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

2. 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 employees209 Annual budget 146 mill USD/year Our vision is to be a leader amongst water companies

3. 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 !

4. 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.

5. 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.

6. Reality – where Does the Energy Go Electrical Power Consumption Aeration 37 % 6

7. Energy Neutrality And Beyond

8. 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%

9. Energy Balance - Power Self Sufficiency % %

10. Introduction – Marselisborg WWTP

12. Energy Savings – Power Production

13. Optimization of N-removal and Power Consumption % Set Point DO Ammonium Nitrate

15. 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

16. Specific Energy Consumption – New Blower (HST Compressor) 0,014 kWh/Nm 3 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

17. Sludge Balances and Control of Aerobic Sludge Age

18. 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

19. 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

20. Struvite - From Problem to Ressource Recovery of a valuable phosphorous resource Gray irritating material in pipes, digesters and sludge treatment processes Mg 2+ + HPO 4 2- + NH 4 + + 6H 2 O → MgNH 4 PO 4,6H 2 O + H + magnesium +phosphorous +ammonium + water → struvite + acid 12.6 % P, 5.6 % N, 10 % Mg a premium fertilizer! The problem The resource

21. 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 21

22. 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

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