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

This study investigated a cometabolicapproach to removing1,4-dioxane, a carcinogenic water contaminant, using biologicallyactive carbon filtration for water reuse purposes. 1,4-Dioxane is aprobable human carcinogen and a widely occurringwater contaminant. Cometabolic biodegradation of 1,4-dioxane couldpotentially provide a cost-effective and efficient treatment, butresearch is needed to establish its viability for water reuse purposes.The purpose of this study was to compare propane versus tetrahydrofuranas cometabolites for enhancing the removal of 1,4-dioxane via biologicallyactive carbon filtration (BAF) as part of a pilot-scale water reusesystem. Removal of 10, 5, 1, and 0.3 & mu;g/L of 1,4-dioxane byBAF was examined in systems amended with either propane (2 mg/L) ortetrahydrofuran (25-50 & mu;g/L), receiving the same ozonated,secondary wastewater effluent. At the lowest influent 1,4-dioxaneconcentration (0.3 & mu;g/L), the tetrahydrofuran amended filterremoved on average 58% & PLUSMN; 4% (std dev) of the incoming 1,4-dioxane.During the same period, the propane amended filter removed on average74% & PLUSMN; 7% of the incoming 1,4-dioxane and at times degraded the1,4-dioxane to below the method detection limit of 0.06 & mu;g/L.This study demonstrates that amending cometabolites prior to BAF isa feasible treatment technique for removal of 1,4-dioxane occurringat submicrogram per liter concentrations and thus holds promise forboth potable reuse applications and drinking water treatment.