Converting Contaminated Aquifers into Purifying Filters: Colloidal Activated Carbon

Tuesday, August 8, 2017: 9:30 a.m.
Jeremy Birnstingl, Ph.D. , Regenesis, San Clemente, CA
Kristen Thoreson, Ph.D , Research & Development, REGENESIS, San Clemente, CA
Scott Wilson , REGENESIS, San Clemente, CA
Craig Sandefur , Technical Services, REGENESIS, San Clemente, CA

Legacy groundwater plumes of halogenated organic solvent contaminants are often large and diffuse. In situ treatment of these plumes is often considered infeasible due largely to the long term back-diffusion of contaminants from lower permeability matrices within heterogeneous aquifers systems.

Recent innovations in dispersion chemistry has resulted in the development of a highly sorbent, colloidal activated carbon which has been demonstrated to flow easily into aquifer matrices. Once distributed in the subsurface, the colloidal material will permanently deposit to form a coating on the aquifer matrix while leaving groundwater flow unrestricted. Dissolved contaminants rapidly sorb into the activated carbon and are stripped from groundwater fluxing through the treated zone or back-diffusing from lower permeability zones. Biodegradation of the contaminants concentrated upon the carbon layer is accelerated by the use of dispersion chemistry that serves as long term electron donor and the option of bioaugmenting with contaminant-degrading microbial consortia (e.g. DHC).

Data is presented from a dual-porosity tank study conducted at Colorado State University which supports the hypothesis that colloidal activated carbon, when applied in high flux zones, is highly effective at the long-term treatment of back-diffusion. Key data from this study includes the observation of limited daughter product formation in conjunction with Dehalococcoides populations that are two orders of magnitude higher in the presence of the colloidal activated carbon than without. Additional data is also included on the ability of the colloidal carbon to migrate throughout both the transmissive and the lower permeability soil layers.

Results of pilot-scale and full-scale commercial remediation projects are also presented which indicate that colloidal activated carbon may be an effective solution in treating back-diffusing legacy plumes. Technical hurdles to success are described and future development plans are discussed.

Jeremy Birnstingl, Ph.D., Regenesis, San Clemente, CA

Kristen Thoreson, Ph.D, Research & Development, REGENESIS, San Clemente, CA
Dr. Kristen Thoreson leads the chemical research and product development program at REGENESIS. She is trained as a chemist, and her graduate and post-doctorate research focused on mechanistic investigations of chlorinated ethene degradation pathways using molecular models and compound specific isotope analysis (CSIA) for both biotic and abiotic systems. She obtained her BSc in chemistry from the University of Wisconsin – La Crosse, and her PhD in inorganic chemistry from the University of Minnesota. She also spent time as a postdoctoral associate at the Helmholtz Zentrum in Munich, Germany as a part of the Research Unit for Environmental Organic Isotope Chemistry.

Scott Wilson, REGENESIS, San Clemente, CA
Scott Wilson is CEO of REGENESIS, a global leader in the development of technologies for the restoration of contaminated land. Patented technologies developed by REGENESIS have been used in the restoration of over 18,000 environmental project sites worldwide. The majority of Mr. Wilson’s 30 year career has focused on technology development/commercialization activities in the fields of microbial enhanced oil recovery, industrial wastewater, and environmental remediation. Prior to joining REGENESIS he held the position of Vice President of Remediation Technology at Groundwater Technology, Inc. where he was responsible for technology development and transfer throughout the global organization. For nearly a decade Mr. Wilson lectured on behalf of the National Water Well Association (now NGWA) on the topic of groundwater remediation. He remains a frequent contributor to conferences/symposia on topics related to innovative technologies. Mr. Wilson holds a M.S. in Applied Microbiology (related to geochemistry/petroleum engineering) from University Texas at El Paso, and a MBA from the Kellogg School at Northwestern University.

Craig Sandefur, Technical Services, REGENESIS, San Clemente, CA
Craig Sandefur is Vice President of Technical Services for REGENESIS and is recognized as an expert in the field of aerobic and anaerobic bioremediation. He has over 17 years of experience in the remediation industry and has developed much of REGENESIS’ current product application capabilities. In this role, Mr. Sandefur was the focal point in the development of what is now commonly accepted direct-push application protocols for delivery of electron acceptors like ORC® and ORC Advanced®, electron donors like HRC® and 3-D Microemulsion (3DME)® and chemical oxidants like RegenOx®. Mr. Sandefur has successfully designed and implemented a wide-range of in situ remediation strategies on hundreds of projects worldwide. He received his BSc. in Biology from Southwestern Union College in Keene, TX and his MSc. in Geology from Loma Linda University in Riverside, CA.