Supported biofilm apparatus and process

• US 7,169,295 B2
• Filed: 03/17/2004
• Issued: 01/30/2007
• Est. Priority Date: 02/13/2003
• Status: Active Grant

• Current Assignee: Zenon Technology Partnership
• Original Assignee: Zenon Technology Partnership
• Inventors: Cote, Pierre Lucien, Behmann, Henry, Husain, Hidayat, Towe, Ian Glenn, Pottinger, Ian Alexander
• Primary Examiner(s): Barry; Chester T
• Application Number:
  US10/801,660
• Publication Number:
  US 20040229343A1
• Time in Patent Office: 1,049 Days
• Field of Search: 210/150, 210/615
• US Class Current: 210/150
• CPC Class Codes: B01D 63/02 Hollow fibre modules
• CPC Class Codes: B01D 63/021 Manufacturing thereof
• CPC Class Codes: B01D 63/022 Encapsulating hollow fibres
• CPC Class Codes: B01D 63/0233 forming the bundle
• CPC Class Codes: B01D 63/027 Twinned or braided type modules
• CPC Class Codes: B01D 63/031 Two or more types of hollow fibres within one bundle or within one potting or tube-sheet
• CPC Class Codes: B01D 63/04 comprising multiple hollow fibre assemblies
• CPC Class Codes: B01D 69/084 Undulated fibres
• CPC Class Codes: B01F 23/23124 consisting of flexible porous or perforated material, e.g. fabric
• CPC Class Codes: B01F 23/231245 Fabric in the form of woven, knitted, braided, non-woven or flocculated fibers or filaments
• CPC Class Codes: C02F 1/78 with ozone C02F1/4672 takes precedence
• CPC Class Codes: C02F 2303/20 Prevention of biofouling
• CPC Class Codes: C02F 3/102 Permeable membranes
• CPC Class Codes: C02F 3/103 Textile-type packing
• CPC Class Codes: C02F 3/1273 Submerged membrane bioreactors
• CPC Class Codes: C02F 3/208 Membrane aeration C02F3/201 takes precedence
• CPC Class Codes: C02F 3/302 Nitrification and denitrification treatment C02F3/308 takes precedence
• CPC Class Codes: Y02W 10/10 Biological treatment of water, waste water, or sewage

Abstract

A membrane supported biofilm reactor uses modules having fine, hollow fibres, for example, made from dense wall Poly methylpentene (PMP) used in tows or formed into a fabric. In one module, one or more sheets of the fabric are potted into a module to enable oxygen containing gas to be supplied to the lumens of the hollow fibres. Various reactors and processes, for example to treat wastewater, using such modules are described. Mechanical, chemical and biological methods are used to control the thickness of the biofilm.

Claims

1. An apparatus for supporting a biofilm in a liquid comprising:

a) a plurality of gas permeable hollow fibers, each hollow fiber having a lumen, an outer surface, a first open end and an outside diameter of 100 microns or less; and

,

b) a header, the header having a cavity and a port open to the cavity, wherein the hollow fibers extend from the header, with the outer surfaces of the open ends of the hollow fibers sealed to the header and the lumens of the hollow fibers communicating with the port through the cavity.

2. The apparatus of claim 1 wherein the hollow fibers have a hollow area of 10% of the cross-sectional area of the hollow fibers or more, more preferably 30% of the cross-sectional area of the hollow fibers or more.

3. The apparatus of claim 1 wherein the hollow area is 50% of the cross-sectional area of the hollow fibers or less.

6. The apparatus of claim 1 wherein the hollow fibers have a second end and are between 0.25 meters and 3.0 meters long.

7. The apparatus of claim 6 wherein the hollow fibers have a second end and are between 1.0 meters and 2.0 meters long.

4. An apparatus for supporting a biofilm in a liquid comprising:

a) a plurality of gas permeable hollow fibers, each hollow fiber having a lumen, an outer surface, a first open end, wherein the hollow fibers are non-porous or dense walled; and

,

b) a header, the header having a cavity and a port open to the cavity, wherein the hollow fibers extend from the header, with the outer surfaces of the open ends of the hollow fibers sealed to the header and the lumens of the hollow fibers communicating with the port through the cavity.

5. The apparatus of claim 4 wherein the hollow fibers comprise polymethyl pentene.

8. An apparatus for supporting a biofilm in a liquid comprising:

a) a plurality of gas permeable hollow fibers, each hollow fiber having a lumen, an outer surface, a first open end, the hollow fibers having an outside diameter of 500 microns or less and being arranged into two or more groups of fibers; and

,

b) a header, the header having a cavity and a port open to the cavity, wherein the hollow fibers extend from the header, with the outer surfaces of the open ends of the hollow fibers sealed to the header and the lumens of the hollow fibers communicating with the port through the cavity.

9. The apparatus of claim 8 wherein each of the groups of fibers comprises between 24 and 96 hollow fibers.

10. The apparatus of claim 8 wherein each of the groups of fibers further comprises second fibers that are stronger than the hollow fibers.

11. The apparatus of claim 8 wherein at least one of the groups is a tow of fibers.

12. The apparatus of claim 8 wherein the at least one of the groups is a thread, yarn or twisted fibers.

13. The apparatus of claim 8 wherein the hollow fibers are curled, crimped or undulating along their length.

14. An apparatus for supporting a biofilm in a liquid comprising:

a) a plurality of gas permeable hollow fibers, each hollow fiber having a lumen, an outer surface, a first open end, the hollow fibers extending along their length generally in a first direction;

b) a header, the header having a cavity and a port open to the cavity, wherein the hollow fibers extend from the header, with the outer surfaces of the open ends of the hollow fibers sealed to the header and the lumens of the hollow fibers communicating with the port through the cavity; and

,

c) third fibers extending along their length generally in a second direction, the second perpendicular to the first direction.

