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New Nuclear Power and Climate Change: Issues and Opportunities

New Nuclear Power and Climate Change: Issues and Opportunities

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New Nuclear Power and Climate Change: Issues and Opportunities

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  1. New Nuclear Power and Climate Change: Issues and Opportunities Student Presentation Ashish K Sahu and Sarina J. Ergas University of Massachusetts - Amherst

  2. Perchlorate Reduction in a Packed Bed Bioreactor Using Elemental Sulfur Ashish K Sahu and Sarina J. Ergas

  3. Background • Perchlorate (ClO4-) • Stable • Non reactive • Trace levels of Perchlorate • Disruption of hormone uptake in thyroid glands

  4. Geographic Contamination • No National Standards • MCL set by the Commonwealth of Massachusetts (2 mg/L) • California advisory levels (6 mg/L) • Other states (NY, NV, AZ, CO, TX) 18 mg/L Ref: ewg.org

  5. Sources of Perchlorate • Natural • Atmospheric Sources • Chilean nitrate fertilizer • Anthropogenic • Missiles, Rockets • Fireworks • Leather Tannery Industries • Fertilizers

  6. Treatment Processes • Physical Processes • Chemical Processes • Biological Processes • Combination of the above

  7. Perchlorate Treatment Processes Physical Destructive Process Hybrid Technologies Chemical Biological GAC Bioreactors Others RO/NF CC-ISEP Phytoremediation Reducing metals IX Electrodialysis Others (MBR) CSTR PFR Bio-remediation

  8. Outline • Biological Perchlorate Reduction • Use of Elemental Sulfur • Experimental Protocol • Results • Conclusions

  9. Heterotrophic microorganisms Use organic carbon as their carbon source Electron donors are methanol, lactate, ethanol, wastewater Autotrophic microorganisms Use inorganic carbon as their carbon source eg: NaHCO3 Electron donors are S, Fe0, H2 Biological Perchlorate ReductionPrinciple: Microorganisms convert perchlorate to chloride

  10. Use of Elemental Sulfur 2.87 S + 3.32 H2O + ClO4- + 1.85 CO2 + 0.46 HCO3- + 0.46 NH4+→ 5.69 H+ + 2.87 SO42- + Cl- + 0.462 C5H7O2N • Electron Donor: Elemental Sulfur • Electron Acceptor: Perchlorate • Carbon Source: Bi-carbonate • Low biomass production • Low nutrient requirements • Anoxic conditions • Alkalinity destroyed

  11. Advantages of Elemental Sulfur • Waste byproduct of oil refineries • Excellent packing media • Relatively inexpensive and easily available • Applications in packed bed reactors and permeable reactive barriers

  12. Objectives • Enrich a culture of Sulfur Utilizing Perchlorate Reducing Bacteria (SUPeRB) • Investigate the use of packed bed bioreactors to treat perchlorate contaminated waters by SUPeRB • Test the bioreactor for varying operating conditions

  13. Batch Culture Enrichments • Denitrification zone of Berkshire wastewater treatment plant, Lanesboro, MA • 5mg/L ClO4-, So and oyster shell, nutrients in groundwater • Analytical Techniques • pH • ClO4- concentration using IC (EPA method 314.0)

  14. Batch Culture Enrichment (SUPeRB)

  15. Packed Bed Reactor • Reactor inoculated with SUPeRB • Media: Elemental Sulfur pellets (4 mm), oyster shell (3:1 v/v) • Volume: 1 liter • Ports: 5 ports

  16. Packed Bed Reactor Operation

  17. Bioreactor Performance-Phase II(Effect of Empty Bed Contact Time (hrs))

  18. Bioreactor Performance-Phase II(Effect of Empty Bed Contact Time)

  19. Bioreactor Performance-Phase II(Effect of sulfur size particles)

  20. Bioreactor Performance-Phase II(Effect of Nitrate on Perchlorate Removal)

  21. Summary • SUPeRB reduced ClO4- from 5 mg/L to <0.5 mg/L in 15 days using S0 and OS • High levels of perchlorate (5-8 mg/L) were successfully reduced to < 0.5 mg/L in the bioreactor at an EBCT of 13 hours • Low levels of perchlorate (80-120 mg/L) were reduced to < 4 mg/L at an EBCT of 8 hours

  22. Summary… • Presence of nitrate did not inhibit perchlorate reduction • Perchlorate reduction was somewhat independent of media particle size

  23. Applications and Future Work • Pilot scale of system for perchlorate remediation • Ex-situ remediation • In-situ remediation by Permeable Reactive Barriers (PRBs)

  24. Acknowledgements • Water Resources Research Center (WRRC), TEI at UMass-Amherst • Massachusetts Technology Transfer Center (MTTC) for commercial potential • Advisor: Dr. Sarina Ergas • Teresa Conneely, Department of Microbiology for FISH and microbiology analysis • Tach Chu and Charlie Moe (High School) for culture and bioreactor maintenance

  25. Thank you for your kind attention Email: aksahu@acad.umass.edu SUPeRB is SUPERB!!!