Looking Under the Hood of Your Sequencing Batch Reactor An Optimization Case Study

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Looking Under the Hood of Your Sequencing Batch
ReactorAn Optimization Case Study

• Bob Dabkowski
• Wastewater Specialist
• Hach Company
• bdabkows_at_hach.com

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SBR Operation
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SBR Operation

• Whats going wrong?
• How long do we aerate?
• When is nitrification complete?
• Can I denitrify? When is it complete?
• When do I begin decanting?
• Do I have enough solids/enough SRT?
• Am I wasting electricity? Where can I cut costs?
• Does my SBR perform differently in wet weather as
  opposed to dry weather?

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Look Under the Hood

• When things go wrong with our cars, we look under
  the hood.
• How do we look under the hood of our sequencing
  batch reactors?

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Case Study
Influent pumping station

• SBR in Messel, Germany
• Max flow 230m3/hr
• About 1.5 mgd
• Annual rainfall 725mm
• About 28.5 inches
• Combined Sewers
• Wanted to handle more flow
• without expanding

Primary Treatment
Influent holding tank
SBR 1
Final Filter
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Case Study

• Looking Under the Hood
• online continuous monitoring
• Total Suspended Solids
• Ammonia
• Nitrate
• Dissolved Oxygen
• Sludge Blanket Level

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Data
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Results

• A
• Reactor is partially filled, then aerated
• Nitrification begins

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Results

• B
• Reactor is filled completely
• Aeration stopped, denitrification begins

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Results

• C
• Nitrification
• Phase
• Extra aeration
• Wasted money
• Wasted time
• Save 65min

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Results

• D
• Settle Decant
• Good settling sludge, could begin to empty at 4ft
  from surface instead of 9ft
• Save 60min

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Conclusion

• Dry Weather
• Same level of treatment could be achieved in 6hr
  instead of 8hr
• Energy savings as a bonus

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Data
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Results
Over settled
Over aerated
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Conclusion

• Wet Weather
• 6hr cycle can be reduced even more
• Energy savings as a bonus

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What About ORP?
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What About ORP?

• ORP can be a surrogate control measurement
• Measures everythingnot specific
• Be sure to verify correlations periodically
• ORP alone doesnt tell you anything
• Can correlate to NO3, NH3
• Monitor DO
• Install about 1ft below water level
• Ex ball float mounting hardware

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Look Under the Hood

• An ounce of prevention is worth a pound of cure.

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Looking Under the Hood of Your Sequencing Batch
ReactorAn Optimization Case Study

• Bob Dabkowski
• Wastewater Specialist
• Hach Company
• bdabkows_at_hach.com