1 / 32

Deep Bed Denitrification Performance

Deep Bed Denitrification Performance. Cold Weather Operation for Two Northeast WWTPs Presented by: Gary M. Lohse, P.E., Severn Trent Services Ken Wineberg, Severn Trent Services. The Nitrogen Cycle via Biological Processes. ORGANIC NITROGEN (Proteins, Urea, etc.). Bacterial

trevor
Download Presentation

Deep Bed Denitrification Performance

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Deep Bed Denitrification Performance Cold Weather Operation for Two Northeast WWTPs Presented by: Gary M. Lohse, P.E., Severn Trent Services Ken Wineberg, Severn Trent Services

  2. The Nitrogen Cyclevia Biological Processes ORGANIC NITROGEN (Proteins, Urea, etc.) Bacterial Decomposition & Hydrolysis AMMONIA NITROGEN ORGANIC NITROGEN (Bacteria Cells) ORGANIC NITROGEN (Net Growth) O2 Lysis & Auto Oxidation NITRITE (NO2-) O2 Denitrification NITRATE (NO3-) NITROGEN GAS (N2) Organic Carbon

  3. Deep Bed Denitrification Filter General Overview • Dissolved nitrate (NO3) is converted to nitrogen gas (N2) • Heterotrophic bacteria • - Use the O in NO3- as final e- acceptor when free dissolved O2 is not available (anoxic environment) • - Need organic carbon source for energy and cell-building • - Easy to stop and start • - Prefer pH range is neutral – works in range of ~ 6.0 to 8.2 • - Need nutrients such as P, often already available in wastewater • - Reaction rate affected by temperature, carbon source & potential toxins

  4. Deep Bed Denitrification Severn Trent Services 4

  5. Deep Bed Denitrification Filter - Profile of Components Media Support Gravel Underdrain BW Air Header BW Air Lateral Sump Cover Plate Sump

  6. Deep Bed Denitrification Filter - Underdrain system Support Media and Gravel Handle Hydraulic Shocks – minimize possible damage to filter internals Minimize Potential Pluggage in Applications with High Solids Loading or Biological Activity Collect Filtrate in Normal Operating Mode Helps Evenly Distribute BW Air & Water Across Entire Area of the Filter Bed

  7. Deep Bed Denitrification Filter - Air & Water Flow through underdrain Downflow Operating Mode Upflow Backwash Mode

  8. Deep Bed Denitrification Filter - Air & Water Distribution System • Stainless Steel Box Header • Air Laterals, Stainless Steel • Protected from Gravel & Media • Located Under Snap T BlockTM Arch • Located under every other row • Water Slot in Sump Cover • Located under every other row, where there is no air lateral

  9. Deep Bed Denitrification Filter - Methanol (carbon) System • Tank Volume Standard 21-30 Day Supply @ Average Flow • Tank Continuous Level Measurement • Tank Low and High Level • Methanol Pumps • Diaphragm • Peristaltic

  10. Supplemental Carbon Control Flow Meter Influent Denitrification Filters Effluent FE Influent Sample Nitrate Analyzer Effluent Sample Controller (MMI) Carbon Feed Pump

  11. Deep Bed Denitrification Filter - Backwash (Solids Removal) 3 Basic Cycles Backwash Air Only: - 1 to 3 min - Backwash Air Rate of 5 CFM/ft2 Backwash Air/Water Scour: - 10 to 15 min (trough overflow time) - Backwash Air Rate of 5 CFM/ft2 - Backwash Water Rate of 6 GPM/ft2 Backwash Water Only Rinse: - 5 min - Backwash Water Rate of 6 GPM/ft2

