Membrane based fluid treatment systems

• US 20030196955A1
• Filed: 04/17/2002
• Published: 10/23/2003
• Est. Priority Date: 04/17/2002
• Status: Active Grant

• Current Assignee: Watervisions International Incorporated
• Original Assignee: Watervisions International Incorporated
• Inventors: Hughes, Kenneth D.
• Granted Patent: US 7,186,344 B2
• Time in Patent Office: Days
• US Class Current: 210/650
• CPC Class Codes: B01D 2311/04 Specific process operations in the feed stream; Feed pretreatment
• CPC Class Codes: B01D 2311/12 Addition of chemical agents
• CPC Class Codes: B01D 2311/2684 Electrochemical processes
• CPC Class Codes: B01D 2311/2688 Biological processes
• CPC Class Codes: B01D 61/025 Reverse osmosis; Hyperfiltration
• CPC Class Codes: B01D 61/027 Nanofiltration
• CPC Class Codes: B01D 61/04 Feed pretreatment
• CPC Class Codes: B01D 61/145 Ultrafiltration
• CPC Class Codes: B01D 61/147 Microfiltration
• CPC Class Codes: B01D 61/16 Feed pretreatment
• CPC Class Codes: C02F 1/281 using inorganic sorbents
• CPC Class Codes: C02F 1/283 using coal, charred products, or inorganic mixtures containing them
• CPC Class Codes: C02F 1/441 by reverse osmosis
• CPC Class Codes: C02F 1/444 by ultrafiltration or microfiltration
• CPC Class Codes: C02F 1/66 by neutralisation; pH adjustment for degassing C02F1/20; using ion-exchange C02F1/42; for flocculation or precipitation of suspended impurities C02F1/52; for removing dissolved compounds C02F1/58
• CPC Class Codes: C02F 2101/103 Arsenic compounds
• CPC Class Codes: C02F 2101/203 Iron or iron compound
• CPC Class Codes: C02F 2101/32 Hydrocarbons, e.g. oil

Abstract

A process for removing soluble and insoluble inorganic, organic, and microbiological contaminants from a fluid stream employing a pretreatment module, a post-treatment module, a recycle stream module or any combination thereof, and a membrane module, is provided. The process provided reduces the problems associated with membrane fouling and increases contaminant removal capacity.

Claims

1. A process for treating a fluid stream containing soluble and insoluble inorganic and organic chemical contaminants, microbiological contaminants, or combinations thereof to reduce the concentration of these contaminants comprising:

passing the fluid stream into contact with a high pressure side of a module to reduce both soluble and insoluble contaminants and to convert soluble contaminants into other forms present therein, and to recover from the low pressure side of the module a treated stream; and

passing the fluid stream into contact with a high pressure side of a membrane module to remove additional insoluble and soluble chemical and microbiological contaminants present therein, and to recover from the low pressure side a treated membrane permeate.

2. The process of claim 1, wherein the treatment module is a pretreatment module and the fluid stream passes through the pretreatment module and is then passed through the membrane module.

3. The process of claim 1, wherein the treatment module is a post-treatment module and the fluid stream passes through the membrane module and is then passed through the post-treatment module.

4. The process of claim 1, wherein the treatment module is a pretreatment module and the fluid stream passes through the pretreatment module and is then passed through the membrane module and further comprising a post-treatment module wherein the treated membrane permeate is passed into contact with a high pressure side of the post-treatment module to reduce soluble contaminants which pass through the membrane module, and to recover from the low pressure side of the post-treatment module a post-treatment stream which may be used.

5. The process of claim 1, wherein a membrane concentrate stream is recycled from the high pressure side of the membrane module to the high pressure side of the pre-treatment module.

6. The process of claim 1, wherein a membrane concentrate stream is recycled from the high pressure side of the membrane module to the high pressure side of the membrane module.

7. The process of claim 1, wherein a membrane concentrate stream is recycled from the high pressure side of the membrane module to the high pressure side of a recycle treatment module.

8. The process of claim 1, further comprising the step of passing a recharge solution stream into contact with a high pressure side of a recycle treatment module to recover from the low pressure side a treated recharge stream;

further wherein the treated recharge stream is passed into contact with a high pressure side of a treatment module to back-flush the treatment module to reduce the concentration of both soluble and insoluble contaminants including metals and microbiological contaminants therein, wherein the treatment module may be a pretreatment module, a post-treatment module;

the membrane module, or a combination thereof.

