Cost Effective Mixing and Biological Nutrient Removal (BNR ... Effective Mixing - Tyler Kunz.pdf · and Biological Nutrient Removal (BNR) at Warren WWTP Presented By: Tyler Kunz,

Cost Effective Mixing and Biological Nutrient Removal (BNR)

at Warren WWTP

Presented By: Tyler Kunz, P.E. EnviroMix

Overview • 36 MGD Wastewater Treatment

Facility

• Anaerobic Zones at Front End of Four

(4) Aeration Basins.

Remove Fine Bubble Diffusers Add Baffles Install BioMixTM Compressed

Gas Mixing System • Part of Johnson Controls, Inc.

Performance Contract for Energy and Operational Savings

• Startup Spring 2014

Cost-Effective Mixing Warren, MI

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Objectives

• Achieve Biological Phosphorous Removal

• Reduce Cost of Chemicals (Ferric Chloride)

• Effectively and Efficiently Mix Anaerobic Zones

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Phosphorous Removal Through Chemical Precipitation

• Removal Mechanism • Soluble phosphorous adsorbs to Hydrous Metal Oxide (HMO) sites • Additional phosphorous (P precipitate and Bugs) are enmeshed within the HMO

• Common Chemicals • Alum, Sodium Aluminate, Ferric Chloride, Poly Aluminum Chloride

• Drawbacks • Expensive chemicals • Higher sludge production • Some chemicals consume alkalinity (may inhibit nitrification)


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Biological Phosphorous Removal

• Anaerobic Conditions • Phosphorous Accumulating Organisms (PAO’s) release intercellular phosphorous for energy

required to absorb Volatile Fatty Acids (VFA’s) and store as Polyhydroxybutyrate (PHB) • Aerobic Conditions

• PAO’s utilize the stored PHB as a food source for rapid cell growth • In the process they re-absorb soluble phosphorous in excess of what was released (Luxury

Uptake) • Phosphorous Removal

• Phosphorous now bound in cellular structure is removed by wasting sludge


PHB PHB

Poly-phosphate

Polyphosphate

Rapidly Biodegradable Substrate (VFA’s)

P Release

Excess P Uptake

Cell Synthesis

CO2 + H2O

O2 or NO3

Energy Energy

Anaerobic Aerobic

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Biological Phosphorous Removal - Simplified

Anaerobic Aerobic

• VFA uptake & storage (PHB) • Phosphorous release

• Stored “food” (PHB) oxidized • Cell synthesis • Excess phosphorous uptake

Phosphorous-rich WAS


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Process Modifications to Facilitate Biological Phosphorous Removal

• Pre-Anoxic Zone • Denitrification to limit the amount RAS-borne nitrates entering Anaerobic Zone

• Anaerobic Zone • Facilitate phosphorous release under anaerobic conditions

• Return Activated Sludge (RAS) • Reduced RAS from 150% down to 75% • Minimize nitrates returned to the Pre-Anoxic Zones


New Solutions for Old Problems

Point-Source Mixers

• Energy input is isolated

• Up to 2x the energy cost of

distributed energy model

• Submerged mechanical equipment

• Multiple mixers (maintenance

points) in large plants

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Nozzle Header System

• Distributed energy input

• Effective and efficient: 60%+ energy

savings

• No moving parts in the basin

• Many mixers replaced with a single

compressor

Distributed Energy Model


• Software & hardware solutions for water & wastewater treatment facilities - focused on efficient mixing systems

• Base technology- compressed gas mixing system-

intermittently firing short bursts of compressed air, nitrogen gas, or methane through engineered nozzles

• Large bubbles uniformly mix: Wastewater process tanks- Anoxic,

Anaerobic, Aerobic Digesters, channels, EQ tanks Potable water storage

• BioMix Technology creates solutions that:

Save Energy Reduce Maintenance Provide Guaranteed Mixing

Technology Overview

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BioMixTM – Compressed Gas Mixing

In-Tank Nozzles, Piping

and Anchors

Valve Panel w/ HMI Controller & Optional Remote

Monitoring

Compressor w/ Receiver

Tank(s)


Philadelphia (PA) SW WWTP

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Receiver Tank and Nozzle Headers


Philadelphia (PA) SW WWTP

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Valve Control Panel (VCP) w/ Control Interface and Remote Monitoring


