About the OH yield in the radiolysis of an aqueous/H2O2 system. Its optimisation for water treatment

Unless the radiolytic reducing species are neutralised or converted into oxidising species, an EB remediation system cannot be considered a true Advanced Oxidation Processes (AOP). A water/H2O2 system irradiated by UVC mercury lamps constitutes a widely used OH production method. Employing H2O2 in radiolysis as well, an enhancement of the oxidative efficiency of an EB treatment can be obtained. Pulse radiolysis measurements of an aerated aqueous/H2O2/KSCN system have been systematically undertaken to assess the optimal H2O2 concentration. By linearly fitting a competition kinetics relationship, it is found that the scavengeable extra-yield of OH is Delta G(OH)=0.24 mu mol J(-1) (R=0,9958), while the maximum experimental yield is measured G(OH)(max)=(0.52 +/- 0.02) mu mol J(-1) when [H2O2]=5-10 mM. Exceeding these concentrations the OH yield drops off. Published by Elsevier Ltd.