Understanding the impact of the scavenging capacity on costs of the UV chlorine advanced oxidation process for drinking water treatment using the external calibration method and the development of cost curves.

UV-driven advanced oxidation processes (e.g. UV/H2O2, UV/Cl) that couple UV irradiation with oxidizing chemicals to generate highly reactive species such as ·OH radicals and reactive chlorine species are increasingly being recommended for the removal of recalcitrant organic contaminants in drinking water and wastewater. Establishing the doses of UV and oxidant required to achieve treatment objectives is challenging because many species besides the contaminant(s) of interest exert a scavenging capacity for the highly reactive species generated in advanced oxidation processes. Overall, the aim of this research was to establish whether a colour-based test developed to measure the hydroxyl radical scavenging capacity of water samples could be adapted to measure the scavenging capacity of reactive chlorine species in addition to hydroxyl radicals. The results were used to estimate the cost implications of installing a UV/H2O2 or UV/Cl reactor in a drinking water treatment plant. Initial capital and ongoing operational and maintenance cost curves were developed to characterize the potential cost savings of utilizing the method to treat a well-known contaminant of concern.