CE Seminar: Optimization-based monitoring of a fluidized bed biofilm reactor at the 200 West Area Pump and Treat Facility at the Hanford Site

Optimization-based monitoring of a fluidized bed biofilm reactor at the 200 West Area Pump and Treat Facility at the Hanford Site
Presented By: Dr. Hope Lee, Environmental System Group-Pacific Northwest National Laboratory

Abstract:
Contaminated groundwater beneath the 200 West Area at the Hanford Site in southeastern Washington state is currently being treated using a pump-and-treat system to remove organics, inorganics, radionuclides, and metals. A granular activated carbon-based fluidized bed bioreactor (FBBR) has been added to remove nitrate, hexavalent chromium, and carbon tetrachloride. Initial analytical results indicated the microorganisms reduced many of the contaminants to less than cleanup levels. However, shortly thereafter, the FBR experienced operational upsets, including carbon carry over, over production of microbial extracellular polymeric substance (biofilm) materials, and over production of hydrogen sulfide. As a result, detailed investigations were undertaken to understand the functional diversity and activity of the microbial community in the FBBR over time. Molecular analyses were performed on the microbial community extracted from the biofilm within the bed and from the inoculum, to determine functional dynamics of the FBBR bed over time and following operational changes. Results indicated that molecular tools can be powerful for determining functional diversity within FBBR-type reactors. Coupled with micronutrient, influent, and effluent chemistry evaluations, a more complete understanding of the balance between system additions (nutrients, groundwater) and biology can be achieved, increasing long-term predictions of performance. These analyses uniquely provide information that can be used to optimize the overall performance, efficiency, and stability of the system both in real time and over the long-term, as the system design is altered or improved and/or new streams are added.

Bio
Dr. Hope Lee is formally trained in environmental microbiology and oceanography.  Hope has experience in management and technical oversight of multiple DOE and DoD projects, specializing in the development and validation of microbial characterization and monitoring tools for use in environmental remediation. During the past 15 years, Hope has been involved on numerous multi-agency teams focused on the characterization, performance evaluation, and optimization of remedial strategies at contaminated sites. Hope is currently the technical lead and manager of the Soil and Groundwater Program at PNNL.