Degradation of N-nitrosamines and 1,4-dioxane using vacuum ultraviolet irradiation (UV254+185 nm or UV172 nm)

Advanced oxidation processes (AOPs) play a vital role in attenuating contaminants of emerging concern (CECs) during potable water reuse. AOPs are conventionally performed by irradiating with 254-nm low-pressure (LP) mercury-vapor (Hg) ultraviolet (UV) lamp along chemical treatment. Compared UV-C light treatment (200–280 nm), vacuum-UV (V-UV) (100–200 nm) is advantageous terms hydroxyl radical generation without the requirement for This study assessed potential V-UV (172-nm Xe2 excimer or 185 + LP-Hg) lamps on destruction two major CECs reuse, namely N-nitrosodimethylamine (NDMA) and 1,4-dioxane. Direct irradiation using UV254 nm UV185+254 achieved ≥94% removal N-nitrosamines, including NDMA, at UV dose 900 mJ/cm2. In contrast, (UV172 was less effective N-nitrosamine removal, achieving up to 82% NDMA. The 1,4-dioxane mJ/cm2 reached 51% 28% (UV185+254 both which results were superior that obtained conventional (10%). addition hydrogen peroxide found enhance 1,4-dioxane, while UV172 still exhibited greater efficiencies than those lamps-based AOPs. Overall, this demonstrated NDMA can be successfully either UV254+185 peroxide.