Case Study and Retrospective: Aerobic Fixed Film Biological Treatment Process for 1,4-Dioxane at the Lowry Landfill Superfund Site

摘要

An aerobic fixed film biological treatment system has been successfully treating recovered groundwater/ landfill leachate containing 1,4-dioxane, tetrahydrofuran (THF), and other constituents since 2003. The most likely mode of 1,4-dioxane biotransformation is via a cometabolic pathway in the presence of THF. Pilot studies conducted during the process development phase established a design basis process loading factor of 0.6 g 1,4-dioxane and THF (as chemical oxygen demand [COD])/g total solids per day and proved the efficacy of the process. Full-scale design includes the use of three parallel moving bed bioreactors with effluent recycle capability. Removal efficiencies in excess of 98 percent have been documented for 1,4-dioxane. Evolving operational challenges are associated with recent trends in 1,4-dioxane pretreatment discharge limitations in combination with ongoing process optimization and increased influent flow rate conditions associated with seasonal precipitation patterns.