Wastewater treatment method and apparatus, biosolids-based food additive, and business application

• US 7,931,806 B2
• Filed: 10/31/2008
• Issued: 04/26/2011
• Est. Priority Date: 11/01/2007
• Status: Expired due to Fees

• Current Assignee: Procell Investments Limited
• Original Assignee: Oberon FRM Incorporated
• Inventors: Terry, Seth Sprague, Logan, Andrew J., Swenson, Randy
• Primary Examiner(s): Barry; Chester T
• Application Number:
  US12/262,971
• Publication Number:
  US 20090114602A1
• Time in Patent Office: 907 Days
• Field of Search: 210/609, 210/220, 210610-614, 210/138, 210/143, 210150-151, 435/71.1, 435/804, 705/1.1, 705/308
• US Class Current: 210/609
• CPC Class Codes: A23J 1/001 from waste materials, e.g. kitchen waste
• CPC Class Codes: A23J 3/04 Animal proteins
• CPC Class Codes: C02F 2103/32 from the food or foodstuff industry, e.g. brewery waste waters
• CPC Class Codes: C02F 3/12 Activated sludge processes
• CPC Class Codes: C02F 3/34 characterised by the microorganisms used
• CPC Class Codes: G06Q 10/30 Administration of product recycling or disposal
• 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: Y02W 10/37 using solar energy
• CPC Class Codes: Y02W 90/00 Enabling technologies or technologies with a potential or indirect contribution to greenhouse gas [GHG] emissions mitigation
• CPC Class Codes: Y10S 435/804 Single cell protein

Abstract

The present invention is directed to processes and business methods and wastewater treatment units for converting the waterborne residuals from wastewater generated by food processing plants into an ingredient suitable for use in animal feeds. The ingredient produced by the processes of the present invention has a high protein content and can be used as a replacement for conventional sources of animal feed protein such as fish meal.

Claims

1. A process comprising:

adding an aqueous waste stream comprising metabolizable components to a growth vessel containing at least one bacterial culture, at a first flow rate;

allowing the bacteria of the at least one bacterial culture to grow in the growth vessel by metabolizing at least a portion of the metabolizable components of the aqueous waste stream, thereby forming a bacterial suspension in an aqueous bulk liquid, wherein the aqueous bulk liquid is depleted of metabolizable components relative to the aqueous waste stream;

separating a portion of the bacterial suspension from the aqueous bulk liquid, thereby forming a bacterial mass;

removing the bacterial mass at a second flow rate;

removing a portion of the aqueous bulk liquid at a third flow rate, wherein the aqueous bulk liquid is substantially free of total suspended solids;

adjusting the second flow rate to provide a MCRT of the bacteria of no more than about 8 days; and

drying the removed bacterial mass within a time period whereby MWRT−

MCRT≦

about 2 days.

2. The process of claim 1, wherein MCRT is no more than about 6 days.

3. The process of claim 1, wherein MCRT is no more than about 6 days, and MWRT−

MCRT≦

1 day.

4. The process of claim 1, wherein said separating is carried out by gravity separating, dissolved air flotation, or by a membrane bioreactor.

5. The process of claim 1, wherein the aqueous waste stream added to the growth vessel comprises dissolved and/or suspended metabolizable food or beverage byproducts from a food processing plant producing human or animal food.

6. The process of claim 1, wherein said drying is carried out for a time period of about one day or less at a temperature of about 65°

-95°

C.

7. The process of claim 3, wherein said drying is carried out at a temperature of about 80°

C. for a time period of one day or less.

8. The process of claim 1, wherein said drying is carried out within a time period whereby MWRT−

MCRT≦

1 day.

9. The process of claim 1, wherein the at least one bacterial culture comprises bacteria selected from the group consisting of genetically modified bacteria, Micrococci, Bacilli, Flavobacteria, methanogens, Pseudomona, Nitrosomona, Nitrobacteri, nitrifying bacteria, aerobic heterotrophs, and combinations thereof.

10. The process of claim 1, further comprising dewatering the removed bacterial mass prior to said drying.

11. The process of claim 1, wherein nutrients selected from the group consisting of macronutrients, micronutrients, vitamins, amino acids, and combinations thereof are added to the bacterial growth vessel.

12. The process of claim 11, wherein the macronutrients are biologically assimilable sources of C, H, O, N, and P.

13. The process of claim 11, wherein the vitamins are selected from the group consisting of vitamin A, vitamin B₁, vitamin B₂, vitamin B₃, vitamin B₅, vitamin B₆, vitamin B₇, vitamin B₉, vitamin B₁₂, vitamin C, vitamin D, vitamin E, and vitamin K.

