U.S. EPA Contaminated Site Cleanup Information (CLU-IN)

U.S. Environmental Protection Agency
U.S. EPA Technology Innovation and Field Services Division

Search Result

Michalsen, M.M., A.S. King, J.D. Istok, F.H. Crocker, M.E. Fuller, K.H. Kucharzyk, et al.
Journal of Hazardous Materials 387:121529(2020)

A recent pilot study demonstrated successful remediation of a hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) plume by bioaugmenting groundwater with Gordonia sp. KTR9 and Pseudomonas fluorescens strain I-C cells. A cell transport test showed the strains were transported 13 m downgradient over one month. Abundances indicators genes (xplA and xenB) of KTR9 and Strain I-C approached injection well cell densities at 6 m downgradient. Gene abundances (and conservative tracer) had begun to increase at 13 m downgradient at test conclusion. Subsequent in situ push-pull tests measured RDX degradation rates in the bioaugmented wells under ambient gradient conditions. Time-series monitoring of RDX, RDX endproducts, conservative tracer, (xplA and xenB gene copy numbers, and XplA and XenB protein abundance were used to assess the efficacy of bioaugmentation and to estimate the apparent first-order RDX degradation rates during each test. A collective evaluation of redox conditions, RDX end-products, varied RDX degradation kinetics, and biomarkers indicated that Strain I-C and KTR9 rapidly degraded RDX. Results showed bioaugmentation was a viable technology to accelerate RDX cleanup and may apply to other sites. Full-scale implementation considerations are discussed.

The Technology Innovation News Survey welcomes your comments and suggestions, as well as information about errors for correction. Please contact Michael Adam of the U.S. EPA Office of Superfund Remediation and Technology Innovation at or (703) 603-9915 with any comments, suggestions, or corrections.

Mention of non-EPA documents, presentations, or papers does not constitute a U.S. EPA endorsement of their contents, only an acknowledgment that they exist and may be relevant to the Technology Innovation News Survey audience.