  12. Deep Bed Denitrification Operation- Filtration

  13. Deep Bed Denitrification Operation - Clearwell

  14. Deep Bed Denitrification Operation – Air Backwash

  15. Deep Bed Denitrification Operation – Water Backwash

  16. Deep Bed Denitrification Operation – Air/Water Backwash

  17. Deep Bed Denitrification Operation - Mudwell

  18. Factors Affecting Denitrification Filter Design • Influent NO3-N Concentration • Dissolved Oxygen (DO) Concentration  Low DO Preferred • Carbon Source Characteristics & Availability • Alkalinity: 50 PPM+ Preferred • pH Range: 6-8.2 Preferred  7.0-7.5 Optimum • Presence of Nutrients and/or Toxins • Temperature • Reaction Time: Empty Bed Detention Time (EBDT)

  19. Scituate, MassachusettsCommissioned in 2000

  20. Scituate, Massachusetts

  21. Denitrification Filter Design Criteria Design Value Average flow: 1.60 mgd Max day flow: 2.36 mgd Peak hour flow: 4.34 mgd Average TSS: 15 mg/L Average NO3-N: 13 mg/L Temperature: 8 deg Celsius Plant Effluent TSS: 5 mg/L NO3-N: 0.5 mg/L TN: 4 mg/L Denitrification Filters Average hydraulic loading 1.22 gpm/sf Peak hydraulic loading 3.30 gpm/sf 12 month rolling average

  22. Methanol System Scituate WWTP Filter System

  23. Average Operating DataApril 2001Through November 2006 Flow Rate Average: 1.22 mgd Max day: 3.54 mgd Peak hour: 4.20 mgd Plant Effluent (Average) CBOD: 3.1 mg/L TSS: 4.5 mg/L TN: 2.9 mg/L Denitrification Filters Average hydraulic loading: 0.70 gpm/sf Peak hydraulic loading: 2.40 gpm/sf 12 month rolling average

  24. Cold Temperature Operating DataScituate WWTPApril 2001 Through November 2006

  25. Cold Temperature Operating DataScituate WWTPDec 2006 Through May 2007

  26. Allegany County, MarylandCelanese WWTPCommissioned in 2005

  27. Allegany County, MDCelanese WWTP 2.86 MGD Design Clarifiers Single Stage Activated Sludge Denitrification Filters Head Works

  28. Denitrification Filter Design Criteria Design Value Average flow: 1.66 mgd Max Month flow: 2.86 mgd Peak hour flow: 6.6 mgd Average TSS: 30 mg/L Average NO3-N: 26 mg/L Temperature: 11 deg Celsius Plant Effluent TSS: 5 mg/L NO3-N: 2 mg/L TN: 3 mg/L Denitrification Filters Average hydraulic loading 2.6 gpm/sf Peak hydraulic loading 6.0 gpm/sf Annual Average

  29. Cold Temperature Operating DataCelanese WWTPDec 2009 Through May 2012

  30. Additional Cold Weather Deep Bed Denitrification filters • New York – 2 • Pennsylvania – 2 • Maryland – 5 • Virginia – 8 • Massachusetts – 4 • Colorado – 1 • California – 2 (High Elevations)

  31. Conclusion • Deep beds allow maximum ability for solids to be captured providing for consistently low TSS and turbidity effluents with a varying load of TSS • Filter media becomes attachment site for denitrifying bacteria in which dissolved nitrate (NO3) is converted to nitrogen gas (N2) providing nitrogen removal through a biological process • Need organic carbon source for energy and cell-building and nutrients such as P, often already available in wastewater • Backwash water is typically only 2 – 4 % of forward flow. Lower backwash consumption and recycle cuts plant operating costs and increases plant capacity. • Reaction rate affected by temperature, carbon source & potential toxins • Deep Bed Denitrification filters can achieve TSS of below 4 mg/l and TN limits of below 3 mg/l even in cold climates

  32. Cold Weather Deep Bed Denitrification Filters Questions?????? CONTACT: Gary M. Lohse, P.E. Regional Sales Manager Severn Trent Services 3000 Advance Lane Colmar, Pa 18915 Cell: (215) 859 - 3814 Direct: (215) 997-4052 Fax: (215) 997-4062 Email: glohse@severntrentservices.com

More Related