ROTATING BIOLOGICAL CONTACTOR (RBC) PROCESS

1. ROTATING BIOLOGICAL CONTACTOR (RBC) PROCESS Prepared By Michigan Department of Environmental Quality Operator Training and Certification Unit

2. ROTATING BIOLOGICAL CONTACTORS Contactors Primary Treatment Secondary Clarifier Effluent Influent Solids Removal

3. RBC Secondary Treatment Rotating Plastic Media Provides Large Surface Area 1.6 rpm 40 % Submerged Microorganisms “Treat” the Wastewater by Using Organics

4. New Cells NH3 CO2 H2O Wastewater Slime Layer Cell Membrane Food Storage Oxygen Enzymes (Absorption) Adsorbed Particle Soluble Organics

5. Oxygen Organics Liquid Film Biomass Media (disc) Oxygen

6. Liquid Film Liquid Film Random Continuous Sloughing OXYGEN Organics BIOMASS Media

7. RBC Flow Scheme INFLUENT Primary Treatment Rotating Biological Contactors Pretreatment Disinfection Secondary Clarifiers EFFLUENT Solids Handling

8. ADVANTAGES OF RBC PROCESS Simple Operation Low Energy Requirements Nitrification Few Nuisances Wide Flow Range Large Biological Population

11. ADVANTAGES OF RBC PROCESS Simple Operation Low Energy Requirements Nitrification Few Nuisances Wide Flow Range Large Biological Population Handles Shock Loads Low Head Loss

12. DISADVANTAGES OF RBC PROCESS Limited Controls Enclosures Limited Experience and Training

13. RBC COMPONENTS CONTACTOR TANK CLARIFIER

14. RBC COMPONENTS CONTACTOR Discs Shaft Individual Disc

15. Media “High Density” Polyethylene Carbon Black

16. Media – Irregular Surface Maintain Spacing Increases Rigidity Increases Surface Area Increases Contact Time

17. Media – Irregular Surface “Corrugated”

18. Media – Irregular Surface “Dimpled”

20. “Random Fill”

21. Media 1 Inch BIOMASS

22. 10 to 12 Ft Diameter ~ 25 Ft Long

23. Media High Density Standard Density 1 inch ¾ inch

25. Shaft Square Shaft

27. Round Shaft

28. Octagonal Shaft

30. Bearings “Floating” Self-aligning

31. Bearings

32. Shaft Bearing Load Cell Coupling for Hydraulic Pump Load Cells

33. Load Cells Purpose: Determine Weight of Contactor to Determine Amount (Thickness) of Biomass

34. Drive Systems - Chain

35. Drive Systems - Direct

36. Drive Systems - Air Air Cups Air Header Air Diffusers

37. Drive Systems - Air Air Cups Rotation Air Header

38. Drive Systems - Air

39. Drive Systems - Air

40. Drive Systems - Combination

41. Containment

42. Containment Just Large Enough Good Contact Minimal Short Circuiting Good Mixing

43. “Train” FLOW FLOW RBC Systems Usually More Than One Contactor with Flow Progressing in Series in a “Train”

44. Flow Schemes Parallel to Shaft Direction of Flow Perpendicular to Shaft Contactors May be Arranged With Flow Either Parallel or Perpendicular to Shafts

45. Influent Effluent Baffles “Train” Small Systems – Train May be One Contactor with Separations and Baffles

46. Larger Systems – Contactors are Set in Series in Separate Tanks or in One Tank With Enclosure Effluent Influent Baffles

47. Baffles

48. Train Baffles FLOW FLOW Baffles Separate Each Contactor, Dividing the Flow in the Train Into Separate Complete Mix Zones of Treatment

49. Train Baffles FLOW Each Zone of Treatment is Called a “Stage”

50. Train Baffles FLOW 5 Stages (Zones of Treatment)