History of the diverse bioaugmentation culture WBC-2: 20+ years of applications, from chlorinated solvents to PFAS

Abstract

Enhancing anaerobic biodegradation, including through reductive dehalogenation of chlorinated solvents, is a favored bioremediation application for contaminated aquifers and sediments. Biodegradation of recalcitrant halogenated compounds is a complex microbial symbiotic relationship where a variety of microbial species may facilitate different degradation steps, ferment carbon substrates, and/or provide other necessary biological components such as corrinoids. Over 20 years ago, we derived an anaerobic culture called WBC-2 (offered commercially under the KB-1 Plus family of bioaugmentation cultures) from freshwater wetland sediments, specifically to degrade the chlorinated ethane 1,1,2,2-tetrachloroethane (TeCA) and its chlorinated ethane and ethene degradation products. The source of the sediment and the enrichment method resulted in a highly diverse culture with multiple halorespirers, sulfate-reducers, and methanogens. The biodiversity of the WBC-2 culture has been shown to degrade a wide range of recalcitrant compounds and applied at sites for the remediation of TeCA, trichloroethylene (TCE), chlorobenzenes, polychlorinated biphenyls (PCBs), and the explosives compound RDX. Additional research has also shown that WBC-2 has the capability to degrade perfluorooctanesulfonate (PFOS). The history of research and application of WBC-2 will be illustrated through laboratory and field case studies, culminating in ongoing research on biodegradation of per- and polyfluoroalkyl substances (PFAS) and implications for bioremediation.

Collaboration with SIREM is important in this history, from growing WBC-2 to large quantities at the beginning and then maintaining and offering WBC-2 as part of the KB-1 Plus family of commercially available bioaugmentation cultures.

The Presenters

Michelle M. Lorah, Ph.D.Research Hydrologist, U.S Geological Survey
Dr. Lorah is a Research Hydrologist with the U.S. Geological Survey in the Maryland-Delaware-DC Water Science Center where she leads the Fate and Bioremediation Team. Michelle has a central role in PFAS research at the USGS as a co-lead for the national PFAS Integrated Science Team under the Environmental Health Program. Michelle has extensive experience in studying biodegradation processes, determining environmental factors controlling fate of contaminants in different environments, and developing bioremediation technologies. She received a Ph.D. in Environmental Chemistry through the Marine-Estuarine-Environmental Sciences Program at the University of Maryland, M.S. in Environmental Science from the University of Virginia, and B.S. in Geosciences with a minor in Marine Science from Penn State.
Portrait of Corey Scales
Corey Scales, B.Sc.Bioaugmentation Production Manager, SiREM
Corey has technical experience in the growth, scale-up, and field implementation of several anaerobic microbial bioaugmentation cultures to degrade contaminants including chlorinated solvents, petroleum hydrocarbons, and other recalcitrant compounds. Over the past seven years, he has provided technical support throughout the planning, injection, post-injection monitoring and data analysis stages for hundreds of field bioaugmentation events. He is focused on providing customer support and insights to optimize bioremediation success.