Presented May 23, 2019- Presentation Slides
“Reactive Gas Process for In Situ Treatment of 1,2,3-Trichloropropane (TCP) in Vadose Zone Soils” by Dr. Paul Hatzinger
The objective of this ESTCP-funded research project was to demonstrate a novel reactive gas process for remediation of vadose zone source areas containing 1,2,3-trichloropropane (TCP), an emerging contaminant that is present at sites through its application as a solvent as well as its presence in specific soil fumigants. The reactive gas process involves the injection of a blend of air and gaseous ammonia (NH3) to raise soil pH and promote alkaline hydrolysis of TCP and other susceptible chemicals of concern (COCs). The process may also stimulate cometabolic biodegradation reactions mediated by the enzyme ammonia monooxygenase. A field demonstration is currently being planned at a former pesticide manufacturing and mixing facility in the Central Valley of California. Laboratory treatability studies suggest that the process can be a viable approach for increasing soil pH and enhancing the alkaline hydrolysis of TCP and other COCs at this site in a cost-effective manner. This project is expected to provide DoD with a new approach to remediate vadose areas that contain TCP, as well as common explosives and other contaminants susceptible to alkaline hydrolysis.
“Natural Attenuation and In Situ Treatment of 1,2-Dibromoethane (EDB) at a Complex Field Site” by Dr. Paul Koster van Groos
1,2-Dibromoethane (EDB) was added to almost every leaded fuel and is now an emerging contaminant. While it degrades under both aerobic and anaerobic conditions, EDB has been observed above its low maximum contaminant level (MCL) of 0.05 µg/L decades after leaded fuels were last used at sites. During this work, EDB natural attenuation was evaluated at a complex field site using many tools, including examination of daughter products and compound-specific isotope analysis (CSIA). In higher concentration anaerobic zones at the site, the presence of ethene suggested that anaerobic debromination of EDB occurred, while in more dilute areas, EDB enriched in 13C indicated slower degradation consistent with abiotic hydrolysis. Laboratory studies were performed to quantify isotope enrichment to support this CSIA interpretation. During this work, anaerobic biostimulation was also demonstrated to enhance EDB degradation in the field together with enrichment of 13C in EDB. Overall, these results help provide more tools for assessing the natural attenuation of EDB and indicate that an in-situ treatment used for chlorinated volatile organic compounds may be useful for treating higher concentrations of EDB.
Dr. Paul Hatzinger is the Director of the Biotechnology Development and Applications Group at APTIM Federal Services in Lawrenceville, New Jersey. He is a broadly trained environmental scientist with expertise in groundwater microbiology and geochemistry, bioremediation, and stable isotope analysis. His current areas of research include the development of in situ and ex situ remediation strategies for emerging DoD groundwater contaminants, including 1,2,3-trichloropropane, 1,4-dioxane, traditional and insensitive munitions constituents, n-nitrosodimethylamine (NDMA), and 1,2- dibromoethane. Paul holds a Bachelor of Science degree in Biology and Environmental Science from St. Lawrence University and both a Master of Science and doctoral degreesin Environmental Toxicology from Cornell University.
Dr. Paul Koster van Groos is a research scientist at APTIM Federal Services in Lawrenceville, New Jersey. His research focuses on quantifying environmental processes with respect to natural attenuation, remediation, and forensics, and on developing novel in situ and ex situ treatment technologies. Since joining APTIM, Paul’s work has included a focus on emerging contaminants such as 1,2‑dibromoethane, 1,4 dioxane, and per- and polyfluoroalkyl substances (PFAS). At APTIM and previously, Paul has also worked to advance the use of isotope tools to better understand contaminant sources and fate. He earned a bachelor’s degree in civil and environmental engineering from Cornell University in Ithaca, New York, a master’s degree in environmental engineering from the University of Michigan in Ann Arbor, and a doctorale degree in environmental engineering from the University of California, Berkeley.