hg fate and transport within the san jose/santa clara wpcp: study design and interim progress report...
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Hg Fate and Transport Within the Hg Fate and Transport Within the San Jose/Santa Clara WPCP:San Jose/Santa Clara WPCP:
Study Design and Interim Progress Study Design and Interim Progress ReportReport
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Why?
• Baywide Hg TMDL• Anything Special About POTW Hg?• Do POTWs Methylate Hg?• Where Does the Hg Go?
• NPDES Discharge Permit Provision• Workplan (collection and analytical methods, schedule)• Final Report (Hg F&T, Trends, Correlations, Evaluate
Feasibility of CH3Hg Reduction Program)
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Steps to CompletionMethod Development WorkplanLiterature ReviewDetailed SAPPhase 1 Sample CollectionStudy OptimizationPhase 2 SamplingFinal Report
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MethodDevelopment
The Treatment Process (simplified)
Treatment Process
The PlanPhase 1
Weekly RS, PE, SS, NE, SE, FI, TFE, FE Total, Filtered, Total Methyl (Selected Filtered
Methyl) TSS, Chloride, Sulfate, Sulfide DO, Temp, pH, Conductivity
Monthly As above + Secondary/ Nitrification Quads Sludge Seasonal 24 hour sampling Monthly
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The PlanPhase 2
Longer term, reduced frequency Monthly RS, PE, NE, SE, FI, TFE, TFBW, FE Weekly RS, FE
Special Focused Studies More sludge? Composites? More 24 hour samples? Other parameters?
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TSS(mg/L)
195
9095
8 8 7 102<1
0
50
100
150
200
250
RS PE SS N E SE FI TFE FBW FE
Total Mercury(ng/L)
178.6
94.2 87.7
5.5 5.2 5.3 1.7 5.6 2.20
50
100
150
200
250
300
RS PE SS N E SE FI TFE FBW FE
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Methylmercury(ng/L)
1.551.47
1.29
0.05 0.05 0.030.11
0.040.04 0.030.03
0.11
0.0
0.5
1.0
1.5
2.0
2.5
RS PE SS N E SE FI TFE FBW FE
Total
Filtered
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Dissolved Mercury (ng/L)
3.12
4.11
3.58
1.011.14 1.17 1.25
2.48
1.48
0.0
1.0
2.0
3.0
4.0
5.0
RS PE SS N E SE FI TFE FBW FE
* **
*
* Addition of Cl2 or H2O2
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24 Hr. TSS in RS (mg/L)
0
50
100
150
200
250
300
06:00 10:00 14:00 18:00 22:00 02:00
4/28/2005
6/23/2005
9/22/2005
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24 Hr. Total Hg in RS
0
50
100
150
200
250
300
350
400
06:00 10:00 14:00 18:00 22:00 02:00
4/28/2005
6/23/2005
9/22/2005
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24 Hr. Dissolved Mercury in RS (ng/L)
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
06:00 10:00 14:00 18:00 22:00 02:00
4/28/2005
6/23/2005
9/22/2005
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Sludge Total Mercury(mg/kg dry) n=5
1.80
0.72
0.84 0.85
1.55
1.90
0.0
0.5
1.0
1.5
2.0
2.5
PS WAS WNS TAS DS SL
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Mass Balance?
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Interim Conclusions
• Efficiencies:– HgTOT 99%– Methyl Hg 97%– Dissolved Hg 50%
• Removal correlated with solids removal• No evidence of methylation• Flows sufficient to account for removal• Temporal bias (daily fluctuation)
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Next Steps
• Continue baseline Phase II sampling
• Independent review of Phase I results
• Discuss with Water Board
• Optimize sampling to answer questions
• Carry out optimized sampling
• Final Report 2007
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