In Situ-Formed PdFe Nanoalloy and Carbon Defects in Cathode for Synergic Reduction–Oxidation of Chlorinated Pollutants in Electro-Fenton Process

2020 ◽  
Vol 54 (7) ◽  
pp. 4564-4572 ◽  
Author(s):  
Xuqian Shen ◽  
Fan Xiao ◽  
Hongying Zhao ◽  
Ying Chen ◽  
Chao Fang ◽  
...  
2020 ◽  
Vol 270 ◽  
pp. 110835
Author(s):  
Abdoulaye Thiam ◽  
Ricardo Salazar ◽  
Enric Brillas ◽  
Ignasi Sirés

1991 ◽  
Vol 24 (11) ◽  
pp. 9-17 ◽  
Author(s):  
K. Halden ◽  
H. A. Chase

Aquifers are vital reserves of drinking water which are under threat from pollution. Particular problems are posed by chlorinated compounds such as pesticides and solvents which native microbial populations are unable to degrade. Pump and treat regimes have proved unsuccessful since pollutants remain adsorbed to sediments but a possible solution is the use of introduced microorganisms to degrade pollutants in-situ. It is suggested that methanotrophs may be suitable candidates. Methanotrophs have an extraordinary range of degradative powers due to the non-specificity of their methane mono-oxygenase enzyme. We have shown that Methylosinus trichosporium OB3b is capable of degrading many common chlorinated pollutants co-metabolically when it is grown in a copper-depleted, oxygen-rich medium at neutral pH. In the subsurface however, such conditions do not exist and cultures grown in a medium made with untreated Cambridge aquifer water have a reduced range of degradative powers compared to similar cells grown in a medium made with distilled water. This means that to use methanotrophs for aquifer clean-up, the cells may need to be cultured above ground in ideal conditions and then introduced by some method of injection or infiltration. This may be possible because the degradative reactions are not coupled to growth and Methylosinus trichosporium OB3b cells maintain pollutant degrading ability up to 19 days after they have stopped growing. A suspension of these cells may thus be treated as a biocatalyst.


Author(s):  
Truong Giang Le ◽  
Alain Bermond

AbstractThe Electro-Fenton is one of the processes based on the Fenton reaction, which have been investigated to improve the efficiency of classical Fenton treatment. The Electro-Fenton has been shown to be efficient in the degradation of many organic compounds. However, generally there is no true estimation of its efficiency compared to that of the classical Fenton process. This study aimed to compare the two processes using an experimental approach and modelling. First of all, degradation of hydrogen peroxide (externally applied) was studied. It was shown that the Electro-Fenton process needs smaller quantities of iron (5 times less) than the Fenton to decompose the same quantity of hydrogen peroxide. The Electro-Fenton process may also produce hydrogen peroxide in situ (oxygen reduction). This leads to an important reduction in the consumption of chemicals (hydrogen peroxide, small quantities of iron salt). Finally, a study of the degradation of phenol, when hydrogen peroxide was electrogenerated has shown the greater efficiency of Electro-Fenton compared to the Fenton process.


2017 ◽  
Vol 58 (3) ◽  
Author(s):  
Ivonne Arely González Reyes ◽  
M. E. De Anda Reyes ◽  
Francisco J. Rodríguez Valadez ◽  
Juan Manríquez ◽  
Erika Bustos ◽  
...  

A novel photoelectro-Fenton system was built by coupling a carbon sponge (CS) with a carbon steel plate (CSP). When this system contacts a solution containing orange II dye (OGII) under ultraviolet (UV) irradiation, 68% of the solution color was removed compared with 0% without UV irradiation. The tests indicate that the CS-CSP arrangement releases iron ions, a phenomenon associated with the removal of 23% of the solution color, a percentage similar to that obtained when Fe<sup>2+</sup> and Fe<sup>3+</sup> salts are directly placed into the dye solution. The identification of oxidizing free radicals and the color removal percentages indicate that the CS-CSP coupling can operate as in situ Fenton process.


2016 ◽  
Vol 14 (4) ◽  
pp. 843-850 ◽  
Author(s):  
Orlando García-Rodríguez ◽  
Jennifer A. Bañuelos ◽  
Arturo Rico-Zavala ◽  
Luis A. Godínez ◽  
Francisco J. Rodríguez-Valadez

Abstract The in-situ generation of hydrogen peroxide in the electro-Fenton process is paramount. For this reason, in this research the electrocatalytic activity of three carbon materials was evaluated in the reaction of oxygen reduction via two electrons. Furthermore, in order to eliminate the use of iron salts in solution (homogeneous process), the iron was electrodeposited on the surface of the carbon material and was applied in a heterogeneous electro-Fenton process for the degradation of methyl orange dye. The largest amount of generated H2O2 was achieved with the Carbon Felt (CF) electrode (460 mg L−1) without iron after 60 minutes. The electrodes with electrodeposited iron were characterized by SEM and EDS, which showed that the surface of the Carbon Sponge (CS) electrode had the largest amount of iron (23.84 %). However, the CF electrode showed a greater and faster degradation of the dye (98 %) after 30 minutes of treatment. The CF material was the best and most-viable choice of material compared to the CS and Carbon Cloth (CC) for industrial application in electro-Fenton processes, due to its greater catalytic activity in the production of H2O2, uniform distribution of iron, more efficient TOC removal and lower cost per cm2 of material.


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