Cometabolic Treatment of 1,4-Dioxane in Biologically Active Carbon Filtration with Tetrahydrofuran and Propane at Relevant Concentrations for Potable Reuse

High Resolution Image Download MS PowerPoint Slide 1,4-Dioxane is a probable human carcinogen and a widely occurring water contaminant. Cometabolic biodegradation of 1,4-dioxane could potentially provide a cost-effective and efficient treatment, but research is needed to establish its viability for water reuse purposes. The purpose of this study was to compare propane versus tetrahydrofuran as cometabolites for enhancing the removal of 1,4-dioxane via biologically active carbon filtration (BAF) as part of a pilot-scale water reuse system. Removal of 10, 5, 1, and 0.3 μg/L of 1,4-dioxane by BAF was examined in systems amended with either propane (2 mg/L) or tetrahydrofuran (25–50 μg/L), receiving the same ozonated, secondary wastewater effluent. At the lowest influent 1,4-dioxane concentration (0.3 μg/L), the tetrahydrofuran amended filter removed on average 58% ± 4% (std dev) of the incoming 1,4-dioxane. During the same period, the propane amended filter removed on average 74% ± 7% of the incoming 1,4-dioxane and at times degraded the 1,4-dioxane to below the method detection limit of 0.06 μg/L. This study demonstrates that amending cometabolites prior to BAF is a feasible treatment technique for removal of 1,4-dioxane occurring at submicrogram per liter concentrations and thus holds promise for both potable reuse applications and drinking water treatment.