Technology Overview

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• Large compressed gas volumes expand upward and outward

• Expanding bubbles provide controlled turbulence,

fluid currents and provide mixing

• Does so with negligible amount of oxygen transfer

• Ideal for Anoxic and Anaerobic Mixing Environments

• Non-clog & high pressure design ideal for thickened sludge applications


Franklin County (PA) General Authority WWTP Anaerobic Pre-EQ

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• Large bubbles produced by BioMixTM deliver negligible O2 transfer

• It is a function of Bubble Size and Volume

• BioMix large bubbles have significantly less surface area than diffused aeration:

– 90% less than Coarse Bubble

– 99% less than Fine Bubble

• BioMix, anaerobic ORP values less than or equal to submersible mixers in side-by-side comparison.

– Higher surface “churn” with submersible technology induces O2 transfer

• BioMix diffuses a fraction of the air volume as conventional aerated mixing

Fine Bubble

Coarse Bubble

BioMix

Bubble Diameter

Area:Volume Ratio

(ft2/ft3)

BioMix 4” 18

Coarse Bubble 3/8” 192

Fine Bubble 0.06” (1.5 mm)

1,220

Comparative Surface Area (Bubble Area in 1 cu ft of Air)

BioMix Negligible Oxygen Transfer


Benefits • Uniformly Distributed Mixing Energy

• Reduces Energy Consumption

• Improves Mixing

• Enhances Biological Nutrient Removal

(BNR)

Eliminates Cost of Chemicals for

Phosphorous Precipitation

Savings of up to $200k/Year

(4 Basins Operating)

• Operator Adjustable Firing Parameters

• Accommodates Variable Mixing

Intensity

• Optimize Energy Consumption

• No In Basin-Maintenance

• Minimize and Localize Maintenance

Requirements 13

Compressor Skid

3D Rendering of Basins 1 & 2

Rotary Screw Compressor


Performance Results

• BioMixTM Provides Complete Mixing

of Eight (8) Anaerobic Zones with

one (1) 15 HP Compressor

• Mixing Efficiency ~0.1 HP/1000 ft3 of

Tank Volume

• Consistently Achieving Effluent Total

Phosphorous of < 0.5 mg/l with No

Chemical Addition

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Nozzle Header System


BioMix-AD: Little Rock (AR) Wastewater Utilities, Primary #3

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BioMix-AD: Little Rock (AR) Wastewater Utilities, Primary #3

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Municipal Wastewater Applications

Anoxic

BNR System

Channels

Sludge Storage

EQ

Sludge Digestion

Aeration

Pump

Station

Anaerobic

Swing Zone

Chlorine Contact

Chamber

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Anoxic/Anaerobic Mixing BioMixTM

Low O2 Demand/Mixing Limited

Aeration Zones

(De-couple Aeration and Mixing)

Channel Mixing

Sludge Storage

Equalization/Storm Water Holding

Aerobic SHT and Digesters

(De-couple Aeration and Mixing)

Septage Receiving

Anaerobic Digesters


Technology Overview

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• Fits virtually any tank configuration

• Energy input can be varied to provide mixing intensity required

• Negligible O2 transfer due to low A:V ratio of large bubbles

• Equal or lower ORP compared to submersible mixers

• 60%+ Energy Savings vs. point-source mixing

• Even higher vs. diffused aeration (channels, sludge storage etc…)

• Replace many Mixers w/ 1 compressor

• No In-Tank Maintenance

Reduced Maintenance

Reduced Energy Consumption

Highly Scalable and Flexible Operation

Facilitate Anoxic/Anaerobic

Conditions


Warren, MI WWTP 32630 Warkop Warren, MI 48093 (586) 264-2530

• Dave Monette – Division Head

• Todd Schaedig – Facilities Engineer

• Bob Dranberg – Chief Operator


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EnviroMix - Corporate Headquarters 180 East Bay Street, Suite 200 Charleston, SC 29401 (843) 573-7510 www.enviro-mix.com

Thank You!

http://www.enviromix.com/



Documents

Cost Effective Mixing and Biological Nutrient Removal (BNR ... Effective Mixing - Tyler Kunz.pdf · and Biological Nutrient Removal (BNR) at Warren WWTP Presented By: Tyler Kunz,