Aeration in wastewater treatment

1. BLOWING AWAY YOUR BUGS
Brian Gongol
DJ Gongol & Associates, Inc.
April 12, 2016
Iowa AWWA Short Course
Ankeny, Iowa

2. Aeration

3. Part 1: Purposes

4. Biological treatment

5. Temperature mixing

6. Seasonal inversion

7. Odor control

8. Mixing effects

9. Solids settling

10. Ice prevention

11. Part 2: History

12. Early human history: Stale or stagnant water

13. Biological treatment emerged in late 1800s

14. 1882: Original study of aerating sewage

15. Trickling filters, septic tanks prevalent

16. 1893: First studies suggesting activated sludge

17. 1914: Activated sludge first defined

18. 1913-1915: First patents granted (US and UK)

19. 1915-1916: First full-scale US activated sludge plants

20. 1920s: The rise of lawsuits

21. 1936-1943: Tapered, step, and modified aeration

22. 1972: Federal Water Pollution Control Act Amendments

23. 1977: Clean Water Act

24. Part 3: Mechanical aeration

25. Cascades (waterfalls)

26. Trickling filter

27. Fountain aerator

28. Splasher - high-speed

29. Splasher - low-speed

30. RBC

31. Solar-powered mixers

32. Part 4: Forced air - coarse bubbles

33. Perforated hose and static tube

34. Wideband

35. Duckbill check valve diffusers

36. Coarse discs

37. Coarse bubble caps

38. Jet

39. Part 5: Forced air fine bubbles

40. Ceramic discs

41. Membrane discs

42. Membrane tubes

43. Floating aspiration

44. Submerged aspiration

45. Unconventional membranes

46. Micro and nano-bubbles

47. Part 6: Oxygen transfer

48. Pure oxygen versus air

49. OTE

50. Bubble size

51. Distance traveled

52. Part 7: Accessories and considerations

53. Grit and solids settling

54. Baffles to extend treatment

55. Solids uptake into wideband diffusers

56. Cleaning

57. Fouling

58. Creep

59. Heat

60. Minerals

61. Materials of construction

62. Non-sticking surfaces

63. Power failure

64. Integral check valves

65. Part 8: Locations

66. Pump station wetwells

67. Storage/equalization basins

68. Pretreatment

69. Biological treatment

70. Clarification/dissolved-air floatation

71. Polishing

72. Aerobic sludge digestion

73. To recap
 Aeration serves a variety of purposes
 The obvious ones have been known for quite some time
 The biological treatment uses are only about a century old
 Mechanical aeration faces serious limitations
 Coarse bubbles can get some work done
 Broad agreement surrounds the advantages of small bubbles

74. Questions?
 Thank you for coming!

75. Thank you for your attention!
 Contact us anytime with
questions
 Brian Gongol
 DJ Gongol & Associates
 515-223-4144
 info@djgongol.com

76. References
 Valuable historical details obtained from "Reflections on
Seven Decades of AS History" by James E. Alleman and TBS
Prakasam, Journal of the Water Pollution Control Federation
(1985)
 Supplemental historical details from "History of Activated
Sludge", Conference of the International Water Association
(2014)
 Some illustrations courtesy of the respective manufacturers
(RWL Water and SSI Aeration)
 All other photos are original work by and copyright reserved
to Brian Gongol