Envirogen to test new treatment for 1,4-Dioxane, cVOCs in groundwater

Envirogen Technologies Inc. announced that it been awarded a $900,000 contract to test a novel biological treatment, using a fluidized bed reactor (FBR), for groundwater contaminated by 1,4-Dioxane (1,4-D) and dilute levels of chlorinated volatile organic compounds (cVOCs).

The contract was awarded by the Environmental Security Technology Certification Program (ESTCP) through the U.S. Army Corp of Engineers.

The R&D-based project will study the use of a butane degrading microbe in an FBR to consume isobutane and cometabolically treat 1,4-D and the cVOCs. The three-year project, which began in the fourth quarter of 2022, comprises bench-scale testing in New Jersey followed by a pilot-scale off-site demonstration in Tennessee estimated to begin in 2024 or 2025.

For Estcp Press Release Fbr Pilot2 High Res

“The butanotroph microbe-based treatment approach is novel because it’s the first time it will have been tested to remove these co-contaminants from groundwater in an ex-situ bioreactor,” says Todd Webster, vice president of Envirogen Technologies. “The project’s overall objective is to demonstrate and validate the use, performance and costing of an FBR, using the butane degrading microbe for the treatment of the comingled contaminants.”

DoD remediation plan

The project is part of the Department of Defense (DoD) remediation plan for the cleanup of water contaminated by 1,4-D and other recalcitrant chemicals. The DoD has used cVOCs as degreasing agents and cleaning agents for years, with 1,4-D added as a chlorinated solvent stabilizer, resulting in these chemicals contaminating groundwater at DoD sites. Historically, at such sites, cVOCs are treated by air stripping, followed by carbon or advanced oxidation processes (AOP) such as UV light-hydrogen peroxide or ozone-hydrogen peroxide to treat the 1,4-D.

“Multiple treatment processes of air stripping and AOP are the traditional means to remove these co-contaminants from groundwater," says Webster states. "Although these technologies are effective, they can also be expensive because of the necessary capital and electricity requirements. Our novel use of a single biological technology to treat both 1,4-D and dilute cVOCs in groundwater would provide improved life-cycle treatment costs for the DoD at numerous contaminated sites.”

Current data suggest that a biological system to treat these co-contaminant streams to required regulatory levels is potentially both feasible and sustainable. Envirogen’s FBR is a fixed-film bioreactor in which a high concentration of naturally occurring biomass containing the butanotroph microbe is attached to a fluidized medium. Biological treatment of the contaminated water occurs within that biomass-medium interface.

Envirogen has partnered with APTIM Federal Services, a subcontractor in this project, to collaborate on the bench-scale element work. APTIM specializes in critical infrastructure, technical and data solutions, and related services including environmental remediation.