Grease and scum removal in a filtration apparatus comprising a membrane bioreactor and a treatment vessel for digesting organic materials

• US 7,329,344 B2
• Filed: 12/21/2005
• Issued: 02/12/2008
• Est. Priority Date: 12/22/2004
• Status: Expired due to Fees

• Current Assignee: Evoqua Water Technologies LLC
• Original Assignee: Siemen Water Technologies Corporation (Siemens AG)
• Inventors: Elefritz, Robert, Jordan, Edward John
• Primary Examiner(s): Barry; Chester T.
• Application Number:
  US11/314,793
• Publication Number:
  US 20070084791A1
• Time in Patent Office: 783 Days
• Field of Search: 210/194, 210/195.1, 210/196, 210/248, 210/310
• US Class Current: 210/195.1
• CPC Class Codes: B01D 2315/06 Submerged-type; Immersion type
• CPC Class Codes: B01D 2315/12 Feed-and-bleed systems
• CPC Class Codes: B01D 2321/2033 dynamically
• CPC Class Codes: B01D 61/145 Ultrafiltration
• CPC Class Codes: B01D 61/18 Apparatus therefor
• CPC Class Codes: B01D 63/02 Hollow fibre modules
• CPC Class Codes: B01D 63/024 with a single potted end
• CPC Class Codes: B01D 65/08 Prevention of membrane fouling or of concentration polarisation
• CPC Class Codes: C02F 3/1268 Membrane bioreactor systems
• CPC Class Codes: Y02W 10/10 Biological treatment of water, waste water, or sewage

Abstract

The invention relates to a membrane bioreactor process combined with an advanced biological sludge digestion process that provides significant improvements in sludge digestion by reducing the costs and resources required for disposing of digested sludge. The offline treatment vessel is used to solubilize the organic material by operating in a very low oxygen environment. Digested process fluid is transferred back to the membrane bioreactor. The processes and apparatus substantially reduce the production of waste sludge. The device includes one or more weirs operable to remove grease and scum.

Claims

1. A membrane bioreactor for wastewater purification comprising:

a biological purification system;

an immersed membrane purification system;

a downstream channel for fluid flow from the biological purification system to the membrane purification system;

a return channel for fluid flow from the membrane purification system to the biological purification system;

an overflow weir on the downstream channel to remove overflow and floating impurities from the downstream channel.

2. A membrane bioreactor according to claim 1 further including a second return channel to remove floating impurities from the membrane purification system for return to the biological purification system.

3. A membrane bioreactor according to claim 1 further including a take-off channel to remove floating impurities from the membrane purification system for disposal.

4. A membrane bioreactor according to claim 1 wherein the weir is located within the biological purification system.

5. A membrane bioreactor according to claim 1 wherein the weir is located within the membrane purification system.

6. A membrane bioreactor according to claim 1 wherein the weir is located between within the biological purification system and membrane purification system.

7. A membrane bioreactor according to claim 1 wherein the weir is located external to the biological purification system and membrane purification system.

22. A membrane bioreactor according to claim 1 comprising a tank containing the immersed membranes.

23. A membrane bioreactor according to claim 22 wherein the immersed membranes are a plurality of hollow fibre membranes, bundled into vertically arrayed membrane modules.

24. A membrane bioreactor according to claim 23 comprising a mixed liquor feed channel from the biological purification system which enters the membrane modules at the base.

25. A membrane bioreactor according to claim 22 including a frit at the base of the membrane modules to introduce air bubbles to scour and fluidise solid contaminants that may be present on the outer surface of the membrane.

26. A membrane bioreactor according to claim 22 wherein flow in the return channel from the membrane filtration unit is fed by the fluid from the immersed membranes.

27. A membrane bioreactor according to claim 26 wherein the return channel is positioned at a height above the height of the immersed membrane.

8. A membrane bioreactor for wastewater purification comprising:

a biological purification system;

an immersed membrane purification system;

a downstream channel for fluid flow from the biological purification system to the membrane purification system; and

an overflow weir on the downstream channel to remove overflow and floating impurities from the downstream channel.

9. A membrane bioreactor according to claim 8 further including a second return channel to remove floating impurities from the membrane purification system for return to the biological purification system.

10. A membrane bioreactor according to claim 8 further including a take-off channel to remove floating impurities from the membrane purification system for disposal.

11. A membrane bioreactor according to claim 8 wherein the weir is located within the biological purification system.

12. A membrane bioreactor according to claim 8 wherein the weir is located within the membrane purification system.

13. A membrane bioreactor according to claim 8 wherein the weir is located between within the biological purification system and membrane purification system.

14. A membrane bioreactor according to claim 8 wherein the weir is located external to the biological purification system and membrane purification system.

15. A membrane bioreactor for wastewater purification comprising:

a biological purification system;

an immersed membrane purification system;

a return channel for fluid flow from the membrane purification system to the biological purification system;

an overflow weir on the return channel to remove overflow and floating impurities from the membrane purification system.

16. A membrane bioreactor according to claim 15 further including a second return channel to remove floating impurities from the membrane purification system for return to the biological purification system.

17. A membrane bioreactor according to claim 15 further including a take-off channel to remove floating impurities from the membrane purification system for disposal.

18. A membrane bioreactor according to claim 15 wherein the weir is located within the biological purification system.

19. A membrane bioreactor according to claim 15 wherein the weir is located within the membrane purification system.

20. A membrane bioreactor according to claim 15 wherein the weir is located between within the biological purification system and membrane purification system.

21. A membrane bioreactor according to claim 15 wherein the weir is located external to the biological purification system and membrane purification system.