Electrochemical advanced oxidation process using DiaChem®electrodes

2004 ◽  
Vol 49 (4) ◽  
pp. 207-212 ◽  
Author(s):  
I. Tröster ◽  
L. Schäfer ◽  
M. Fryda ◽  
T. Matthée
Keyword(s):  
Drinking Water ◽  
Hydroxyl Radicals ◽  
Advanced Oxidation Process ◽  
Oxidation Process ◽  
Chemical Vapour ◽  
Advanced Oxidation ◽  
Water Disinfection ◽  
Efficient Production ◽  
Boron Doped Diamond ◽  
Electrochemical Window

The electrochemical advanced oxidation process (EAOP) using boron doped diamond (DiaChem®, registered trademark of Condias GmbH) has been studied for wastewater treatment and drinking water disinfection. DiaChem® electrodes consist of preferentially metallic base materials coated with a conductive polycrystalline diamond film by hot-filament chemical vapour deposition. They exhibit high overpotential for water electrolysis as well as high chemical inertness and extended lifetime. In particular the high overpotential for water decomposition opens the widest known electrochemical window, allowing the energy efficient production of hydroxyl radicals directly from aqueous solutions. The hydroxyl radicals on the other hand are effectively used for the oxidation of pollutants. The EAOP using DiaChem® electrodes thus facilitates the direct and, if necessary, complete decomposition of even hazardous or persistent pollutants in different wastewaters. Current efficiencies of more than 90%, also without the use of additives for hydroxyl radical generation, have been demonstrated. Additionally, for drinking water preparation diamond electrodes facilitate disinfection with and without the support of chlorine.

Emerging investigators series: the efficacy of chlorine photolysis as an advanced oxidation process for drinking water treatment

2016 ◽  
Vol 2 (4) ◽  
pp. 565-579 ◽  
Author(s):  
C. K. Remucal ◽  
D. Manley
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Hydroxyl Radicals ◽  
Hypochlorous Acid ◽  
Advanced Oxidation Process ◽  
Oxidation Process ◽  
Drinking Water Treatment ◽  
Advanced Oxidation ◽  
Chlorine Radicals ◽  
Reactive Oxidants

The photolysis of hypochlorous acid (HOCl) and hypochlorite (OCl−) produces a suite of reactive oxidants, including hydroxyl radicals (˙OH), chlorine radicals (Cl˙), and ozone (O3).

scholarly journals Fate of Diclofenac and Its Transformation and Inorganic By-Products in Different Water Matrices during Electrochemical Advanced Oxidation Process Using a Boron-Doped Diamond Electrode

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1686 ◽  
Author(s):  
Carolin Heim ◽  
Mohamad Rajab ◽  
Giorgia Greco ◽  
Sylvia Grosse ◽  
Jörg E. Drewes ◽  
...  
Keyword(s):  
Current Density ◽  
Advanced Oxidation Process ◽  
Oxidation Process ◽  
Early Stage ◽  
Advanced Oxidation ◽  
Target Compound ◽  
Duration Of Treatment ◽  
Boron Doped Diamond ◽  
Boron Doped ◽  
By Products

The focus of this study was to investigate the efficacy of applying boron-doped diamond (BDD) electrodes in an electrochemical advanced oxidation process, for the removal of the target compound diclofenac (DCF) in different water matrices. The reduction of DCF, and at the same time the formation of transformation products (TPs) and inorganic by-products, was investigated as a function of electrode settings and the duration of treatment. Kinetic assessments of DCF and possible TPs derived from data from the literature were performed, based on a serial chromatographic separation with reversed-phase liquid chromatographyfollowed by hydophilic interaction liquid chromatography (RPLC-HILIC system) coupled to ESI-TOF mass spectrometry. The application of the BDD electrode resulted in the complete removal of DCF in deionized water, drinking water and wastewater effluents spiked with DCF. As a function of the applied current density, a variety of TPs appeared, including early stage products, structures after ring opening and highly oxidized small molecules. Both the complexity of the water matrix and the electrode settings had a noticeable influence on the treatment process’s efficacy. In order to achieve effective removal of the target compound under economic conditions, and at the same time minimize by-product formation, it is recommended to operate the electrode at a moderate current density and reduce the extent of the treatment.

