Wastewater, a Resource not a

Burden!

Flemming B Møller Senior Technical Advisor,

Project Manager

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

Flemming B Moller

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

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 !

•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

Agenda.

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.

Reality – where Does the Energy GoElectrical Power Consumption

Aeration 37 %

6

Energy Neutrality And Beyond

The Development in electricy consumption – Marselisborg RA

New Sandfilter+ 1000 kWh/d

Process Optimizing

New Blower

Average 24 – hour electricity consumption

Total reduction achieved 27%

Energy Balance - Power Self Sufficiency %

%

Introduction – Marselisborg WWTP

Energy Savings – Power Production

Optimization of N-removal and Power Consumption

%

Set Point

DOAmmoniumNitrate

ABS HST Compressor

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

15

Specific Energy Consumption – New Blower (HST Compressor)

0,014 kWh/Nm3

Kapselblæsere, Nøgletal (Egå, Viby og Åby): 0,019-0,023 kWh/Nm3Positive displacement blower, Key figures (Egå, Viby og Åby): 0,019-0,023 kWh/Nm3

Sludge Balances and Control of Aerobic Sludge Age

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%

18

Surplus Heat from Biogas – Marselisborg WWTP

Construction costs: US$ 180,000

Annual Income (sale): US$ 71,000

ROI: < 1 year

CO2 Reduction: 322 ton/year

Excess heat sales of 2.5 GWh/year (2013)

19

Struvite - From Problem to RessourceRecovery of a valuable phosphorous resource• Gray irritating material in pipes, digesters

and sludge treatment processes

Mg2+ + HPO42-+ NH4

+ + 6H2O → MgNH4PO4,6H2O + H+

magnesium +phosphorous +ammonium + water → struvite + acid

12.6 % P, 5.6 % N, 10 % Mg

a premium fertilizer!

The problem

The resource

Full Scale Struvite Plant Aaby WWTPCapacity 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

21

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

Consulate General of Denmark in Chicago

Where are we going?

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

Wastewater, a Resource not a Burden!Wastewater, a Resource not a Burden!

Thank you for your attention.