Treatment Facility Technologies and Costs for Phosphorus Removal

1. Treatment Facility Technologies and Costs for Phosphorus Removal

2. Topics Covered • Technologies • Disc Filtration • Ballasted Setting • Continuous BackWash Filter • Membranes • Levels of Treatment • Costs • Sizing

3. Disc filter Applications • Effluent Filtration • Water Re-use • Phosphorus Reduction • CSO/SSO

4. DisC Filter operation • Gravity Flow • Partially Submerged • Stationary Filter Discs • Automatic Operation • Continuous Operation

5. DISC FILTER INSTALLATION (Concrete) Access platform elevation Outlet weir Inlet trough Emergency bypass channel Bypass weir Filter effluent channel Influent channel FLOW

6. DISC FILTER Performance (Turbidity)

7. Oconomowoc, WI

8. Oconomowoc, WI TERTIARY POLISHING

9. Oconomowoc, WI TERTIARY POLISHING

10. Oconomowoc, WI TERTIARY POLISHING

11. Phosphorus Levels & Technology • Coagulant 1.0 mg/l 0.50 – 0.30 mg/l 0.30 – 0.20 mg/l < 0.20 mg/l • Multipoint coagulant addition • Assisted with biological • Coagulant • Biological • Coagulant and Polymer ? • Disc Filter • Coagulant • Biological • Coagulant and Polymer • Disc Filter

12. VFD VFD Coagulant Polymer Solids Static Mixer Filtered Effluent Coagulation (3 - 5 min HRT) Flocculation (3 - 6 min HRT) Disc filter Coagulation/Flocculation prior to Filtration Secondary Clarifier Effluent

13. Pilot Study - Clinton, MA (March/April 2011) • Disc Filtration used for total Phosphorus removal - <0.10 mg/L • Normal and Stressed Conditions • Ferric Chloride and Aluminum Sulfate Used

14. Clinton, MA

15. Ballasted Settling – Process ChemistryMicrosand

16. Ballasted Settling – Floc Particle ~ 150 µm Floc

17. VFD VFD Coagulant Polymer Solids Static Mixer Flocculation (3 - 6 min HRT) Disc filter Coagulation (3 - 5 min HRT) Ballasted Settling – Coagulation/Flocculation Secondary Clarifier Effluent

18. Ballasted Settling – Process Schematic • High Rate Clarifier, • 30-50 gpm/ft2

19. Ballasted Settling -HydrocycloneSludgeSeparation

20. Ballasted Settling – Caldwell, ID Pilot Study ResultsExtended Run with Ferric Chloride • Bio-P Selector Bypassed • Influent Total Phosphorus Increased from 0.3 mg/l to 3mg/l • Achieve 70 ppb Effluent Total Phosphorus

21. Continuous BackWash Filter • Regenerative Adsorptive Column • Coagulant Ferric Sulfate or Ferric Chloride

22. Continuous Backwash Filter Biological System Secondary Clarifier Back Wash Filter Headworks RAS WAS Optional 2nd Pass Digester Solids Dewatering Reject Recycle

24. CONTINUOUSBACKWASH FILTER Clean Water Rapid Conditioning Zone Secondary Effluent Reject Stream HFO Sand Grain Water PO43- Particles

25. Continuous backWash Filter Fe • Hydrous Ferric Oxide-Coated Sand • Images from scanning electron microscopy • X-ray Flourescence P

26. CONTINUOUS BACKWASH FILTER

27. Membrane Bioreactor Treated water Sludge Water/Air Flow Membrane Aeration MEMBRANES

28. MEMBRANES Process

29. 1.5 1.5 Membrane PVDF Membrane ) 2 / m Choice “A” Type B 1 1 12 東レ 東レ BF014 BF014 Number of pore (10 0.5 0.5 クボタ クボタ 0 0 0 0 0.2 0.2 0.4 0.4 0.6 0.6 0.8 0.8 Pore diameter (micron) Pore diameter (micron) MEMBRANES 3.0 micrometer 3.0 micrometer

30. MEMBRANES FLUX & PRESSUREComparison of Immersed Membrane Modules Type B Flat Sheet MLSS: 10,000 mg/l

31. FLAT SHEET MEMBRANE • 0.08 mm nominal pore size • ~15 ft2 (~1.4m2) per element • 5.3’ High x 1.7’ Wide x 0.04’ Thick

32. Relaxation (Intermittent Filtration) 10 minute cycle: 9 minutes filtration followed by 1 minute relaxation and suspension of permeate (aeration is continuous) Filtration 1 min 1 min 9 mins 9 mins 9 mins 1 min Scour Aeration MEMBRANE Operating Modes:Filtration and Relaxation Mode

33. Membrane Tanks - MBR

34. MBR - Bermuda • Operating since Oct 2009 • 0.25 MGD • Gravity Flow Permeate • Membrane Thickening

35. Membrane Tanks - MBR • Two tanks – Five modules each • Membrane thickening: One tank, one module

36. LEVELs of Treatment Approximate • Disc Filtration > 0.15 mg/L TP • Ballasted Settling > 0.06 mg/L TP • Continuous Back Wash Filter < 0.06 mg/L TP • Membranes < 0.06 mg/L TP

37. WHICH TECHNOLOGY?

38. Equipment Costs for Phosphorus Removal

39. WWTF Facility Upgrade Costs for Phosphorus Removal

40. O & M Costs Membranes

41. Equipment Sizing • Not always peak hour flow • 365 Day Average, Total P Limit • Blending Potential

42. Disc Filtration – Take Aways • Tertiary Polishing Phosphorus Treatment • Phosphorus Reduction – Need Coagulation or Flocculation • In-pipe dosing not sufficient • Mixing, energy critical • Floc needs structural integrity • Use existing tankage (if possible)

43. Ballasted Settling - Takeaways • Enhanced Floc Formation • Shorter HRT Higher Loading Rate • Mixing energy critical • Use existing tankage (if possible)

44. Continuous Backwash Filters - Takeaways • Regenerative Adsorption Process • Hydrous Ferric Oxide-Coated Sand • Multiple Passes for Additional Treatment • Lower Coagulant Dose • Reject Stream • Possible Re-use Fe P

45. MEMBRANE - Takeaways • High level of treatment • P • Water reuse • Micropollutants • Energy intensive • High Capital Cost • Compact footprint • Membrane fouling critical • Aeration • Intermittent relaxation • Backwashing • Citric Acid

46. Questions?