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Title: Bioaugmentation of an Engineered Metal Treatment Wetland with Cupriavidus SRS

Conference ·
OSTI ID:23005539
; ; ;  [1]
  1. Savannah River National Laboratory - SRNL (United States)

There are many chemical methods to remediate copper (Cu) from the environment. However, the use of microorganisms has been identified to be cheaper and more efficient in remediating toxic compounds in a method known as bioremediation. A microorganism, Cupriavidus SRS, is a metal resistant, rod shaped, gram negative bacteria that was isolated from a location with heavy metal contamination. As a predator this isolate has the ability to attack gram-negative and gram-positive bacteria. It is highly tolerant to Cu, and the isolates growth initiation is stimulated by Cu. Wang et al. (2015) determined that efflux pump activity is one of the most important mechanisms of heavy metal tolerance and the Cupriavidus genus demonstrates this behavior. In this study, Cupriavidus SRS will be inoculated to sediment and water from an area with high concentrations of Cu and zinc, to determine the ability of the isolate to grow and survive in a high level Cu wetland as well as the bioremoval efficiency. The H-02 wetland in the AL1 outfall area is an engineered wetland that was constructed to utilize natural processes associated with sediments and microbial communities to remove contaminants from waste waters at the Savannah River Site. Specifically, this wetland treats the building processes and runoff form the Tritium Processing Facility in H-area to prevent Cu and Zn from entering the water before the contaminants go in the Savannah River. Distributions of Cu and Zn follow organic matter levels with higher densities along the shoreline showing that metal concentrations correlate with organic matter content. Cupriavidus SRS Growth: Cupriavidus SRS was isolated at the Savannah River Site from an area with heavy metal contamination. Cultures were grown in R2A medium at 25 deg. C and shaken at 80 rpm for liquid cultures for 5 days. Sediment and Water Collection: All samples were collected from the AL1 Outfall area within the Department of Energy's Savannah River Site. Sediment cores, organic layer samples, and water samples were collected from the Inlet and Outlet cells in triplicate. Only water samples were collected from the basin. Cell Pellet: After centrifugation at 10,000 RPM for 10 minutes the supernatant was removed. 1 mL of phosphate buffer saline was added to the tube, vortexed, and recentrifuged. Inoculation of Sediment and Water: All samples were done in triplicate, vortexed after inoculation, and put on the shaker for 72 hours. Day 0 begins when the samples are removed from the shaker. Experimental Set-Up: All samples were done in triplicate. All sediment samples were centrifuged at 7500 RPM for 10 minutes on Day 0 and Day 5. All the sediment and water samples were filtered with a 0.2 μm nylon filters to obtain approximately 10 mL of supernatant on Day 0 and Day 3. pH was taken 24, 48, and 72 hours after the samples had been on the shaker. Plate Count: Plate counts were done on Day 0 and Day 3 to determine Cupriavidus SRS growth following a quantitative counting method from Seely et al. (1972). This project is ongoing and the goal is to determine if Cupriavidus SRS has the ability to uptake excess Cu out of the environment. These could be some possible results for the experiment: - The isolate uptakes too much Cu, dies, and releases Cu back into the environment. - The isolate is able to uptake Cu, continue to live, but chemically changes the environment introducing new problems. - The isolate is able to uptake Cu, continue to live, and does not disrupt the environment with toxic chemical changes.

Research Organization:
WM Symposia, Inc., PO Box 27646, 85285-7646 Tempe, AZ (United States)
OSTI ID:
23005539
Report Number(s):
INIS-US-21-WM-P6; TRN: US21V1465045873
Resource Relation:
Conference: WM2019: 45. Annual Waste Management Conference, Phoenix, AZ (United States), 3-7 Mar 2019; Other Information: Country of input: France; 6 refs.; available online at: https://www.xcdsystem.com/wmsym/2019/index.html
Country of Publication:
United States
Language:
English