Retro-Fit Denitrification for Small Wastewater Treatment Facilities Tenth Annual Vail Professional Wastewater Operators Seminar Friday, October 29, 2004 Zachary J. Matyja, E.I.T. Jacobson Helgoth Consultants, Inc. Jacobson Helgoth Consultants, Inc.

Retro-Fit Denitrification Improvements Presentation Outline Denitrification Process Improvements at Genesee Water and Sanitation District Implementation Process Questions 2 Jacobson Helgoth Consultants, Inc.

Retro-Fit Denitrification Improvements Denitrification Process 3 Jacobson Helgoth Consultants, Inc.

Retro-Fit Denitrification Improvements Denitrification Process Ammonia (NH3) In WW Process, Nitrogen bonds to Organic Molecules to form Ammonia-Nitrogen (NH3 & NH4) NH3 Converted to Nitrates in Aeration Process Nitrates (NO3) Common in Natural Water Sources include: Ag Runoff, Organic Matter, WWTF Discharges 10 mg/L Limit for Drinking Water Can Cause “blue baby syndrome” 4 Jacobson Helgoth Consultants, Inc.

Retro-Fit Denitrification Improvements Denitrification Process The biological conversion of nitrate-nitrogen to nitrogen gas (N2), nitrous oxide (N2O), and nitric oxide (NO) Occurs under anoxic conditions (no free oxygen available) Various Denitrification Processes Attached Growth Proprietary Processes Single-Sludge Nitrification/Denitrification 5 Jacobson Helgoth Consultants, Inc.

Retro-Fit Denitrification Improvements Single-Sludge Nitrification / Denitrification All modifications to existing nitrification facility take place in aeration basin Anoxic Zone precedes Aeration Internal Water Recycle (400-500% of Influent Flow) N2 Gas RECYCLE Influent Anoxic Zone (Denitrification) Aeration Zone (Nitrification) Effluent 6 Jacobson Helgoth Consultants, Inc.

Retro-Fit Denitrification Improvements Effect of Recycle on Nitrate Reduction 7 Jacobson Helgoth Consultants, Inc.

Retro-Fit Denitrification Improvements Denitrification Chemistry Ammonia First Passes Through Anoxic Zone Ammonia is Converted to Nitrate in Aeration Zone Nitrate are Recycled to Anoxic Zone Nitrate are Converted to Nitrogen gas in Anoxic Zone NO3 Converted to N2 NH3 Converted to NO3 N2 Gas RECYCLE Effluent Influent Anoxic Zone (Denitrification) Aeration Zone (Nitrification) 8 Jacobson Helgoth Consultants, Inc.

Retro-Fit Denitrification Improvements Denitrification Calculations Conventional Nitrification Calculations Required First Denitrification Calculations, Solve For Recycle Ratio Aerobic / Anoxic Residence Times Aerobic / Anoxic Tank Volumes Aerobic / Anoxic Ratio 9 Jacobson Helgoth Consultants, Inc.

Retro-Fit Denitrification Improvements Genesee Water and Sanitation District Wastewater Treatment Facility 1010 Jacobson Helgoth Consultants, Inc.

Retro-Fit Denitrification Improvements Project Background In Foothills West of Denver, Near I-70 District Serves 4,000+ People Activated Sludge Facility Discharge to Bear Creek 1111 Jacobson Helgoth Consultants, Inc.

Retro-Fit Denitrification Improvements Need for Project 2002 Drought – Low Flows in Bear Creek Bear Creek Water Quality for Downstream Users Potential District Water Quality Problems Potential Water Reuse “Stay Ahead of the Game” Potential Future Nitrate Effluent Regulations 1212 Jacobson Helgoth Consultants, Inc.

Retro-Fit Denitrification Improvements Existing Wastewater Process Schematic Two Aeration Basins Operated in Parallel (0.25 MGD Capacity, Each) Three Secondary Clarifiers Operated in Series D I S C H A R G E Screening Clarifier Clarifier Clarifier Grit Aeration Basins (typ.) Sand Filter Chlorine RAS 1313 Jacobson Helgoth Consultants, Inc.

Retro-Fit Denitrification Improvements Existing Conditions Activated Sludge Facility Design Flow 0.5 MGD Actual Flows ≈ 0.25 MGD Achieving Near Complete Nitrification Previous Average Conditions: Influent Effluent Limits Ammonia (mg/L) 25-40 < 1.0 9-18.5 Nitrates (mg/L) < 0.5 15-23 None 1414 Jacobson Helgoth Consultants, Inc.

Retro-Fit Denitrification Improvements Denitrification Calculation Results Estimated Recycle Ratio = 295% Aerobic Residence Time Required = 4.8 hours Anoxic Residence Time Required = 2.0 hours Aerobic Tank Volume Fraction = 71% Anoxic Tank Volume Fraction = 29% 1515 Jacobson Helgoth Consultants, Inc.

Retro-Fit Denitrification Improvements Denitrification Design Drawings 1616 Jacobson Helgoth Consultants, Inc.

