Electrochemical generation of ozone for water treatment using a cell operating under natural convection

Direct And Mediated Anodic Oxidation of Organic Pollutants

“…The electrochemical ozone generation reaction at the anode can be expressed as Ozone production efficiency is limited by oxygen evolution occurring at lower potential and it is, therefore, thermodynamically favored: In order to obtain the best EOP efficiency, literature reports suggest using electrode materials having high oxygen overpotential and performing electrolysis at low temperature, very low interfacial pH, and high anodic current. As a result, most of the investigations have focused on the use of lead dioxide; 47,140,[315][316][317][318][319][320][321][322][323][324][325][326] however, tin dioxide, 327,328 Ti/ IrO 2 -Nb 2 O 5 , 329 Ti/IrO 2 -Ta 2 O 5 , 330 platinum, 331,332 glassy carbon, 333 and diamond [334][335][336] were also studied.…”

“…In order to obtain the best EOP efficiency, literature reports suggest using electrode materials having high oxygen overpotential and performing electrolysis at low temperature, very low interfacial pH, and high anodic current. As a result, most of the investigations have focused on the use of lead dioxide; ,,− however, tin dioxide, , Ti/IrO 2 −Nb 2 O 5 , Ti/IrO 2 −Ta 2 O 5 , platinum, , glassy carbon, and diamond − were also studied.…”

Electrochemical oxidation for landfill leachate treatment

“…4: indirect oxidation, where a mediator is electrochemically generated to carry out the oxidation, and direct anodic oxidation, where pollutants are destroyed on the anode surface (Grimm et al, 1998). During indirect oxidation, the agents generated anodically, which are responsible for oxidation of inorganic and organic pollutants, may be chlorine and hypochlorite (Naumczyk et al, 1996;Vlyssides et al, 1997), hydrogen peroxide (Brillas et al, 1995(Brillas et al, , 1996, ozone (Stucki et al, 1987;El-Shal et al, 1994), and metal mediators such as Ag 2+ (Farmer et al, 1992). Furthermore, hydroxyl radicals can also be generated to enhance oxidation through electro-Fenton reactions where added ferrous ion reacts with electrochemically generated hydrogen peroxide (Matsue et al, 1981;Brillas et al, 1996).…”

Electrochemical oxidation of organic pollutants for the wastewater treatment: direct and indirect processes

“…177 As far as other chemical agents are concerned, several pollutants can be degraded by electrochemically generated hydrogen peroxide, [178][179][180][181][182][183] and electrically generated ozone is reported for wastewater treatment too. 184,185 The anodic oxidation of organics in the presence of NaBr was studied in the case of isosorbide, 16 methyl-orange, 17 hydrazo-dicarbonamine 18 and lactic acid; 19 NaBr was also employed as a mediator for the indirect oxidation of alcohols, in a double mediator system. 20 Fig.…”