14. The process of claim 1, wherein the aqueous bulk liquid has a BOD ranging from about 200 to about 200,000 mg/L.

15. The process of claim 1, wherein the dried bacterial mass has a ratio of protein/ash of about 6.0/1 to 8.0/1.

16. The process of claim 1, wherein the dried bacterial mass is suitable for use as a feed for animals used for human consumption and complies with the requirements of the American Association of Feed Control Officials Official Publication (2007).

17. The process of claim 1, wherein said process is a continuous process.

18. The process of claim 1, wherein said process is a batch process.

19. The process of claim 1, wherein the MCRT is about 1 to 6 days.

20. The process of claim 1, further comprising:

receiving a first signal, the first signal associated with a quantity of a first portion of the bacterial suspension, the first portion of the bacterial suspension contained within a first portion of an aqueous bulk liquid;

calculating a total cell mass of the bacterial suspension based on at least the first signal;

the quantity of bacterial mass removed at the second flow rate;

calculating the MCRT of the bacteria based on the total cell mass of the bacterial suspension and the second signal; and

adjusting the second flow rate such that the MCRT of the bacteria is within a predetermined range.

21. The process of claim 20, wherein the first signal is associated with a concentration of the first portion of the bacterial suspension within the first portion of the aqueous bulk liquid.

22. The process of claim 20, wherein:

the first portion of the aqueous bulk liquid is within a waste stream entering the growth vessel; and

the first signal is associated with a flow rate of the waste stream entering growth vessel.

23. The process of claim 20, wherein the second signal is associated with at least one of a concentration of the bacterial mass removed and the second flow rate.

24. The process of claim 20, wherein the predetermined range is between approximately two days and approximately eight days.

25. The process of claim 20, wherein the adjusting includes:

calculating a pump control signal based on the calculated MCRT of the bacteria and a target MCRT within the predetermined range; and

transmitting a pump control signal to a variable-speed pump disposed within a flow path of the bacterial mass being removed at a second flow rate.

26. The process of claim 20, further comprising:

adjusting the second flow rate such that the MWRT of the bacterial mass is within a predetermined range.

27. A method, comprising:

calculating a processing cost associated with reducing a biochemical oxygen demand level of an aqueous waste stream from an input biochemical oxygen demand level to an output biochemical oxygen demand level;

calculating a recovery value associated with a bacterial mass removed from the aqueous waste stream when the biochemical oxygen demand level of the aqueous waste stream is reduced from the input biochemical oxygen demand level to the output biochemical oxygen demand level; and

adjusting automatically a contract price associated with reducing the biochemical oxygen demand level of the aqueous waste stream based on at least the processing cost and the recovery value.

28. The method of claim 27, further comprising:

generating an invoice reflecting the adjusted contract price.

29. The method of claim 27, wherein at least one of the calculating the processing cost and the calculating the recovery value is performed substantially continuously when the biochemical oxygen demand level of the aqueous waste stream is being reduced.

30. The method of claim 27, wherein calculating the processing cost includes:

receiving a first signal associated with a flow rate of the aqueous waste stream into a waste water treatment system;

receiving a second signal associated with the input biochemical oxygen demand level of the aqueous waste stream;

calculating a plurality of processing costs as a function of time, each processing cost from the plurality of processing costs being calculated based on the first signal and the second signal; and

calculating an arithmetic mean of the plurality of processing costs for predetermined time period.

31. The method of claim 27, wherein the calculating the recovery cost includes:

receiving a signal associated with a flow rate of the bacterial mass removed from the aqueous waste stream;

receiving a signal associated with a protein content of the bacterial mass removed from the aqueous waste stream; and

receiving input associated with a market price for animal feed.

32. The method of claim 27, wherein at least one of the calculating the processing cost and the calculating the recovery value includes calculating a mean cell retention time of the bacterial mass within a waste water treatment system.

33. The method of claim 27, wherein at least one of the calculating the processing cost and the calculating the recovery value includes calculating a mean waste residence time of the bacterial mass mean.

34. A method, comprising:

calculating a processing cost associated with a process of reducing a biochemical oxygen demand level of an aqueous waste stream from an input biochemical oxygen demand level to an output biochemical oxygen demand level;

calculating a recovery value associated with a bacterial mass removed from the aqueous waste stream during the process; and

adjusting automatically a portion of the process based on at least the processing cost and the recovery value.

35. The method of claim 34, wherein the adjusting includes:

adjusting a target mean cell retention time of the bacterial mass within a waste water treatment system; and

transmitting a pump control signal to a variable-speed pump disposed within the waste water treatment system.

