Biological method of waste water treatment

• US 5,582,732 A
• Filed: 05/19/1995
• Issued: 12/10/1996
• Est. Priority Date: 03/31/1995
• Status: Expired due to Fees

• Current Assignee: Aquatex Corporation
• Original Assignee: Aquatex Corporation
• Inventors: Lourenco, Jose J., Mao, Huazhong
• Primary Examiner(s): Wyse, Thomas S.
• Application Number:
  US08/444,751
• Time in Patent Office: 571 Days
• Field of Search: 210/603, 210/605, 210/610-612, 210/614-618, 210/630, 210/631, 210/903, 210/906, 210/908, 210/909
• US Class Current: 210/603
• CPC Class Codes: C02F 3/06 using submerged filters
• CPC Class Codes: C02F 3/101 Arranged-type packing, e.g. stacks, arrays
• CPC Class Codes: C02F 3/34 characterised by the microorganisms used
• CPC Class Codes: Y02W 10/10 Biological treatment of water, waste water, or sewage
• CPC Class Codes: Y10S 210/903 Nitrogenous

Abstract

A method of treating waste water is described. Firstly, providing specially acclimatized microbial consortia with relatively low sensitivity to changes in pH and changes in temperature, such that the microbial consortia is capable of metabolizing contaminants efficiently within a predetermined broad pH range and broad temperature range. Secondly, maintain the microbial consortia in a space limited and a substrate limited mode within an immobilized bioreactor operating within the predetermined pH range and the predetermined temperature range. Thirdly, introduce waste water with liquified insoluble organic contaminants into the immobilized bioreactor. The organic contaminants are metabolized by the microbial consortia working under space limited and substrate limited conditions, thereby treating the waste water with a minimal sludge production rate.

Claims

1. A method of treating waste water, comprising the step of:

firstly, providing specially acclimatized microbial consortia with relatively low sensitivity to changes in pH and changes in temperature, such that the microbial consortia is capable of metabolizing contaminants efficiently within a predetermined broad pH range and broad temperature range;

secondly, maintaining the microbial consortia in a space limited mode within an immobilized bioreactor operating within the predetermined pH range and the predetermined temperature range; and

thirdly, introducing waste water with liquified insoluble organic contaminants into the immobilized bioreactor, the organic contaminants being metabolized by the microbial consortia working under space limited conditions, thereby treating the waste water with a minimal sludge production rate.

2. The method of treating waste water as defined in claim 1, the microbial consortia being in both a space limited and a substrate limited mode.

3. The method of treating waste water as defined in claim 2, the microbial consortia being capable of metabolizing contaminants efficiently within a broad pH range from 5.1 to 9.0.

4. The method of treating waste water as defined in claim 3, having an anaerobic immobilized bioreactor, an anoxic immobilized bioreactor, an aerobic immobilized bioreactor, and a nitrification immobilized bioreactor arranged in a desired series order to accommodate a continuous flow of waste water.

5. The method of treating waste water as defined in claim 1, the microbial consortia being capable of metabolizing contaminants efficiently at pH levels of less than 7.0.

6. The method of treating waste water as defined in claim 1, the microbial consortia being capable of metabolizing contaminants efficiently within a temperature range from 10 degrees to 38 degrees centigrade.

7. A method of treating waste water, comprising the steps of:

firstly, providing specially acclimatized microbial consortia with relatively low sensitivity to changes in pH and changes in temperature, such that the microbial consortia is capable of metabolizing contaminants efficiently within a predetermined broad pH range and broad temperature range;

secondly, providing at least one immobilized bioreactor with a substantially vertical plug flow pattern and operating the immobilized bioreactor within the predetermined pH range and the predetermined temperature range;

thirdly, immobilizing the microbial consortia within pores of an immobilized media positioned within the at least one immobilized bioreactor; and

fourthly, introducing waste water with liquified organic contaminants into the at least one immobilized bioreactor, the flow through the at least one immobilized bioreactor sheering microbial consortia from an exposed surface of the immobilized media to maintain a biofilm thickness of less then 500 microns, thereby maintaining the microbial consortia in a space limited and a substrate limited mode, the organic contaminants being metabolized by the space limited and substrate limited microbial consortia thereby treating the waste water with a minimal sludge production rate.

8. The method of waste water treatment as defined in claim 7, having a two stage nitrification immobilized bioreactor with a first plug flow stage and a second continuously mixing stage.

9. The method of waste water treatment as defined in claim 7, having NO3 and NO2 produced within the nitrification immobilized bioreactor routed to the anoxic immobilized bioreactor to be converted into N2, nitrogen gas and NO2.

10. The method of waste water treatment as defined in claim 7, having the microbial consortia acclimatized to metabolize ammonia efficiently independent of Ph.

