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BOD, COD and you use a lab sample? PowerPoint Presentation
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BOD, COD and you use a lab sample?

BOD, COD and you use a lab sample?

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BOD, COD and you use a lab sample?

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  1. BOD, COD and you use a lab sample? 2nd Water/Wastewater and Automatic Controls Conference Orlando August 9, 2007

  2. Presenter Robert Lagrange Co author Business Manager Tracy Doane-Weideman Water and Wastewater Product Manager Analysis Endress+Hauser Inc.

  3. Schedule • Organic Load • Importance for plant operation • Laboratory Measurements • BOD 5 • COD • On-Line Measurements • BOD • COD • Questions

  4. Is it important to know the organic load ? • A change of organic load requires process adjustments • Controlling the Dissolved Oxygen concentration in the aeration tank is a typical way to compensate for this • But !!!! It could be too late if the plant capacity is limited It is better to know ahead of time, much more if there is a possibility to equalize the load or limit the intake of high load from industrial plants

  5. BOD variations at a municipal WWTP Reference: Finbarr O Riordan

  6. Measurement of Organic Load • TOC • COD • BOD “the fundamental purpose of the treatment plant is to reduce the bio-digestible organics”

  7. Issues with laboratory measurement • BOD 5 Lab • Takes 5 days • Accuracy/Repeatability

  8. Accuracy of lab measurement Reference: M. Köhne

  9. Issues with laboratory measurement • BOD 5 Lab • Takes 5 days • Accuracy/Repeatability • COD • Takes 2 hours • Maintenance of the lab instrument • Disposal of waste stream depending on method

  10. O2 Uptake mg/l Michaelis- Menten Kinetics Model 3 mg O CONTROL POINT 2 5 m g B O D / l Nutrient Concentration in mg BOD / l Michaelis- Menten Kinetic Model

  11. How does it work? • Thousands of small plastic rings within the bioreactor provide a growth surface for the biomass. • The biomass is fed a mixture of wastewater and oxygen saturated dilution water • The dilution is constantly adjusted to maintain a 3mg/l oxygen consumption • The ratio of wastewater to dilution water defines BOD based on the Michaelis- Menten Kinetic Model

  12. Construction

  13. Before Calibration After Calibration Trending & Calibration Reference: Alexander Borys

  14. Another trending example Reference: Finbarr O Riordan

  15. Reference: Finbarr O Riordan Reference: Alexander Borys Maintenance On-line BOD

  16. On-Line COD • Ozone is mixed with dilution water. The resulting concentration is measured by the first ozone sensor. • In the reaction chamber the waste water is oxidized by the ozonized dilution water • The ozone concentration in the reactor is measured by the second ozone sensor. • The consumption of Ozone is proportional to the COD

  17. Use of BOD for monitoring and control

  18. Use of BOD for balancing load

  19. Thank you ! Questions ?