Membrane module for gas transfer and membrane supported biofilm process

• US 6,645,374 B2
• Filed: 02/24/2003
• Issued: 11/11/2003
• Est. Priority Date: 03/08/2000
• Status: Expired due to Term

• Current Assignee: Zenon Environmental Incorporated
• Original Assignee: Zenon Environmental Incorporated
• Inventors: Phagoo, Deonarine, Behmann, Henry, Cote, Pierre, Husain, Hidayat, Pedersen, Steven
• Primary Examiner(s): Prince, Fred G.
• Application Number:
  US10/370,527
• Publication Number:
  US 20030150798A1
• Time in Patent Office: 260 Days
• Field of Search: 210/150, 210/151, 210/195.3, 210/198.1, 210/206, 210/259, 210/903, 210/906
• US Class Current: 210/151
• CPC Class Codes: B01D 2313/14 Specific spacers
• CPC Class Codes: B01D 53/22 by diffusion manufacturing semi-permeable membranes B01D67/00; form, structure or properties of semi-permeable membranes B01D69/00; material for semi-permeable membranes B01D71/00
• CPC Class Codes: B01D 53/85 with gas-solid contact
• CPC Class Codes: B01D 63/06 Tubular membrane modules
• CPC Class Codes: B01D 63/10 Spiral-wound membrane modules
• CPC Class Codes: B01D 63/101 Spiral winding
• CPC Class Codes: C02F 2101/30 Organic compounds
• CPC Class Codes: C02F 3/102 Permeable membranes
• CPC Class Codes: C02F 3/20 using diffusers
• CPC Class Codes: C02F 3/208 Membrane aeration C02F3/201 takes precedence
• CPC Class Codes: C02F 3/2806 Anaerobic processes using solid supports for microorganisms
• CPC Class Codes: C02F 3/30 Aerobic and anaerobic processes
• CPC Class Codes: C02F 3/308 Biological phosphorus removal
• CPC Class Codes: Y02A 50/20 Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
• CPC Class Codes: Y02E 50/30 Fuel from waste, e.g. synthetic alcohol or diesel
• CPC Class Codes: Y02W 10/10 Biological treatment of water, waste water, or sewage
• CPC Class Codes: Y10S 210/903 Nitrogenous
• CPC Class Codes: Y10S 210/906 Phosphorus containing

Abstract

An apparatus to transfer gas to or from a liquid has a flexible and oxygen permeable but liquid water impermeable membrane, a flexible and gas permeable spacer, an inlet conduit, an outlet conduit and a non-rigid restraint system. When used for treating wastewater, an aerobic biofilm is cultured adjacent the planar elements, an anoxic biofilm is cultivated adjacent the aerobic biofilm and the wastewater is maintained in an anaerobic state. A first reactor for treating wastewater has an anaerobic section, a plurality of gas transfer membrane modules, and an aerobic section. A biofilm is cultivated on the surface of the gas transfer membranes in fluid communication with the anaerobic section. Biological reduction of COD, BOD, nitrogen and phosphorous are achieved. In a second reactor, phosphorous is also removed chemically in a precipitation branch.

Claims

1. A reactor for treating wastewater to reduce concentrations of one or more of BOD, COD, nitrogen and phosphorous comprising,

(a) an anaerobic section;

(b) a plurality of gas transfer membrane modules for supporting and oxygenating a biofilm on the surface of the gas transfer membranes, the biofilm being in fluid communication with the anaerobic section and having aerobic and anoxic zones; and

,

(c) an aerobic section in fluid communication with the anaerobic section;

(d) a wastewater inlet; and

,

(e) an outlet

wherein wastewater enters the reactor through the inlet and flows through the reactor so as to be treated in the anaerobic section, the aerobic section and by contact with the biofilm before leaving the reactor through the outlet.

2. The reactor of claim 1 further comprising a liquid-solid separation device between the aerobic section and the outlet.

3. The reactor of claim 2 wherein liquid separated in the liquid-solid separation device flows to the outlet and a portion of a sludge containing solids separated in the liquid-solid separation device is recycled to the reactor.

4. The reactor of claim 1 wherein the gas transfer membrane modules are located within the anaerobic section.

5. The reactor of claim 1 further comprising a precipitation branch having a source of phosphorous precipitating agents and a precipitate separation device, the precipitation branch receiving fluid from the anaerobic section.

6. The reactor of claim 5 wherein the precipitation branch receives fluid from the top of the anaerobic section and the anaerobic section is quiescent from time to time such that the mixed liquor may at least partially settle.

7. A reactor for treating wastewater to reduce concentrations of one or more of BOD, COD, nitrogen and phosphorous comprising,

(a) a first section containing a plurality of gas transfer membrane modules connected to an oxygen source operable to cultivate a biofilm on the surface of the gas transfer membranes having aerobic and anoxic zones while not disturbing an anaerobic condition existing in the first section generally,

(b) a second section having an oxygen source operable to create aerobic conditions in the second section;

(d) a wastewater inlet to the first section;

(e) an outlet from the second section; and

,

(f) a passage from the first section to the second section and a second passage from the second section to the first section,

wherein wastewater enters the reactor through the inlet and flows through the reactor so as to be treated in the anaerobic section, the aerobic section and by contact with the biofilm before leaving the reactor through the outlet.

8. The reactor of claim 7 further comprising a liquid-solid separation device between the second section and the outlet.

9. The reactor of claim 8 wherein liquid separated in the liquid-solid separation device flows to the outlet and a portion of a sludge containing solids separated in the liquid-solid separation device is recycled to the reactor.

10. The reactor of claim 7 further comprising a precipitation branch having a source of phosphorous precipitating agents and a precipitate separation device, the precipitation branch being configured to receive fluid from the anaerobic section.

11. The reactor of claim 10 wherein the precipitation branch is configured to receive fluid from the top of the anaerobic section and the anaerobic section is quiescent from time to time such that the mixed liquor may at least partially settle.