AWWA WQTC65849

Several approaches for modeling UV/H₂O₂ Advanced Oxidation Processes (AOPs) exist, including the steady state hydroxyl radical (OH) radical method (Glaze et al, 1995) as well as the commercially available AdOx method (Crittenden et al, 1999). While these approaches perform decently in approximating chemical destruction for the UV/H₂O₂ AOPs, they rely on theoretical assumptions for rate constants to determine the amount of OH radical mediated oxidation. Problems arise because simplifications, such as using a universal rate constant for dissolved organic carbon as a surrogate for natural organic matter (NOM), are utilized in these models. The R_OH,UV concept, defined as the experimentally determined OH radical exposure per UV Fluence for a given water matrix and [H₂O₂]i, can characterize the effectiveness of UV/H₂O₂ AOP within a specific water matrix. The probe compound utilized to investigate the R_OH,UV concept is para-Chlorobenzoic Acid (pCBA), and was chosen due to the widespread use of this compound to characterize other AOPs (Elovitz and von Gunten 1999, Pines and Reckhow 2003, and Han et al, 2002). R_OH,UV is developed similar to the R_Ct concept (Elovitz and von Gunten, 1999) used in ozone studies, and a full derivation of the concept can be found in Rosenfeldt and Linden, 2007). The R_OH,UV provides insight about the effectiveness of advanced oxidation in a water matrix, and can be utilized to model the destruction of micropollutants of concern in the water. Includes 9 references, table, figure.