Impact of groundwater quality and associated byproduct formation during UV/hydrogen peroxide treatment of 1,4-dioxane

In this study, a semi-batch, bench-scale UV/hydrogen peroxide (UV/H2O2) advanced oxidation process system was used to investigate how typical groundwater quality parameters (pH, alkalinity, natural organic matter (NOM), nitrate, and iron) influence the treatment of 1,4-dioxane. Deionized (DI) water spiked with 1,4-dioxane (100 μg L−1), treated using H2O2 (10 mg L−1) in a commercially available UV system (40 W low-pressure lamp) showed an UV fluence-based first-order rate constant (k’) and electrical energy-per-order (EEO) of 4.32✕10−3 cm2-mJ−1 and 0.15 kWh-m−3-order−1, respectively. The most abundant byproduct generated in spiked-DI water was oxalic acid (up to 55 μg L−1), followed by formic and acetic acids. The k’ showed no significant difference at pH ranging from 5 to 7 and at low alkalinity concentrations (