Retro-Fit Denitrification Improvements Denitrification Design Baffle Wall in Aeration Basin Install Reinforced Flexible Baffle Curtain to Divide Basins Attached on all sides to Basin 3’ x 4’ Hole in Bottom Corner Furnished and Installed by Lange Containment Systems, Inc. 1717 Jacobson Helgoth Consultants, Inc.

Retro-Fit Denitrification Improvements Baffle Wall Installation 1818 Jacobson Helgoth Consultants, Inc.

Retro-Fit Denitrification Improvements Denitrification Design Submersible Mixer Ensure Successful Mixing of Entire Anoxic Basin Primary purpose to keep all solids in suspension, and prevent settling in Anoxic Basin Evaluated Two Mixers, Flygt required two mixers to accomplish same mixing Selected USFilter EMU Uniprop 1919 Jacobson Helgoth Consultants, Inc.

Retro-Fit Denitrification Improvements Mixer Installation 2020 Jacobson Helgoth Consultants, Inc.

Retro-Fit Denitrification Improvements Denitrification Design Drawings 2121 Jacobson Helgoth Consultants, Inc.

Retro-Fit Denitrification Improvements Denitrification Design Drawings Piping Design From Pump 2222 Jacobson Helgoth Consultants, Inc.

Retro-Fit Denitrification Improvements Denitrification Design Submersible Pump Designed for 900 gpm, 10’ TDH 5 hp, 1750 rpm, submersible motor Guide Rails to Raise Pump ITT Flygt Submersible Sewage Pump Purchased 2323 Jacobson Helgoth Consultants, Inc.

Retro-Fit Denitrification Improvements Pump Installation 2424 Jacobson Helgoth Consultants, Inc.

Retro-Fit Denitrification Improvements Denitrification Design Flow Measurement Electromagnetic Flow Meter – Endress + Hauser, Promag 50W Flow Control Ballcentric Plug Valve with Handwheel Gear – Pratt Piping and Related Equipment C900 PVC Pipe, Fittings, and Glue Ductile Iron Pipe, Fittings, and Hardware Pipe Hangers, Support Brackets, and Hardware 2525 Jacobson Helgoth Consultants, Inc.

Retro-Fit Denitrification Improvements Flow and Piping Installation 2626 Jacobson Helgoth Consultants, Inc.

Retro-Fit Denitrification Improvements Denitrification Design Electrical Modifications Breakers, Starters, Controls Installed for Pump, Meter, Mixer Installed by Sub-Contractor 2727 Jacobson Helgoth Consultants, Inc.

Retro-Fit Denitrification Improvements Denitrification Installation Aeration Basin Offline Basin Power Washed Diffusers Removed / Plugged Baffle Wall Installed by Sub-Contractor Pump, Piping, Mixer Installed Electrical Hook-up by Sub-Contractor 200 Man-Hours by District Staff 100 Man-Hours Electrical Sub-Contractor 300 Man-Hours Total 2828 Jacobson Helgoth Consultants, Inc.

Retro-Fit Denitrification Improvements Denitrification Results at Genesee Current Recycle Rate set at ≈ 230% Effluent Nitrate Levels 3-5 mg/L (78% Reduction) 2929 Jacobson Helgoth Consultants, Inc.

Retro-Fit Denitrification Improvements Additional Benefits found at Genesee A Substantial Decrease in Added Alkalinity Requirements has been Noted Alkalinity is recovered in Recycled Water in Anoxic Zone Better Settling and Clarity has been Noted in Clarifiers A Decrease in Aluminum Sulfate Usage has been Noted Due to Increased Biological Phosphorous Uptake More Effective Dewatering Process (Centrifuge) Reduced Air Requirement in Aeration Basins 3030 Jacobson Helgoth Consultants, Inc.

Retro-Fit Denitrification Improvements Negatives to Denitrification found at Genesee Initial Electrical Consumption has increased 15% From Pump, Mixer, and Meter Usage May Decrease because of Reduced Air Requirements Initial Operation Requirements to Determine Recycle Ratio More Frequent Monitoring for Filamentous Control in the Anoxic Zone 3131 Jacobson Helgoth Consultants, Inc.

Retro-Fit Denitrification Improvements Total Costs $46,000 for One (0.25 MGD) Aeration Basin Conversion Engineering – $ 6,500 Baffle Wall – $ 6,200 Pump & Equip. – $ 4,900 Jib Crane & Trolley – $ 1,400 Mixer & Equip. – $10,300 Flow Meter – $ 2,900 Plug Valve – $ 500 Pipe, Supports, Etc. – $ 3,300 Electrical – $ 9,900 3232 Jacobson Helgoth Consultants, Inc.

Retro-Fit Denitrification Improvements Design Implementation 3333 Jacobson Helgoth Consultants, Inc.

Retro-Fit Denitrification Improvements Design Implementation Determine Need Establish Funding Engineering Calculations / Design Equipment / Materials Selection Determine Resources Available Installation Financial / Chemical Changes 3434 Jacobson Helgoth Consultants, Inc.

Retro-Fit Denitrification Improvements Questions? Zach Matyja zmatyja@jacobsonhelgoth.com Jacobson Helgoth Consultants, Inc. www.jhcinc.com (303) 986-0733 3535 Jacobson Helgoth Consultants, Inc.