36. The method of claim 34, wherein the adjusting includes:

adjusting a target mean waste retention time of the bacterial mass within a waste water treatment system; and

transmitting a pump control signal to a variable-speed pump disposed within the waste water treatment system.

37. A wastewater treatment unit comprising:

a growth vessel;

means for adding an aqueous waste stream comprising metabolizable components to the growth vessel;

at least one bacterial culture in the growth vessel, which metabolizes at least a portion of the metabolizable components of the aqueous waste stream, thereby forming a bacterial suspension in an aqueous bulk liquid, wherein the aqueous bulk liquid is depleted of metabolizable components relative to the aqueous waste stream;

means for aerating the bacterial suspension and aqueous bulk liquid in the growth vessel;

means for separating a portion of the bacterial suspension from the aqueous bulk liquid, thereby forming a bacterial mass;

means for removing the bacterial mass from the wastewater treatment unit;

means for adjusting the rate at which the bacterial mass is removed to provide a MCRT of the bacteria in the wastewater treatment unit of no more than about 8 days;

means for removing a portion of the aqueous bulk liquid from the wastewater treatment unit, wherein said aqueous bulk liquid is substantially free of total suspended solids;

means for drying the removed bacterial mass; and

means for adjusting the time period in which the removed bacterial mass is dried whereby MWRT−

MCRT≦

about 2 days.

38. The wastewater treatment unit of claim 37, wherein the means for separating is selected from the group consisting of a clarifier vessel, a dissolved air flotation vessel, or a membrane bioreactor, wherein the clarifier vessel, dissolved air flotation vessel, and membrane bioreactor are connected to the growth vessel with means for recycling the bacterial suspension in the aqueous bulk liquid between the growth vessel and the clarifier vessel, dissolved air flotation vessel, or membrane bioreactor.

39. The wastewater treatment unit of claim 37, further comprising means for dewatering disposed between the means for removing the bacterial mass and the means for drying the removed bacterial mass.

40. The wastewater treatment unit of claim 37, wherein said at least one bacterial culture comprises bacteria selected from the group consisting of genetically modified bacteria, Micrococci, Bacilli, Flavobacteria, methanogens, Pseudomonas, Nitrosomonas, Nitrobacteria, nitrifying bacteria, aerobic heterotrophs, and combinations thereof.

41. A method comprising:

receiving an aqueous waste stream from a food and/or beverage processing plant comprising dissolved or suspended metabolizable food and/or beverage byproducts with BOD levels of ≧

about 100 mg/L;

adding the aqueous waste stream comprising metabolizable components to a growth vessel containing at least one bacterial culture, at a first flow rate;

allowing the bacteria of the at least one bacterial culture to grow in the growth vessel by metabolizing at least a portion of the metabolizable components of the aqueous waste stream, thereby forming a bacterial suspension in an aqueous bulk liquid, wherein the aqueous bulk liquid is depleted of metabolizable components relative to the aqueous waste stream;

separating a portion of the bacterial suspension from the aqueous bulk liquid, thereby fowling a bacterial mass;

removing the bacterial mass at a second flow rate;

removing a portion of the aqueous bulk liquid at a third flow rate, wherein the aqueous bulk liquid is substantially free of total suspended solids and has a BOD within permitted levels;

adjusting the second flow rate to provide a MCRT of the bacteria of no more than about 8 days; and

drying the removed bacterial mass within a time period whereby MWRT−

MCRT≦

about 2 days;

providing the dried bacterial mass as a protein source for animal feed.

42. The method of claim 41, wherein said dried bacterial mass is provided to animal feed producers as a replacement for fish meal in animal feeds.

43. The method of claim 41, wherein said the bacterial mass is dried to a solids content of 80% or more and is provided as an animal feed ingredient.

44. The method of claim 41, further comprising:

determining the protein content of the dried bacterial mass,

diverting bacterial mass having a protein content >

40% to a storage vessel;

diverting bacterial mass having a protein content <

40% to a waste vessel; and

providing the bacterial mass with a protein content >

40% as a protein source for animal feed.

45. A composition comprising:

a dried and deactivated bacterial mass comprising a mixture of bacteria, wherein the true protein content is at least about 50%, wherein the dried bacterial mass is suitable for use as a feed for animals used for human consumption and complies with the requirements of the American Association of Feed Control Officials Official Publication (2007), wherein the amino acid levels, total amino acid levels, and crude protein levels are at least those in the following table;

46. A composition comprising:

a dried and deactivated bacterial mass comprising a mixture of bacteria, wherein the true protein content is at least about 50%, wherein the dried bacterial mass is suitable for use as a feed for animals used for human consumption and complies with the requirements of the American Association of Feed Control Officials Official Publication (2007), wherein the amino acid levels are at least those in the following table;