The Danish Story

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Wastewater, a Resource not a Burden!Flemming
B Møller Senior Technical Advisor, Project
Manager
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Flemming B Moller

• Senior Technical Advisor
• Project Manager
• Marine Engineer and experienced WWTP Operations
  Manager

Aarhus Water

• Volume of abstracted, treated and distributed
  drinking water 3957 M gallons/year
• Volume of processed wastewater 7915 M
  gallons/year
• Number of employees 209
• Annual budget 146 mill USD/year
• Our vision is to be a leader amongst water
  companies

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• Come learn more about... 
•          Net Zero WWT Plants, is that real?
•          How WWT anaerobic digesters can create
  revenue streams

A WRP consists of blocks, we know how to put them
together !
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Agenda.

• What steps have we taken to make the energy
  producing WWTP in Aarhus a reality?
• Reduction of energy
• Production of energy
• Struvite - From problem to resource
• Best Practices US/DK

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First Step for Aarhus Vand Energy Management
Our consumption of electricity used to be
large at our WWTP. In the fall of 2009, we were
energy certified according to the European DS
2403 standard in our efforts to reduce our energy
consumption.
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Reality where Does the Energy Go Electrical
Power Consumption
Aeration 37
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Energy Neutrality And Beyond
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The Development in electricy consumption
Marselisborg RA
Average 24 hour electricity consumption
Total reduction achieved 27
New Sandfilter 1000 kWh/d
New Blower
Process Optimizing
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Energy Balance - Power Self Sufficiency
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Introduction Marselisborg WWTP
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Energy Savings Power Production
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Optimization of N-removal and Power Consumption
Set Point

DO Ammonium Nitrate
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HV Turbo blowers - 1992

• Reduction in electricity consumption 300,000
  kWh/year
• CO2-reduction 153 tons/year
• Construction costs US 270.000
• ROI 4-5 years
• Key Figures
• Type HST 40-350-1-L-4
• Airflow 5000-16000 Nm3/h
• Power 350 Kw
• Pressure 430 mbar
• Water Depth 4 meter

ABS HST Compressor
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Specific Energy Consumption New Blower (HST
Compressor)
0,014 kWh/Nm3
Kapselblæsere, Nøgletal (Egå, Viby og Åby)
0,019-0,023 kWh/Nm3
Positive displacement blower, Key figures (Egå,
Viby og Åby) 0,019-0,023 kWh/Nm3
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Sludge Balances and Control of Aerobic Sludge Age
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Increasing Co-generation of Electricity/ Excess
Heat from Biogas
Replacement of 3 old gas engines with two high
efficiency - 2 pcs 250 kW - CHP units

• Construction costs 1,382,000 US CO2-reduction
  426 tons/year
• ROI 3 years
• Construction period 2010-12
• Electricity production (additional production)
  approx 1 mio kWh/year
• Power efficiency 38-39
• Excess heat efficiency 50-55
• Total efficiency 88-94

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Surplus Heat from Biogas Marselisborg WWTP
Construction costs US 180,000 Annual
Income (sale) US 71,000 ROI lt 1
year CO2 Reduction 322 ton/year Excess
heat sales of 2.5 GWh/year (2013)
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Struvite - From Problem to RessourceRecovery
of a valuable phosphorous resource
The problem

• Gray irritating material in pipes, digesters
• and sludge treatment processes

Mg2 HPO42- NH4 6H2O ?
MgNH4PO4,6H2O H magnesium phosphorous
ammonium water ? struvite acid
The resource
12.6 P, 5.6 N, 10 Mg a premium
fertilizer!
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Full Scale Struvite Plant Aaby WWTP

• Capacity of plant
• Capacity 2600 gallons reject/h
• 3-400 kg Struvite/day
• 2 reactors
• Benefits of P-recovery
• Fewer problems with dewatering equipment
• Savings on chemicals for P-removal in main
  process
• Less sludge production.
• Less polymer consumption
• Less Electricity for nitrification (less NH4)
• More biogas
• Increase in plant capacity
• ROI 5-7 years

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Where are we going?
Consulate General of Denmark in Chicago
US - WWTP
Our focus

• Sharing and exchanging best practices and
  knowledge on technical solutions as related to
  the entire Water Cycle.
• Looking for US Champions who want to enter into a
  mutual knowledge sharing exchange and have an
  ongoing working relationship with our Water
  Specialist/WTA

Next step

• Workshop at Downers Grove, Nick Maninga on
  January 27, 2015
• Fact finding trip to Denmark

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Wastewater, a Resource not a Burden!
Thank you for your attention.