15. The apparatus of claim 14 wherein the third fibers and hollow fibers are intertwined.

16. The apparatus of claim 15 wherein the hollow fibers and third fibers form a fabric.

17. The apparatus of claim 16 wherein the fabric is generally continuous across the length of the hollow fibers.

18. The apparatus of claim 16 wherein the fabric extends over a portion of the length of the hollow fibers near their open ends and does not extend over a central portion of the length of the fibers.

19. The apparatus of claim 18 wherein the hollow fibers and third fibers are woven, knitted, stitched or warp knitted together over at least a portion of the length of the hollow fibers.

33. The apparatus of claim 16 wherein the roughness of the fabric is between 0.1 and 2 mm.

20. An apparatus for supporting a biofilm in a liquid comprising:

a) a plurality of gas permeable hollow fibers, each hollow fiber having a lumen, an outer surface, a first open end, a second open end; and

,

b) a first header, the first header having a cavity and a port open to the cavity, wherein the hollow fibers extend from the first header, with the outer surfaces of the open ends of the hollow fibers sealed to the first header and the lumens of the hollow fibers communicating with the port through the cavity.

21. The apparatus of claim 20 wherein the second open ends of the hollow fibers are potted in a second header.

22. The apparatus of claim 21 wherein the second open ends communicate with a second port of the second header through a second cavity of the second header.

23. The apparatus of claim 21 wherein the first header and the second header are spaced apart from each other and the hollow fibers are arranged into one or more flat sheets or generally parallel planar structures extending between the headers.

24. The apparatus of claim 23 wherein the flat sheets or planar structures are generally parallel to each other.

25. One or more of the apparatus of claim 23 wherein adjacent planar structures have a spacing between them of between 2 mm and 20 mm or, more preferably, of between 3 mm and 15 mm.

26. The apparatus of claim 21 wherein the first header and second header are held apart at a distance that applies a tensile force to the hollow fibers.

27. The apparatus of claim 23 further comprising spacers between the flat sheets or planar elements outside of the header.

28. The apparatus of claim 23 wherein the flat sheets or planar structures further comprise a rigid member extending between the headers.

29. An apparatus for supporting a biofilm in a liquid comprising:

a) a plurality of gas permeable hollow fibers, each hollow fiber having a lumen, an outer surface, a first open end; and

,

b) a header, the header having a cavity and a port open to the cavity, wherein the hollow fibers extend from the header, with the outer surfaces of the open ends of the hollow fibers sealed to the header and the lumens of the hollow fibers communicating with the port through the cavity, and wherein the apparatus has a surface area for oxygen transfer to surface area of supported biofilm ratio of about 1.6 or more.

30. The apparatus of claim 29 having a surface area for oxygen transfer to surface area of supported biofilm ratio of about 2 or more.

31. The apparatus of claim 30 having a surface area for oxygen transfer to surface area of supported biofilm ratio of about 5 or more.

32. The apparatus of claim 31 having a surface area for oxygen transfer to surface area of supported biofilm ratio of about 1 or less.

34. A reactor comprising:

a) a tank for holding a liquid to be treated, the tank having an inlet and an outlet;

b) an apparatus for supporting a biofilm in a liquid comprising;

i). a plurality of gas permeable hollow fibers, each hollow fiber having a lumen, an outer surface, a first open end, and

ii). a header, the header having a cavity and a port open to the cavity, wherein the hollow fibers extend from the header, with the outer surfaces of the open ends of the hollow fibers sealed to the header and the lumens of the hollow fibers communicating with the port through the cavity; and

c) a gas delivery system for providing a gas to the port.

35. The reactor of claim 34 further comprising an agitator or aerator adapted to agitate the liquid around the apparatus.

36. The reactor of claim 34 further comprising a chemical injection system for injecting chemicals into either the lumens of the hollow fibers or a part of the reactor in communication with the outer surfaces of the hollow fibers.

37. The reactor of claim 34 having a heater to heat either the gas provided to the port or the liquid held in the tank.

38. A multi-stage reactor having two or more reactors according to claim 34, the outlet of a first reactor connected to the inlet of a second reactor.

39. The multi-stage reactor of claim 38 wherein the first and second reactors are plug flow reactors, batch reactors or continuously stirred reactors.

40. The multi-stage reactor of claim 35 wherein the apparatus of the second reactor has a lower surface area for oxygen transfer to surface area of supported biofilm ratio than the apparatus of the first reactor.

41. The multi-stage reactor of claim 38 wherein the apparatus of the first reactor has a surface area for oxygen transfer to surface area of supported biofilm ratio between of 5 or more and the apparatus of the second reactor has a surface area for oxygen transfer to surface area of supported biofilm ratio of 5 or less.

42. The reactor or multi-stage reactor of claim 34 wherein the reactor(s) have a plurality of the apparatus arranged in parallel between the inlet and outlet.

43. The multi-stage reactor of claim 38 wherein the fibers of the apparatus of the first reactor are formed into a sheet along their entire length while the fibers of the apparatus of the second reactor are unsupported by perpendicular fibers over a portion of their length.