Role of electrode materials for the anodic oxidation of a real landfill leachate – Comparison between Ti–Ru–Sn ternary oxide, PbO2 and boron-doped diamond anode

Chemosphere ◽  
2013 ◽  
Vol 90 (4) ◽  
pp. 1455-1460 ◽  
Author(s):  
Marco Panizza ◽  
Carlos A. Martinez-Huitle
2010 ◽  
Vol 162 (3) ◽  
pp. 1012-1018 ◽  
Author(s):  
Joaquín R. Domínguez ◽  
T. González ◽  
P. Palo ◽  
J. Sánchez-Martín

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Monika Kosowska ◽  
Paweł Jakóbczyk ◽  
Michał Rycewicz ◽  
Alex Vitkin ◽  
Małgorzata Szczerska

AbstractWe present an advanced multimodality characterization platform for simultaneous optical and electrochemical measurements of ferrocyanides. Specifically, we combined a fiber-optic Fabry–Perot interferometer with a three-electrode electrochemical setup to demonstrate a proof-of-principle of this hybrid characterization approach, and obtained feasibility data in its monitoring of electrochemical reactions in a boron-doped diamond film deposited on a silica substrate. The film plays the dual role of being the working electrode in the electrochemical reaction, as well as affording the reflectivity to enable the optical interferometry measurements. Optical responses during the redox reactions of the electrochemical process are presented. This work proves that simultaneous opto-electrochemical measurements of liquids are possible.


2006 ◽  
Vol 53 (4) ◽  
pp. 839-844 ◽  
Author(s):  
Chia-Chin Changa ◽  
Li-Chia Chena ◽  
Shyh-Jiun Liu ◽  
Hsien-Ju Tien ◽  
Hsien-Chang Chang

2018 ◽  
Vol 2018 ◽  
pp. 1-9
Author(s):  
Armando Vázquez ◽  
Lucía Alvarado ◽  
Isabel Lázaro ◽  
Roel Cruz ◽  
José Luis Nava ◽  
...  

2-(Thiocyanomethylthio)-benzothiazole (TCMTB) is used as fungicide in the paper, tannery, paint, and coatings industries, and its study is important as it is considered toxic to aquatic life. In this study, a comparison of direct anodic oxidation (AO) using a boron-doped diamond electrode (BDD) and electro-Fenton (EF) processes for TCMTB degradation in acidic chloride and sulfate media using a FM01-LC reactor was performed. The results of the electrolysis processes studied in the FM01-LC reactor showed a higher degradation of TCMTB with the anodic oxidation process than with the electro-Fenton process, reaching 81% degradation for the former process versus 47% degradation for the latter process. This difference was attributed to the decrease in H2O2 during the EF process, due to parallel oxidation of chlorides. The degradation rate and current efficiency increased as a function of volumetric flow rate, indicating that convection promotes anodic oxidation and electro-Fenton processes. The results showed that both AO and EF processes could be useful strategies for TCMTB toxicity reduction in wastewaters.


2005 ◽  
Vol 50 (18) ◽  
pp. 3685-3692 ◽  
Author(s):  
Cristina Flox ◽  
José Antonio Garrido ◽  
Rosa María Rodríguez ◽  
Francesc Centellas ◽  
Pere-Lluís Cabot ◽  
...  

Sensors ◽  
2018 ◽  
Vol 18 (7) ◽  
pp. 2178 ◽  
Author(s):  
Shaili Falina ◽  
Sora Kawai ◽  
Nobutaka Oi ◽  
Hayate Yamano ◽  
Taisuke Kageura ◽  
...  

