, and then the oxidized monolithic-porous carbon (O-MPC) was obtained via alkaline heat treatment of MPC. With well-ordered axial channels (diameters were 6–14 μm and 40–50 μm) and oxygen-containing functional groups, O-MPC as a flow-through cathode exhibited good capability in continuously generating H2O2 (422 μmol/L) via oxygen reduction. O-MPC and additional Fe2+ composed an electro-Fenton system and the performance of the system in degradation of organic pollutants was evaluated. For phenol, bisphenol A or sulfamethoxazole at initial concentration of 10 mg/L the removal efficiency reached 74%–82% in a hydraulic retention time of 100 seconds, nearly close to that of the homogeneous Fenton process (90%). This efficiency may be maintained for at least 10 hours, indicating a good stability of O-MPC. The results demonstrate the potential of O-MPC as a flow-through electrode to realize homogeneous-like degradation of organic pollutants in wastewater.

Signature of coalescence during scalar mixing in heterogeneous flow fields

2020 ◽  
Author(s):  
Sabyasachi Sen ◽  
Prajwal Singh ◽  
Joris Heyman ◽  
Tanguy Le Borgne ◽  
Aditya Bandopadhyay
Keyword(s):  
Porous Media ◽  
Fluid Mechanics ◽  
Large Scale ◽  
Scalar Fields ◽  
Flow Fields ◽  
Scalar Mixing ◽  
Heterogeneous Flow ◽  
Strip Method ◽  
Mixing Rates ◽  
Flow Through

<p>Stretching of fluid elements by a heterogeneous flow field, such as the flow through a porous media or geophysical flows such as atmospheric or oceanic vortices, is known to enhance mixing rates of scalar fields[1]. While the mechanisms leading to the elongation of material lines are well understood, predicting mixing rates still remains a challenge particularly when there is a reconnection (or aggregation) between several parts of the mixing interface, leading, at large mixing time, to a so-called coalescence regime[1][2]. In this presentation, we numerically study this coalescence dynamics through scalar transport in two different flow fields, the Rankine vortex and Stokes flow through a periodic bead pack[3]. The former is typical of large-scale turbulent flows [4] whereas the second is generic of small-scale laminar flows in porous media [5]. Both flows show a net elongation of the mixing interfaces, although at very different rates. To solve the transport problem in these flows, we use a Lagrangian method (the diffusive strip method[6]). This method allows us to reconstruct, at high resolution, the scalar concentration fields and to compute the evolution of the distribution of concentrations levels, scalar dissipation rate and scalar power spectrum in time. The signature of coalescence is clearly observed in both flows and we assess the influence of coalescence on the difference in mixing behaviour for the two flows. We finally discuss how coalescence may affect the reaction kinetics of mixing-limited reactive flows. The analysis proposed sheds light on fundamental aspects of transport and mixing in earth surface and subsurface flows.</p><p>[1] Emmanuel Villermaux. Mixing versus stirring. Annual Review of Fluid Mechanics, 51:245–273, 2019.<br>[2] Tanguy Le Borgne, Marco Dentz, and Emmanuel Villermaux. The lamellar description of mixing in porous media. Journal of Fluid Mechanics, 770:458–498, 2015.<br>[3] Régis Turuban, David R Lester, Tanguy Le Borgne, and Yves Méheust. Space-group symmetries generate chaotic fluid advection in crystalline granular media. Physical review letters, 120(2):024501, 2018.<br>[4] RT Pierrehumbert. Large-scale horizontal mixing in planetary atmospheres. Physics of Fluids A: Fluid Dynamics, 3(5):1250–1260, 1991.<br>[5] Brian Berkowitz, Andrea Cortis, Marco Dentz, and Harvey Scher. Modeling non-fickian transport in geological formations as a continuous time random walk. Reviews of Geophysics, 44(2), 2006.<br>[6] Patrice Meunier and Emmanuel Villermaux. The diffusive strip method for scalar mixing in two dimensions. Journal of fluid mechanics, 662:134–172, 2010.</p>

Degradation of florfenicol in a flow-through electro-Fenton system enhanced by wood-derived block carbon (WBC) cathode

2022 ◽  
Author(s):  
Li Tian ◽  
Qiongfang Zhuo ◽  
Jincheng Lu ◽  
Jingjing Liu ◽  
Xiaofeng Xu ◽  
...  
Keyword(s):  
Flow Through ◽  
Fenton System

A computational model for heterogeneous flow through low headloss biofilter media

2002 ◽  
Vol 21 (1) ◽  
pp. 11-19 ◽  
Author(s):  
Derek E. Chitwood ◽  
Joseph S. Devinny ◽  
Eckart Meiburg
Keyword(s):  
Computational Model ◽  
Heterogeneous Flow ◽  
Flow Through

Characterization of a tropical soil and a waste from kaolin mining and their suitability as heterogeneous catalysts for Fenton and Fenton-like reactions

Clay Minerals ◽  
2007 ◽  
Vol 42 (3) ◽  
pp. 299-306 ◽  
Author(s):  
M. C. Pereira ◽  
C. M. Tavares ◽  
J. D. Fabris ◽  
R. M. Lago ◽  
E. Murad ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Chemical Analysis ◽  
Iron Oxides ◽  
Heterogeneous Catalysts ◽  
Tropical Soil ◽  
X Ray Diffraction ◽  
X Ray ◽  
Catalytic Activities ◽  
Fenton System

AbstractAlternative Fenton and Fenton-like systems based on natural Fe oxides are described. The collected materials were modified through controlled reduction with H2 and were characterized by chemical analysis, X-ray diffraction, saturation magnetization measurements, and Mössbauer spectroscopy at 298 and 110 K. The catalytic activities of these original and modified materials were tested by studying the decomposition of H2O2 and the discolouration of methylene blue. Iron oxides present in the samples were mainly hematite and subordinate goethite which, after controlled reduction, were converted to metallic iron and magnetite. The mixture of Fe0 and magnetite in one of these materials was significantly more efficient at H2O2 decomposition and the discolouration of methylene blue than the original Fe3+ oxides. These results suggest that Fe2+ is essential to produce an active Fenton system.

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