WASTEWATER TREATMENT TRENDS IN THE 21ST CENTURY

1. The Kappe Lecture Stevens Institute of Technology September 21, 2013 George Tchobanoglous Department of Civil and Environmental Engineering University of California, Davis WASTEWATER TREATMENT TRENDS IN THE 21ST CENTURY

2. Topics Part-1 Some Global Trends Part-2 Uncontrollable Events and Unintended Consequences Part-3 Future Trends, Challenges, and Opportunities

3. Part-1 Some Global Trends that will Impact Wastewater Treatment • Population Demographics Impact of urban spread Urbanization along coastal areas • Climate Change (wetter/dryer) Sea level rise Changing weather patterns • Aging infrastructure

4. Impactof Urbanization on Plant Siting and Reuse

5. Impact of Coastal Population Demographicson Reuse, Hyperion WWTP, Los Angeles, CA

6. Urbanization Along Coastal Areas • By 2030, 60-70 percent of world’s population will live near a coastal region • Withdrawing water from inland areas, transporting it to urban population centers, treating it, using it once, and discharging it to the coastal waters is unsustainable.

7. Impact of Sea Level Rise onWastewater Management Infrastructure

8. Aging Infrastructure Challenges • Aging wastewater infrastructure (typical age 75 years) in large cities over 100 years old with excessive exfiltration • Flowrateswill continue to decrease resulting in: • Increased corrosion • Most conventional gravity sewer design equations no longer suitable • Increased mass concentration loading factors have impacted wastewater treatment facilities

9. Part-2 Impact of Uncontrolled Events and Unintended Consequences • Uncontrollable events Natural disasters (e.g., storm surges) Impact of climate change on rainfall intensity Power and chemical costs • Unintended consequences Treatment plant siting (considered previously) Water conservation Treatment plant design/energy usage Excess treatment capacity (e.g., tankage)

10. Impact of Storm Surges onWastewater Management Infrastructure

11. Impact of Climate Change on Rainfall Intensity and Operation of WWTP

12. Unintended Consequence of Sea LevelRise on StormwaterCollectionSystem Courtesy City of San Francisco

13. Unintended Consequence of Sea Level Rise onStormwater Collection System Courtesy City of San Francisco

14. Impact of Decreasing Flowrates on Operation of Collection Systems and WWTPs

15. Impact of Water Conservation and Drought:Solids Deposition, H2S Formation, and Downstream Corrosion due to Reduced Flows

16. At $0.03/kWh energy efficiency was not an Issue. • Older Treat. Plant Design - Little Concern for: • The use of resources, • The consumption of energy, • Long-term sustainability, and • The carbon footprint

17. Energy Usage in BiologicalTreatment (e.g., activated Sludge)

18. Impacts of Water Conservation on Treatment Plant Capacity

19. Part-3 Future Trends, Challenges,and Opportunities • Paradigm shift in view of wastewater • Alternative collection systems • Energy recovery from wastewater • Enhanced preliminary and pretreatment • Urine separation • Direct and indirect potable reuse • Integrated wastewater management

20. New View of Wastewater: A Paradigm Shift for the 21st Century WASTEWATER is a RENEWABLESOURCE of ENERGY (heat and chemical), RESOURCES, POTABLE WATER

21. Alternative Collection Systems for Source Separated Resource Streams

22. ENERGY RECOVERY FROM WASTEWATER

23. Energy Content of Wastewater Heat energy Specific heat of water = 4.1816 J/g •°C at 20°C Chemical oxygen demand(COD) C7.9H13O3.7NS0.04 C7.9H13NO3.7 + 8.55O2→ 7.9CO2 + NH3+ 5H2O Chemical energy (Channiwala,1992) HHV (MJ/kg) = 34.91 C + 117.83 H - 10.34 O - 1.51 N + 10.05 S - 2.11A

24. Energy Content of Wastewater

25. Required and Available Energy for Wastewater Treatment, Exclusive of Heat Energy • Energy required for secondary wastewater treatment • 1,200 to 2,400 MJ/1000 m3 • Energy available in wastewater for treatment (assume COD = 500 g/m3) • Q = [500 kg COD/1000 m3) (1000 m3) (13 MJ/ kg COD) • =6,000 MJ/1000 m3 • Energy available in wastewater is 2 to 4 times the amount required for treatment

26. Heat Recovery from Wastewater SOURCE : City of Vancouver, Sustainability website retrieved from http://vancouver.ca/sustainability/neuTechnology.htm FALSE CREEK ENERGY CENTER

27. Wastewater and Food Waste Management Options

28. ENHANCED PRELIMINARY TREATMENT Grit and Grease Removal

29. Settling Characteristics of Gritin Wastewater Collection Systems

30. ENHANCED PRETREATMENT

31. Alternative Technologies for Primary Treatment and Energy Recovery

32. ALTERNATIVE TREATMENT TECHNOLOGIES

33. Alternative Treatment Process Flow Diagrams Based on Primary Effluent Filtration

34. Membrane Filtration without Biological Treatment

35. New Biological Treatment Processes Ambient Temperature Anammox Process

36. Alternative Wastewater TreatmentWithout Biological Treatment Energyand product recovery Solids processing

37. RETURN FLOW TREATMENT, FLOW AND LOAD EQUALIZATION, AND RESOURCE RECOVERY

38. Return FlowsTreatment, Flow Equalization, or Offsite Processing

39. Phosphorus Recovery as Struvite(magnesium ammonium phosphate hexahydrate)

40. URINE SEPARATION

41. Examples of Urine Separation Fixtures

42. Nutrients and Trace Organics in Domestic Wastewater: A Case for Urine Separation Source: Jönsson et al.(2000) Recycling Source Separated Human Urine.

43. Potential Impacts of Urine Separation On Biological Wastewater Treatment

44. Urine Utilization in Indoor Wetland System Near Os, Norway

45. Nutrient Separation, Storage, and RecoveryFrom Individual Residence

46. DIRECT AND INDIRECT POTABLE REUSE

47. Recycling Through Direct and Indirect Potable Reuse

48. Indirect and Direct Potable Reuse OCWD Windhoek, Namibia ~30% San Diego, CA (Proposed), Singapore, Australia

49. Typical Flow Diagram for the Production of Purified Water Adapted from OCWD

50. Microfiltration, Cartridge Filters, Reverse Osmosis, and Advanced Treatment (UV), OCWD