Removal of 1,4-Dioxane from Wastewater by Copper Oxide Catalyzed WAO with Mild Condition

Abstract

1,4-Dioxane is a contaminant of emerging concern that is classified by the U.S. Environmental Protection Agency as a likely human carcinogen. Moreover, 1,4-dioxane easily migrates to groundwater due to its high solubility in water and hard to be biodegraded or removed by traditional water treatment technology. Therefore, it is indispensable to develop new methods and technologies to dispose of 1,4-dioxane in the wastewater. Herein, this study presented catalytic wet air oxidation (CWAO) with CuO as a catalyst and O2 as an oxidant to treat 1,4-dioxane and investigated the influence of reaction conditions, including temperature, reaction time, oxygen content, catalyst addition and pH, on the degradation of 1,4-dioxane. The highest degradation rate (R) of 1,4-dioxane was 95.8 % when the optimal reaction conditions were at 200 °C and 1 MPa O2 for 60 min with 5 mmol CuO added. If the effect of Cu2+ dissolution was not considered, the R of 1,4-dioxane is up to 99.8 % was achieved at an acidic condition (pH=3) with 2 mmol CuO added.