D reactor building

Field Investigations of Lactate-Stimulated Bioreduction of Cr(VI) to Cr(III) at Hanford 100H. The objective of this project is to perform field investigations to assess the potential for immobilizing and detoxifying chromium contaminated soils and groundwater using bioremediation at Site 100H at Hanford.

Hypothesis: Lactate (HRC) injection into chromium-contaminated groundwater through an injection well will cause bioreduction of chromate [Cr(VI)] and precipitation of insoluble species of [Cr(III)] on soil particles, probably catalyzed at oxide surfaces at the field scale.

The objective of this project is to perform field investigations to assess the potential for immobilizing and detoxifying chromium contaminated soils and groundwater using bioremediation at Site 100H at Hanford.

Specific goals include:

Designing a field test to measure the effect of lactate biostimulation on microbial community activity, redox gradients, transport limitations, and other reducing agents in comparison with our previous NABIR laboratory work. Establishing the rates and conditions that may cause reoxidation of Cr(III) to Cr(VI) following biostimulation Assessing the use of bioremediation in conjunction with alternative remediation technologies Providing design criteria for full-scale deployment on in situ Cr(VI) bioreduction via lactate stimulation for use at DOE sites.

LBNL PIs:
Terry Hazen
Boris Faybishenko
Tetsu Tokunaga
Jiamin Wan
Susan Hubbard
Mary Firestone

LBNL Collaborators:
Mark Conrad
Ken Williams

Regenesis:
Steve Koenigsberg
Anna Willett

Pacific Northwest National Lab:
Phil Long