Light-driven breakdown of 1,4-Dioxane for potable reuse: A review

Increasing fresh water scarcity has forced some countries to adopt potable water reuse. Membrane-based techniques, represented by microfiltration (MF) and reverse osmosis (RO), have shown considerable potential to that end, but they are still not able to filter some micropollutants. Among these species, the compound 1,4-Dioxane has received an increasing attention in recent years since it is used as a common industrial solvent and a solvent stabilizer, and has the potential to be carcinogenic to humans when in potable water. Photolytic and photocatalytic advanced oxidation processes driven by UV or solar light, including TiO₂-, Fenton-like-, copper-, peroxide-, ozone- and chloramine-based methods, have been developed in the past decades to decompose 1,4-Dioxane in contaminated waters. The current work presents recent understandings on the nature of 1,4-Dioxane, identification methods and an updated overview on the photolytic and photocatalytic techniques applied to 1,4-Dioxane removal. In particular, the mechanisms and kinetics involved in the photo(cata)lytic oxidation of 1,4-Dioxane are also reviewed, and new trends in application of these approaches for potable reuse is discussed in detail.