Reuse of Homogeneous Fenton’s Sludge from Detergent Industry as Fenton’s Catalyst

2013 ◽  
Vol 16 (2) ◽  
Author(s):  
André F. Rossi ◽  
Rui C. Martins ◽  
Rosa M. Quinta-Ferreira
Keyword(s):  
Hydrogen Peroxide ◽  
Hydroxyl Radicals ◽  
Heterogeneous Catalysts ◽  
Advanced Oxidation Process ◽  
Oxidation Process ◽  
Iron Catalyst ◽  
Advanced Oxidation ◽  
Detergent Industry ◽  
Oxidizing Agent ◽  
Fenton’S Reaction

AbstractFenton’s reaction is an advanced oxidation process where, classically, hydrogen peroxide is the oxidizing agent and an iron catalyst promotes the formation of hydroxyl radicals (•OH). Among the studies that evaluated different metals as Fenton-like catalysts, our group of investigation has recently used cerium-based solids as heterogeneous catalysts in slurry reaction and, in this work, iron sludge coming from an industrial Fenton’s reactor used for the wastewater depuration of a detergent production factory is being appraised while treating a synthetic effluent containing 0.1 g.L

scholarly journals Decontamination of N95 and surgical masks using a treatment based on a continuous gas phase-Advanced Oxidation Process

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0248487
Author(s):  
Mahdiyeh Hasani ◽  
Tracey Campbell ◽  
Fan Wu ◽  
Keith Warriner
Keyword(s):  
Hydrogen Peroxide ◽  
Gas Phase ◽  
Hydroxyl Radicals ◽  
Advanced Oxidation Process ◽  
Oxidation Process ◽  
Continuous Process ◽  
Oxidative Polymerization ◽  
Advanced Oxidation ◽  
Surgical Masks ◽  
Uv C

A gas-phase Advanced Oxidation Process (gAOP) was evaluated for decontaminating N95 and surgical masks. The continuous process was based on the generation of hydroxyl-radicals via the UV-C (254 nm) photo-degradation of hydrogen peroxide and ozone. The decontamination efficacy of the gAOP was dependent on the orientation of the N95 mask passing through the gAOP unit with those positioned horizontally enabling greater exposure to hydroxyl-radicals compared to when arranged vertically. The lethality of gAOP was independent of the applied hydrogen peroxide concentration (2–6% v/v) but was significantly (P<0.05) higher when H2O2 was introduced into the unit at 40 ml/min compared to 20 ml/min. A suitable treatment for N95 masks was identified as 3% v/v hydrogen peroxide delivered into the gAOP reactor at 40 ml/min with continuous introduction of ozone gas and a UV-C dose of 113 mJ/cm2 (30 s processing time). The treatment supported >6 log CFU decrease in Geobacillus stearothermophilus endospores, > 8 log reduction of human coronavirus 229E, and no detection of Escherichia coli K12 on the interior and exterior of masks. There was no negative effect on the N95 mask fitting or particulate efficacy after 20 passes through the gAOP system. No visual changes or hydrogen peroxide residues were detected (<1 ppm) in gAOP treated masks. The optimized gAOP treatment could also support >6 log CFU reduction of endospores inoculated on the interior or exterior of surgical masks. G. stearothermophilus Apex spore strips could be applied as a biological indicator to verify the performance of gAOP treatment. Also, a chemical indicator based on the oxidative polymerization of pyrrole was found suitable for reporting the generation of hydroxyl-radicals. In conclusion, gAOP is a verifiable treatment that can be applied to decontaminate N95 and surgical masks without any negative effects on functionality.

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