Membrane based fluid treatment systems

• US 7,186,344 B2
• Filed: 04/17/2002
• Issued: 03/06/2007
• Est. Priority Date: 04/17/2002
• Status: Expired due to Fees

• Current Assignee: Watervisions International Incorporated
• Original Assignee: Water Visions International
• Inventors: Hughes, Kenneth D.
• Primary Examiner(s): Fortuna; Ana M.
• Application Number:
  US10/125,073
• Publication Number:
  US 20030196955A1
• Time in Patent Office: 1,784 Days
• Field of Search: 210/679, 210/638, 210/258, 210650-652, 210/501.2, 210/502.1, 210/660, 210/641, 210/195.2, 210/257.2, 210/663, 210/266, 210/282, 210/670, 210/681
• US Class Current: 210/652
• 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 organic and inorganic chemical contaminants, microbiological contaminants, or combinations thereof to reduce the concentration of these contaminants comprising:

passing the fluid stream through a pretreatment module to reduce both soluble and insoluble contaminants and to convert soluble contaminants into other forms present therein, the pretreatment module including a filtering medium which comprises bone charcoal or bauxite;

recovering from the pretreatment module a treated stream;

passing the treated stream through a membrane module to remove additional insoluble and soluble chemical and microbiological contaminants present therein; and

recovering from the membrane module a membrane permeate,

wherein at least one of the contaminants removed by the process is a manganese containing oxidizer or a peroxide containing oxidizer.

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

passing the fluid stream through a pretreatment module to reduce both soluble and insoluble contaminants and to convert soluble contaminants into other forms present therein, the pretreatment module including a filtering medium which comprises bone charcoal or bauxite;

recovering from the pretreatment module a treated stream;

passing the treated stream though a membrane module to remove additional insoluble and soluble chemical and microbiological contaminants present therein; and

recovering from the membrane module a membrane permeate,

wherein at least one of the contaminants reduced by the process is a sulfur containing compound or a hydrocarbon.

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

passing the fluid stream through a pretreatment module to reduce both soluble and insoluble contaminants and to convert soluble contaminants into other forms present therein, the pretreatment module including a filtering medium which comprises bone charcoal or bauxite;

recovering from the pretreatment module a treated stream;

passing the treated stream through the membrane module to remove additional insoluble and soluble chemical and microbiological contaminants present therein; and

recovering from the membrane module a membrane permeate,

wherein at least one of the contaminants reduced by the process is hydrogen sulfide.

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

passing the fluid stream through a pretreatment module to reduce both soluble and insoluble contaminants and to convert soluble contaminants into other forms present therein, the pretreatment module including a filtering medium which comprises rises bone charcoal or bauxite fixed within a binder matrix;

recovering from the pretreatment module a treated stream;

passing the treated stream though a membrane module to remove additional insoluble and soluble chemical and microbiological contaminants present therein;

recovering from the membrane module a membrane permeate; and

adjusting the pH of the fluid stream before the pretreatment module.

5. 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 through a pretreatment module to reduce both soluble and insoluble contaminants and to convert soluble contaminants into other forms present therein, the pretreatment module including a filtering medium which comprises bone charcoal or bauxite;

recovering from the pretreatment module a treated stream;

passing the treated stream through a membrane module to remove additional insoluble and soluble chemical and microbiological contaminants present therein; and

recovering from the membrane module a membrane permeate,

wherein at least one of the contaminants are reduced by the pretreatment module to an oxidation state to effectuate removal of said at least one of the contaminants by the membrane module; and

wherein (i) the contaminant removed is a chlorine-containing oxidizer, a manganese-containing oxidizer, or a peroxide-containing oxidizer, or (ii) the contaminant reduced is a sulfur-containing compound or a hydrocarbon.

6. The process of claim 5, wherein the filtering medium is bone charcoal.

7. The process of claim 5, wherein the filtering medium is bauxite.

8. The process of claim 5 further comprising passing the membrane permeate through the post-treatment module to reduce soluble contaminants which pass through the membrane module, and to recover from the post-treatment module a post-treatment stream which may be used.

9. The process of claim 8, further comprising the step of backwashing with a recharge solution the pretreatment module, the post-treatment module, the membrane module, or a combination thereof.

10. The method of claim 8, wherein the post-treatment module comprises a filtering medium comprising bone charcoal, one or more of the individual components contained in bone charcoal, bauxite, or one or more of the individual components contained in bauxite.

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

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

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

14. The process of claim 13, further comprising adjusting the pH of the fluid stream between the recycle treatment module and the membrane module.

15. The process of claim 13, further comprising adjusting the pH of the fluid stream between the recycle treatment module and the pretreatment module.

16. The process of claim 5, wherein the contaminant removed is a metal.

17. The process of claim 16, wherein the metal is arsenic.

18. The process of claim 17, wherein the arsenic metal is in a trivalent state.

19. The process of claim 17, wherein the arsenic metal is in a pentavalent state.

20. The process of claim 16, wherein the metal is iron.

21. The process of claim 20, wherein the iron metal is in the divalent state.

22. The process of claim 16, wherein the metal is cadmium.

23. The process of claim 5, wherein the contaminant removed is a chlorine containing oxidizer.

24. The process of claim 5, wherein the contaminant removed is a manganese containing oxidizer.

25. The process of claim 5, wherein the contaminant removed is a peroxide containing oxidizer.

26. The process of claim 5, wherein the contaminant reduced is a sulfur containing compound.

27. The process of claim 26, wherein the contaminant reduced is hydrogen sulfide.

28. The process of claim 5, wherein the contaminant reduced is a hydrocarbon.

29. The process of claim 28, wherein said hydrocarbon is from a petroleum-related waste stream.

30. The process of claim 5 further comprising adjusting the pH of the fluid stream before the pretreatment module.

31. The process of claim 5 further comprising adjusting the pH of the fluid stream between the pretreatment module and the membrane module.

