Resource Recovery from Effluent in Milwaukee, Wisconsin

Resource Recovery from Effluent in
Milwaukee, Wisconsin
June 25, 2015
Karen Sands, AICP
Manager of Sustainability
Milwaukee Metropolitan Sewerage District
Today’s Talk…
• MMSD Background
• Nutrient Recovery
• Heat Recovery
• Energy (from effluent plus…)
• Other Things
• Questions
6/30/2015
Milwaukee Metropolitan Sewerage District
We Serve:
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1.1 Million Customers
28 Municipalities
411 Square Miles
Using Grey Infrastructure:
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Collector Sewers
2 Treatment Plans
521 MG Tunnel Storage
To Protect the Environment:
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6/30/2015
Convey/Store/Reclaim Wastewater
Manage Flooding
Much More…
Below ground
Gallons of Storage
Long
In Diameter
MMSD’s Water Reclamation Facilities (WRFs)
Jones Island
South Shore
Our Water Reclamation Process
2014 = 99.5%
Downtown Milwaukee!
6/30/2015
Nutrient Recovery: Milorganite®
Made from:
• Digested and waste-activated sludge from SS digesters
• Primary sludge and waste-activated sludge from JI
98% of all biosolids produced is used to make Milorganite®
Nutrient Recovery: Milorganite®
What’s In The Bag?
• Guaranteed Analysis:
– 5.0% Total Nitrogen (N) = 3.5% Water Insoluble (slowrelease) N + 1.5% Water Soluble N
– 2.0% Available Phosphate (P2O5)
– 0.0% Potash (K-typically 0.5%)
– 1.2% Available Calcium (Ca)
– 4.0% Total Iron (Fe)
• Typical Micronutrients:
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0.58% Sulfur (S)
0.68% Magnesium (Mg)
0.045% Zinc (Zn)
0.022% Copper (Cu)
0.133% Manganese (Mn)
Trace amounts of Boron (B) and Molybdenum (Mo)
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Heat Recovery
South Shore WRF: Captured from engine generators and reused
in digesters, heat buildings
Jones Island WRF: Captured from LFG turbines and used to
preheat dryers, heat buildings
Digester Gas at South Shore WRF
8 Primary Digesters:
· 4 - 3.5 Million Gallon Capacity
· 2 – 1.5 Million Gallon Capacity
· 2 – 1.5 Million Gallon Digesters Used for Solids Storage
Input: Approximately 600,000 Gallons Of Sludge From
Treatment Process Per Day
Digester Gas Quantities
• Currently Produce About 900,000 Cubic Feet of Digester
Gas Per Day
• Gas Has A BTU Content About 60% Of Purchased NG
• Gas Is Burned By Engine Generators To Produce Electricity
• Currently Generate 2 Megawatts Per Day
• Require 4 Megawatts To Run Entire Reclamation Facility
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High Strength Waste
• 1998 Collaborative Project With Marquette
University, GMIA and MMSD
• Co-digested Glycol From Airport Deicing
Operations In MMSD Digesters
• COD Values 150,000 to 245,000 mg/L
• Performed 6 Full Scale Tests
• All at least 2 Weeks Apart
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Food Waste
• 2008 MMSD And Marquette University
Undertook Co-digestion Of Food Waste Study
• Received A $150,000 Grant From We Energies
• First Phase Small-scale Bench Testing
• Mixed MMSD Sludge With Waste From
Various Food Production Processes
• Measured Gas Production From Anaerobic
Reaction To Determine Best Performers
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MMSD Landfill Gas Project at JI WRF
While not recovered from WRF process,
recovered from a landfill and used in
the process…
• VES Owns Emerald Park Landfill
(EPL) in Muskego
• Agreement: MMSD + VES
• 16” LFG Pipeline from EPL to JIWRF
• Replace existing NG turbines with
turbines capable of burning LFG
• Save $ & Reduce Carbon Footprint
6/30/2015
Landfill Gas System Components
Dedicated Communication Link
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EMERALD PARK
(EPL)
EPL Gas Processing Facility
Compresses and conditions gas
for the pipeline and turbines
(JIWRF)
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Turbine Generators
produce electricity to power
JIWRF and waste heat to
produce Milorganite
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Pipeline transports gas
from EPL to JIWRF
Raw gas is drawn from collection
wells into a vacuum header system
Gas flow and quality
entering pipeline measured at EPL
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New Metering Station
measures gas flow and
quality exiting pipeline
Solar Energy Installations at MMSD
While not recovered from WRF
process, recovered from the sun
and used in the process…
Other Resource Recovery Things…
· Nutrient Recovery From Ion-Exchange
· FOG
· Bioplastics from Methane
· Pyrolysis of Biosolids
Pyrolysis of Biosolids
 Pyrolysis is the heating of organic material
 Organics are destroyed, producing a gaseous product
 A liquid fraction is also produced in the pyrolysis
 The pyrolysis process also produces biochar
Pyrolysis Process
Milwaukee’s Resource Recovery Plant
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QUESTIONS?
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