new nuclear power and climate change: issues and opportunities student presentation ashish k sahu...
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New Nuclear Power and Climate Change:
Issues and Opportunities
New Nuclear Power and Climate Change:
Issues and Opportunities
Student Presentation
Ashish K Sahu and Sarina J. Ergas
University of Massachusetts - Amherst
Department of Civil and Environmental Engineering
Perchlorate Reduction in a Packed Bed Bioreactor Using Elemental Sulfur
Ashish K Sahu and Sarina J. Ergas
3Department of Civil and Environmental Engineering
Background
Perchlorate (ClO4-)
• Stable• Non reactive
Trace levels of Perchlorate• Disruption of hormone uptake in thyroid glands
4Department of Civil and Environmental Engineering
Geographic Contamination
No National Standards MCL set by the
Commonwealth of Massachusetts (2 g/L)
California advisory levels (6 g/L)
Other states (NY, NV, AZ, CO, TX) 18 g/L
Ref: ewg.org
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Sources of Perchlorate
Natural• Atmospheric Sources• Chilean nitrate fertilizer
Anthropogenic• Missiles, Rockets • Fireworks• Leather Tannery Industries• Fertilizers
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Physical Processes Chemical Processes Biological Processes Combination of the above
Treatment Processes
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Perchlorate Treatment Processes
Physical Destructive Process
ChemicalBiological
GAC
RO/NF
Electrodialysis
CC-ISEP Bioreactors
Hybrid Technologies
Bio-remediation
Phytoremediation
IX
Others
Others (MBR)CSTR PFR
Reducing metals
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Outline
Biological Perchlorate Reduction Use of Elemental Sulfur Experimental Protocol Results Conclusions
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Biological Perchlorate ReductionPrinciple: Microorganisms convert perchlorate to chloride
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
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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
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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
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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
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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)
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Batch Culture Enrichment (SUPeRB)
0.0
1.0
2.0
3.0
4.0
5.0
0 100 200 300 400
Days
ClO
4- m
g/L
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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
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Packed Bed Reactor Operation
Experimental Phase
Perchlorate concentration
mg/L
EBCT hrs
Recirculation RatioQR/Q
So particle
size
Phase I 5-8 13-100 Intermittent at(40-1,500)
4 mm
Phase II
Reactor 1 0.08-0.12 25-30 50-1,000 4 mm
Reactor 2 0.08-0.12NO3
--N (10 mg/L)8-30 None 4 mm
Reactor 3 0.08-0.12 8-30 None 0.85 mm
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Bioreactor Performance-Phase II(Effect of Empty Bed Contact Time (hrs))
020406080
100120140
0 50 100 150
Days
ClO
4- g
/L
Influent Effluent
30 15 12 8
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Bioreactor Performance-Phase II(Effect of Empty Bed Contact Time)
7589 87
96
0
20
40
60
80
100
120
28 15 11 7.5
Empty Bed Contact Time (hrs)
Ave
rag
e %
ClO
4- rem
ova
l
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Bioreactor Performance-Phase II(Effect of sulfur size particles)
6560
90
0
20
40
60
80
100
21 7.6 4
Empty bed contact time (hrs)
Ave
rag
e %
ClO
4- re
mo
val
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Bioreactor Performance-Phase II(Effect of Nitrate on Perchlorate Removal)
0
2
4
6
8
10
12
14
0 5 10 15 20 25 30 35
Distance cm
NO
3- N
mg
/L
0
20
40
60
80
100
ClO
4- g
/L
Nitrate Perchlorate
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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 g/L) were reduced to < 4 g/L at an EBCT of 8 hours
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Summary…
Presence of nitrate did not inhibit perchlorate reduction
Perchlorate reduction was somewhat independent of media particle size
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Applications and Future Work
Pilot scale of system for perchlorate remediation
Ex-situ remediation In-situ remediation by Permeable Reactive
Barriers (PRBs)
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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
Department of Civil and Environmental Engineering
Thank you for your kind attention
Email: [email protected]
SUPeRB is SUPERB!!!