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

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).

2004 ◽  
Vol 49 (4) ◽  
pp. 207-212 ◽  
Author(s):  
I. Tröster ◽  
L. Schäfer ◽  
M. Fryda ◽  
T. Matthée

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.


Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 521
Author(s):  
Fernando J. Beltrán ◽  
Ana Rey ◽  
Olga Gimeno

Formation of disinfection byproducts (DBPs) in drinking water treatment (DWT) as a result of pathogen removal has always been an issue of special attention in the preparation of safe water. DBPs are formed by the action of oxidant-disinfectant chemicals, mainly chlorine derivatives (chlorine, hypochlorous acid, chloramines, etc.), that react with natural organic matter (NOM), mainly humic substances. DBPs are usually refractory to oxidation, mainly due to the presence of halogen compounds so that advanced oxidation processes (AOPs) are a recommended option to deal with their removal. In this work, the application of catalytic ozonation processes (with and without the simultaneous presence of radiation), moderately recent AOPs, for the removal of humic substances (NOM), also called DBPs precursors, and DBPs themselves is reviewed. First, a short history about the use of disinfectants in DWT, DBPs formation discovery and alternative oxidants used is presented. Then, sections are dedicated to conventional AOPs applied to remove DBPs and their precursors to finalize with the description of principal research achievements found in the literature about application of catalytic ozonation processes. In this sense, aspects such as operating conditions, reactors used, radiation sources applied in their case, kinetics and mechanisms are reviewed.


2019 ◽  
Vol 5 (11) ◽  
pp. 1985-1992 ◽  
Author(s):  
Nor Elhouda Chadi ◽  
Slimane Merouani ◽  
Oualid Hamdaoui ◽  
Mohammed Bouhelassa ◽  
Muthupandian Ashokkumar

We have recently reported that the reaction of H2O2/IO4− could be a new advanced oxidation process for water treatment [N. E. Chadi, S. Merouani, O. Hamdaoui, M. Bouhelassa and M. Ashokkumar, Environ. Sci.: Water Res. Technol., 2019, 5, 1113–1123].


Author(s):  
André F. Rossi ◽  
Rui C. Martins ◽  
Rosa M. Quinta-Ferreira

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


2018 ◽  
Vol 4 (10) ◽  
pp. 1389-1411 ◽  
Author(s):  
Moses G. Peleyeju ◽  
Omotayo A. Arotiba

Electrochemical advanced oxidation process and heterogeneous photocatalysis have received great attention in the last few years as alternative/complementary water treatment technologies.


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