Author(s):  
Alicia Garcia-Costa ◽  
André Savall ◽  
Juan A. Zazo ◽  
Jose A. Casas ◽  
Karine Groenen Serrano

Perfluorooctanoic acid (PFOA), C7F15COOH, has been widely employed over the past fifty years, causing an environmental problem due to its dispersion and low biodegradability. Furthermore, the high stability of this molecule, conferred by the high strength of the C-F bond makes it very difficult to remove. In this work, electrochemical techniques are applied for PFOA degradation in view to study the influence of the cathode on defluorination. For this purpose, boron doped diamond (BDD), Pt, Zr and stainless steel have been tested as cathodes working with BDD anode at low electrolyte concentration (3.5 mM) to degrade PFOA at 100 mg/L. Among these cathodic materials, Pt improves the defluorination reaction. The electro-degradation of a PFOA molecule starts by a direct exchange of one electron at the anode and then follows a complex mechanism involving reaction with hydroxyl radicals and adsorbed hydrogen on the cathode. It is assumed that Pt acts as an electrocatalyst, enhancing PFOA defluorination by the reduction reaction of perfluorinated carbonyl intermediates on the cathode. The defluorinated intermediates are then more easily oxidized by HO• radicals. Hence, high mineralization (xTOC: 76.1%) and defluorination degrees (xF-: 58.6%) were reached with Pt working at current density j = 7.9 mA/cm2. This BDD-Pt system reaches a higher efficiency in terms of defluorination for a given electrical charge than previous works reported in literature. Influence of the electrolyte composition and initial pH are also explored.


2019 ◽  
Vol 79 (5) ◽  
pp. 921-928 ◽  
Author(s):  
F. Agustina ◽  
A. Y. Bagastyo ◽  
E. Nurhayati

Abstract Electro-oxidation using a boron-doped diamond (BDD) anode can be used as an alternative to leachate treatment. Aside from the hydroxyl radical, BDDs are capable of generating chloride and sulfate radical species that play significant roles in the oxidation of pollutants. This research investigated the role of Cl−:SO42− ions at molar ratios of 237:1, 4:1 and 18:1, and the influence of applied current density (i.e. 50, 75 and 100 mA cm−2) on the removal of organic and ammonium contaminants. The results show that current density had considerable effects on chemical oxygen demand (COD) and colour removal, while ion composition of Cl−:SO42− at pH 3, 5 and 8.5 (original pH) gave different effects on COD and ammonium removal. The pH had a significant effect on the COD removal at the ratio of 237:1, but showed no dramatic effect at the ratio of 18:1, giving ∼40% of COD removal at all pHs tested. This indicates that electro-oxidation at the ratio of 18:1 could be effectively conducted at a wide range of pH. Furthermore, the optimum ammonium removal was obtained at pH 8.5 with the ratio of 237:1. This process was found to be ineffective in increasing the biodegradability index of the leachate; instead, it exhibited mineralization of organic content.


Catalysts ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 902
Author(s):  
Alicia L. Garcia-Costa ◽  
Andre Savall ◽  
Juan A. Zazo ◽  
Jose A. Casas ◽  
Karine Groenen Serrano

Perfluorooctanoic acid (PFOA), C7F15COOH, has been widely employed over the past fifty years, causing an environmental problem because of its dispersion and low biodegradability. Furthermore, the high stability of this molecule, conferred by the high strength of the C-F bond makes it very difficult to remove. In this work, electrochemical techniques are applied for PFOA degradation in order to study the influence of the cathode on defluorination. For this purpose, boron-doped diamond (BDD), Pt, Zr, and stainless steel have been tested as cathodes working with BDD anode at low electrolyte concentration (3.5 mM) to degrade PFOA at 100 mg/L. Among these cathodic materials, Pt improves the defluorination reaction. The electro-degradation of a PFOA molecule starts by a direct exchange of one electron at the anode and then follows a complex mechanism involving reaction with hydroxyl radicals and adsorbed hydrogen on the cathode. It is assumed that Pt acts as an electrocatalyst, enhancing PFOA defluorination by the reduction reaction of perfluorinated carbonyl intermediates on the cathode. The defluorinated intermediates are then more easily oxidized by HO• radicals. Hence, high mineralization (xTOC: 76.1%) and defluorination degrees (xF−: 58.6%) were reached with Pt working at current density j = 7.9 mA/cm2. This BDD-Pt system reaches a higher efficiency in terms of defluorination for a given electrical charge than previous works reported in literature. Influence of the electrolyte composition and initial pH are also explored.


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