Process for providing oxygen to a liquid

• US 7,699,985 B2
• Filed: 12/03/2007
• Issued: 04/20/2010
• Est. Priority Date: 02/13/2003
• Status: Expired due to Term

• Current Assignee: Zenon Technology Partnership
• Original Assignee: Zenon Technology Partnership
• Inventors: Behmann, Henry, Cote, Pierre Lucien, Husain, Hidayat
• Primary Examiner(s): Barry; Chester T
• Application Number:
  US11/949,383
• Publication Number:
  US 20080110827A1
• Time in Patent Office: 869 Days
• Field of Search: 261/122.1, 261/122.2, 210/615, 210/620
• US Class Current: 210/615
• 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 63/034 Lumen open in more than two directions
• CPC Class Codes: B01D 63/04 comprising multiple hollow fibre assemblies
• CPC Class Codes: B01D 69/084 Undulated fibres
• CPC Class Codes: B01F 33/4062 with means for modifying the gas pressure or for supplying gas at different pressures or in different volumes at different parts of the bottom
• CPC Class Codes: C02F 2103/005 Black water originating from toilets
• CPC Class Codes: C02F 2103/008 Originating from marine vessels, ships and boats, e.g. bilge water or ballast water
• CPC Class Codes: C02F 3/102 Permeable membranes
• CPC Class Codes: C02F 3/103 Textile-type packing
• CPC Class Codes: C02F 3/208 Membrane aeration C02F3/201 takes precedence
• CPC Class Codes: C02F 3/30 Aerobic and anaerobic processes
• 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 fibers, for example, made from melt spun thermoplastic polymers treated after spinning to increase their permeability to oxygen, used, for example, 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 fibers. Various reactors and processes, for example to treat wastewater, using such modules are described. In one process, oxygen travels through fibers, optionally through an attached biofilm, to oxygenate surrounding water. Mechanical, chemical and biological methods, for example endogenous respiration, are used to control the thickness of the biofilm.

Claims

1. A process for treating a liquid comprising the steps of:

(a) providing an apparatus having one or more dense or semi-porous membrane walls, the wall(s) each having an inner surface and an outer surface;

(b) contacting the outer surface(s) of the wall(s) with the liquid;

(c)growing a biofilm on the outer surface(s); and

(d) providing an oxygen-bearing gas to the inner surface(s) of the wall(s), oxygen from the gas traveling through the wall(s) to the outer surface(s), through the biofilm and into the liquid in an amount effective to oxygenate the liquid.

2. The process of claim 1 further comprising maintaining the biofilm under endogenous respiration.

3. The process of claim 1 further comprising performing nitrification in the biofilm.

4. The process of claim 1 wherein the biofilm has a thickness of at least 20 microns.

5. The process of claim 1 wherein the biofilm performs one or more of

(a) nitrification (removal of ammonia);

and,

(b) removal of COD.

6. The process of claim 1 further comprising maintaining the liquid at a low soluble COD concentration and air scrubbing the biofilm to maintain the biofilm under a certain thickness.

7. A process for treating a liquid comprising the steps of:

(a) providing an apparatus having one or more dense or semi-porous membrane walls, the wall(s) each having an inner surface and an outer surface;

(b) contacting the outer surface(s) of the wall(s) with the liquid; and

(c) providing an oxygen-bearing gas to the inner surface(s) of the wall(s), oxygen from the gas traveling through the wall(s) to the outer surface(s), through a biofilm on the outer surface(s), and into the liquid;

wherein the liquid is water within an aerobic suspended growth bioreactor, and the oxygen traveling through the wall(s) to the outer surface(s), through the biofilm on the outer surface(s), and into the liquid supplies at least 50% of a total bioreactor oxygen demand.