11. The method of waste water treatment as defined in claim 10, having a porosity of 45 pores per inch.

12. The method of waste water treatment as defined in claim 7, having a porosity of between 20 and 45 pores per inch in the immobilized media of the immobilized bioreactor.

13. The method of waste water treatment as defined in claim 7, having a porosity of between 30 and 60 pores per inch in the immobilized media of the nitrification immobilized bioreactor.

14. The method of waste water treatment as defined in claim 13, having the stream exiting the polishing immobilized bioreactor introduced into an ozone disinfection tank, thereby destroying any microorganisms remaining in the treated waste water stream.

15. The method of waste water treatment as defined in claim 14, having an angle of 45 degrees.

16. The method of waste water treatment as defined in claim 7, having the stream leaving the nitrification immobilized bioreactor introduced into a polishing immobilized bioreactor with a substantially vertical flow pattern and a heterogeneous microbial consortia, the flow through the polishing immobilized bioreactor sheering microbial consortia from exposed surfaces of the immobilized media to maintain a biofilm thickness of less then 500 microns, thereby maintaining the microbial consortia in a space limiting and substrate limiting mode, the organic contaminants being metabolized by the space limited and substrate limited microbial consortia thereby treating the waste water with a minimal sludge production rate.

17. The method of waste water treatment as defined in claim 7, having waste gases removed from each of the immobilized bioreactors to a common conduit leading to an ozone injector that eliminates unpleasant odours.

18. The method of waste water treatment as defined in claim 7, having a plug flow pattern with angles of between 30 and 60 degrees.

19. The method of waste water treatment as defined in claim 7, having a dissolved oxygen concentration of greater than four milligrams per litre in the aerobic immobilization bioreactor and the nitrification immobilization bioreactor.

20. A method of treating waste water, comprising the steps of:

firstly, providing specially acclimatized microbial consortia with relatively low sensitivity to changes in pH and changes in temperature, such that the microbial consortia is capable of surviving within a predetermined broad pH range and broad temperature range;

secondly, placing in series order to accommodate a continuous flow of waste water an anaerobic immobilized bioreactor, an anoxic immobilized bioreactor, an aerobic immobilized bioreactor, and a nitrification immobilized bioreactor, all of the immobilized bioreactors having a substantially vertical plug flow pattern and operating within the predetermined pH range and the predetermined temperature range;

thirdly, immobilizing the microbial consortia within pores of immobilized media positioned within each of the immobilized bioreactors;

fourthly, introducing a waste water stream with liquified organic contaminants into the anaerobic immobilized bioreactor in a substantially vertical plug flow pattern, the flow through the anaerobic immobilized bioreactor sheering microbial consortia from an exposed surface of the immobilized media to maintain a biofilm thickness of less then 500 microns, thereby maintaining the microbial consortia in a space limiting or substrate limiting mode, the organic contaminants being metabolized by the space limited and substrate limited microbial consortia thereby treating the waste water with a minimal sludge production rate;

fifthly, introducing the stream leaving anaerobic immobilized bioreactor into the anoxic immobilized bioreactor along with a carbon energy source in a substantially vertical plug flow pattern, the flow through the anoxic immobilized bioreactor sheering microbial consortia from an exposed surface of the immobilized media to maintain a biofilm thickness of less then 500 microns, thereby maintaining the microbial consortia in a space limiting and substrate limiting mode, the organic contaminants being metabolized by the space limited and substrate limited microbial consortia thereby treating the waste water with a minimal sludge production rate;

sixthly, introducing the stream leaving the anoxic immobilized bioreactor into the aerobic immobilized bioreactor along with at least 4 milligrams per litre of dissolved oxygen gas in a substantially vertical continuously stirred flow pattern, the high ratio of dissolved oxygen to contaminant solute concentration facilitating a portion of the microbial consortia going into an endogenous state, the flow through the aerobic immobilized bioreactor sheering microbial consortia from an exposed surface of the immobilized media to maintain a biofilm thickness of less then 500 microns, thereby maintaining the microbial consortia in a space limiting and substrate limiting mode, the organic contaminants being metabolized by the space limited and substrate limited microbial consortia thereby treating the waste water with a minimal sludge production rate;

seventhly, introducing the stream leaving the aerobic immobilized bioreactor into the nitrification immobilized bioreactor along with at least four milligrams per litre of dissolved oxygen gas in a substantially vertical flow pattern, the high dissolved oxygen to contaminant solute concentration resulting in a portion of the microbial consortia going into an endogenous state, the flow through the nitrification immobilized bioreactor sheering microbial consortia from an exposed surface of the immobilized media to maintain a biofilm thickness of less then 500 microns, thereby maintaining the microbial consortia in a space limiting and substrate limiting mode, the organic contaminants being metabolized by the space limited and substrate limited microbial consortia thereby treating the waste water with a minimal sludge production rate.