Determination of Reaction Rate Constants in a Collimated Beam Setup: The Effect of Water Quality and Water Depth

UV/H2O2 processes can be studied using a Collimated Beam (CB) setup. In UV dose calculations, the "water factor" accounts for changes in the irradiation spectrum upon its way through the aqueous solution. Analogous to the "germicidal factor," the "extinction factor" is introduced, correcting for the fact that resulting compounds will be subjected to an emission spectrum changing over the depth. Using the extinction factor, the fluence-based photolysis and oxidation rate constants of model compounds, as well as the quantum yield for nitrite formation, were found to be independent of the depth of the water layer applied.