9. The process of claim 1, where the contaminant removed is a metal.

10. The process of claim 9, where the metal is arsenic.

11. The process of claim 10, where the arsenic metal is in a trivalent state.

12. The process of claim 10, where the arsenic metal is in a pentavalent state.

13. The process of claim 9, where the metal is iron.

14. The process of claim 13, where the iron metal is in the divalent state.

15. The process of claim 9, where the metal is cadmium.

16. The process of claim 1, where the contaminant removed is an oxidizer.

17. The process of claim 16, where the contaminant removed is a chlorine containing oxidizer.

18. The process of claim 16, where the contaminant removed is a manganese containing oxidizer.

19. The process of claim 16, where the contaminant removed is a peroxide containing oxidizer.

20. The process of claim 1, where the contaminant reduced is a sulfur containing compound.

21. The process of claim 20, where the contaminant reduced is hydrogen sulfide.

22. The process of claim 1, where the contaminant reduced is a microorganism such as bacteria, virus, cyst, or a combination thereof.

23. The process of claim 1, wherein the contaminant reduced is a biological component of a microorganism such as bacteria, virus, cyst, or a combination thereof.

24. The process of claim 1, wherein the contaminant reduced is a hydrocarbon.

25. The process of claim 24, where the contaminant reduced is a hydrocarbon from a petroleum-related waste stream.

26. The process of claim 1, wherein pH adjustment of the fluid is completed before the treatment module.

27. The process of claim 1, wherein the fluid undergoes pH adjustment between the treatment module and the membrane module.

28. The process of claim 8, wherein the fluid undergoes pH adjustment between the recycle treatment module and the membrane module.

29. The process of claim 8, wherein the fluid undergoes pH adjustment between the recycle treatment module and the treatment module.

30. The process of claim 1, wherein at least one turbidity reduction filter is used prior to the treatment module.

31. The process of claim 1, wherein the membrane comprises a microfiltration membrane.

32. The process of claim 1, wherein the membrane comprises a nanofiltration membrane.

33. The process of claim 1, where the membrane comprises an ultrafiltration membrane.

34. The process of claim 1, where the membrane comprises a reverse osmosis membrane.

35. The process of claim 1, further comprising at least one additional membrane module, wherein the membrane modules are arranged in series.

36. The process of claim 1, further comprising at least one additional membrane module, wherein the membrane modules are arranged in parallel.

37. The process of claim 1, wherein a membrane cleaning or modifying solution is employed.

38. The process of claim 1, wherein the treatment module contains bauxite or components of bauxite.

39. The process of claim 38, wherein the treatment module contains aluminum oxides.

40. The process of claim 38, wherein the treatment module contains oxides of iron, titanium, and silicon.

41. The process of claim 38, wherein the treatment module contains alurninosilicates and zeolites.

42. The process of claim 35, wherein the treatment module contains bone charcoal.

46. The process of claim 42, wherein the treatment module contains calcium carbonates.

47. The process of claim 1, wherein the treatment module contains one or more of the individual components contained in phosphate rock.

48. The process of claim 1, wherein the treatment module contains manganese containing silicates.

49. The process of claim 1, wherein the treatment module contains iron phosphates, iron carbonates, iron silicates or combinations thereof.

50. The process of claim 1, wherein the treatment module contains zirconium phosphates.

51. The process of claim 1, wherein the treatment module contains activated carbon as a component of the composite matrix.

52. The process of claim 1, wherein the treatment module contains copper metal or an alloy of copper metal.

53. The process of claim 1, wherein the treatment module contains iron metal or an alloy of iron metal.

54. The process of claim 1, wherein the treatment module contains a prefilter sheet material.

55. The process of claim 54, where the prefilter sheet material contains a pore size distribution greater than that contained by the composite.

56. The process of claim 54, where the prefilter sheet material contains a pore size distribution smaller than that contained by the composite.

57. The process of claim 1, where the treatment module, the membrane module, or a combination thereof is back-flushed to extend life using a reservoir or fluid stream originating from the low-pressure side of the treatment module, the membrane module, or the combination thereof.

58. The process of claim 1, where the fluid treatment system is used in residential point of use applications.

59. The process of claim 1, where the fluid treatment system is used in residential point of entry applications.

60. The process of claim 1, where the fluid treatment system is used in institutional, military, or industrial applications.

61. The process of claim 1, where the fluid treatment system is used in pharmaceutical applications.

62. The process of claim 1, where the fluid treatment system is used in medical applications.

63. The process of claim 1, where the fluid treatment system is used in semiconductor applications.

64. The process of claim 1, wherein a module cleaning solution or module regenerative solution is used to clean or recharge any combination of the modules employed in the fluid treatment system.

65. The process of claim 1, where the treatment module may be sterilized.

43. The process of claim 43, wherein the treatment module contains one or more of the individual components contained in bone charcoal.

44. The process of claim 43, wherein the treatment module contains calcium phosphates.

45. The process of claim 44, wherein the treatment module contains calcium phosphate in an apatite structure.