A New Method for the Measurement of Low Concentrations of OH/O2- Radical Species in Water by High-LET Pulse Radiolysis. A Time-Resolved Chemiluminescence Study

Comparative study of luminescence and chemiluminescence in hydrodynamic cavitating flows and quantitative determination of hydroxyl radicals production

Luminescence and chemiluminescence have been experimentally investigated in hydrodynamic cavitating flows. By using dedicated microdevices inserted inside a light tight box, photons counting has been made possible. Luminescence has been investigated with deionized water as the working fluid; chemiluminescence has resulted from cavitating alkaline luminol solutions, and has been correlated to hydroxyl radicals formation. For the first time, luminescent and chemiluminescent phenomena have been considered together on the same devices submitted to similar cavitating flow regimes. Degassed solutions enhance the luminescence and also the hydroxyl radical yield. Due to the small sizes of the channels, the lifetimes of the collapsing bubbles correspond to pseudo frequencies matching the range of optimal frequencies used in sonochemistry. New perspectives for the study of hydrodynamic cavitation as an advanced oxidation process are suggested.

Revisited water radiolysis at elevated pH by accounting O3˙− kinetics at low and high LET

Recordings of O₃˙⁻ formation and decays under low and high LET radiations and at pH 13.2 allowed revisiting the rate constants of its reactions with O₂˙⁻ and HO₂⁻.

Détection des radicaux OH et O–2 issus de la radiolyse de l'eau par chimiluminescence résolue en temps

A new method for the detection of low concentrations of hydroxyl and superoxide radicals, formed by water radiolysis, is described in this article. The method used is the time resolved chemiluminescence. It has been performed with an electron beam delivered by a Febetron 707 accelerator. This method allows to measure hydroxyl and superoxide radical concentrations in a large range of concentrations, between 10–5 and 10–8 M.Key words: chemiluminescence, pulse radiolysis, hydroxyl radical, superoxyde radical.[Traduit par la Rédaction]