32. The process of claim 5 further comprising passing the fluid stream through at least one turbidity reduction filter prior to the pretreatment module.

33. The process of claim 5, wherein the membrane module comprises a microfiltration membrane.

34. The process of claim 5, wherein the membrane module comprises a nanofiltration membrane.

35. The process of claim 5, wherein the membrane module comprises an ultrafiltration membrane.

36. The process of claim 5, wherein the membrane module comprises a reverse osmosis membrane.

37. The process of claim 5, further comprising passing the membrane permeate through at least one additional membrane module, wherein the membrane modules are arranged in series.

38. The process of claim 5, further comprising passing the treated stream through at least one additional membrane module, wherein the membrane modules are arranged in parallel.

39. The process of claim 5 further comprising cleaning or modifying the membrane module with a membrane cleaning or modifying solution.

40. The process of claim 5, wherein the pretreatment module further contains oxides of iron, titanium, or silicon.

41. The process of claim 5, wherein the pretreatment module further contains aluminosilicates and zeolites.

42. The process of claim 5, wherein the pretreatment module further contains calcium phosphates.

43. The process of claim 42, wherein the pretreatment module further contains calcium phosphate in an apatite structure.

44. The process of claim 5, wherein the pretreatment module further contains calcium carbonates.

45. The process of claim 5, wherein the pretreatment module further contains one or more of the individual components contained in phosphate rock.

46. The process of claim 5, wherein the pretreatment module further contains manganese containing silicates.

47. The process of claim 5, wherein the pretreatment module further contains iron phosphates, iron carbonates, iron silicates or combinations thereof.

48. The process of claim 5, wherein the pretreatment module further contains zirconium phosphates.

49. The process of claim 5, wherein the pretreatment module further contains activated carbon as a component of a composite matrix.

50. The process of claim 5, wherein the pretreatment module further contains copper metal or an alloy of copper metal.

51. The process of claim 5, wherein the pretreatment module further contains iron metal or an alloy of iron metal.

52. The process of claim 5 further comprising the step of backwashing the pretreatment module, the membrane module, or a combination thereof to extend the life thereof using a reservoir or fluid stream originating from a low-pressure side of the pretreatment module, the membrane module, or a combination thereof.

53. The process of claim 5, wherein the fluid treatment system is used in residential point of use applications.

54. The process of claim 5, wherein the fluid treatment system is used in residential point of entry applications.

55. The process of claim 5, wherein the fluid treatment system is used in institutional, military, or industrial applications.

56. The process of claim 5, wherein the fluid treatment system is used in pharmaceutical applications.

57. The process of claim 5, wherein the fluid treatment system is used in medical applications.

58. The process of claim 5, wherein the fluid treatment system is used in semiconductor applications.

59. The process of claim 5, further comprising the step of cleaning or recharging the pretreatment module, the membrane module or a combination thereof by passing a module cleaning solution or module regenerative solution through the pretreatment module, the membrane module, or a combination thereof.

60. The process of claim 5 further comprising sterilizing the pretreatment module, the membrane module, or a combination thereof.

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

passing the fluid stream through a pretreatment module to reduce both soluble and insoluble contaminants and to convert soluble contaminants into other forms present therein, the pretreatment module including a filtering medium which comprises bone charcoal, bauxite, or one or more components of bone charcoal or bauxite;

recovering from the pretreatment module a treated stream;

passing the treated stream through a membrane module to remove additional insoluble and soluble chemical and microbiological contaminants present therein; and

recovering from the membrane module a membrane permeate,

wherein at least one of the contaminants are reduced by the pretreatment module to an oxidation state to effectuate removal of said at least one of the contaminants by the membrane module; and

wherein the pretreatment module further includes a calcium phosphate, a calcium carbonate, at least one component of phosphate rock, a manganese-containing silicate, an iron phosphate, an iron carbonate, an iron silicate, a zirconium phosphate, a copper metal, an alloy of copper metal, an iron metal, an alloy of iron metal, or a combination thereof.

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

passing the fluid stream through a pretreatment module to reduce both soluble and insoluble contaminants and to convert soluble contaminants into other forms present therein, the pretreatment module including a filtering medium which comprises bone charcoal or bauxite fixed within binder matrix;

recovering from the pretreatment module a treated stream;

passing the treated stream through a membrane module to remove additional insoluble and soluble chemical and microbiological contaminants present therein; and

recovering from the membrane module a membrane permeate,

wherein at least one of the contaminants are reduced by the pretreatment module to an oxidation state to effectuate removal of said at least one of the contaminants by the membrane module; and

wherein the pretreatment module contains a prefilter sheet material.

63. The process of claim 62, wherein the prefilter sheet material has a pore size distribution greater than that of the composite filtering medium.

64. The process of claim 62, wherein the prefilter sheet material has a pore size distribution smaller than that of the composite.