Methods for managing sulfide in wastewater systems

• US 9,067,812 B1
• Filed: 12/05/2014
• Issued: 06/30/2015
• Est. Priority Date: 11/21/2006
• Status: Active Grant

• Current Assignee: Streamline Innovations, Inc.
• Original Assignee: Henry Wilmore Jr. Cox
• Inventors: Cox, Henry Wilmore Jr.
• Primary Examiner(s): JOHNSON, EDWARD M
• Application Number:
  US14/561,537
• Time in Patent Office: 207 Days
• Field of Search: 588/320, 588/315, 588/313, 588/318, 588/405, 423/244.01
• US Class Current: 1/1
• CPC Class Codes: C02F 1/683 by addition of complex-forming compounds
• CPC Class Codes: C02F 1/72 by oxidation C02F1/4672 takes precedence
• CPC Class Codes: C02F 1/725 by catalytic oxidation
• CPC Class Codes: C02F 1/727 using pure oxygen or oxygen rich gas
• CPC Class Codes: C02F 1/74 with air aeration of stretches of water C02F7/00
• CPC Class Codes: C02F 2101/101 Sulfur compounds
• CPC Class Codes: C02F 2209/006 comprising a software program or a logic diagram
• CPC Class Codes: C02F 2209/06 pH
• CPC Class Codes: C02F 2209/15 N03-N
• CPC Class Codes: C02F 2209/26 H2S
• CPC Class Codes: C02F 2209/265 in the gas phase
• CPC Class Codes: C02F 2305/02 Specific form of oxidant
• CPC Class Codes: C02F 2305/026 Fenton's reagent
• CPC Class Codes: C02F 2307/08 Treatment of wastewater in the sewer, e.g. to reduce grease, odour
• CPC Class Codes: C02F 3/30 Aerobic and anaerobic processes
• CPC Class Codes: C02F 3/301 Aerobic and anaerobic treatment in the same reactor
• CPC Class Codes: C02F 3/345 for biological oxidation or reduction of sulfur compounds

Abstract

Certain exemplary embodiments can provide a system, machine, device, manufacture, circuit, composition, and/or user interface adapted for and/or resulting from, and/or a method and/or machine-readable medium comprising machine-implementable instructions for, activities that can comprise and/or relate to, in a treatment zone, reacting an oxygen-comprising gas, one or more selected ferric/ferrous chelates, one or more selected nitrates and/or nitrites, and/or anaerobic wastewater.

Claims

1. A method comprising:

in a treatment zone of a manmade container, reacting one or more selected ferric/ferrous chelates, an anaerobic aqueous solution, and an oxygen-comprising gas and/or one or more selected nitrates and/or nitrites,

wherein;

a mass-to-mass ratio of oxygen in the oxygen-comprising gas when entering the treatment zone to available sulfide in the anaerobic aqueous solution when entering the treatment zone is at least approximately 1.5 and less than approximately 3.0; and

when entering the treatment zone, a concentration of the one or more selected ferric/ferrous chelates is in a range of approximately 0.004 M per 1.0 M of sulfide to approximately 0.02 M per 1.0 M of sulfide.

2. The method of claim 1, further comprising:

introducing the one or more selected ferric/ferrous chelates into the treatment zone.

3. The method of claim 1, further comprising:

mixing the one or more selected ferric/ferrous chelates with the anaerobic aqueous solution.

4. The method of claim 1, further comprising:

introducing the anaerobic aqueous solution into the treatment zone.

5. The method of claim 1, further comprising:

flowing the anaerobic aqueous solution through the treatment zone.

6. The method of claim 1, further comprising:

injecting the oxygen-comprising gas into the anaerobic aqueous solution.

7. The method of claim 1, further comprising:

diffusing the oxygen-comprising gas into the anaerobic aqueous solution.

8. The method of claim 1, further comprising:

contacting the oxygen-comprising gas with the anaerobic aqueous solution for at least approximately 3 minutes in the treatment zone.

9. The method of claim 1, further comprising:

introducing the one or more selected nitrates and/or nitrites into the treatment zone during the reacting.

10. The method of claim 1, further comprising:

introducing the one or more selected nitrates and/or nitrites into the treatment zone during the reacting, the one or more selected nitrates and/or nitrites comprising a nitrate salt and/or a nitrite salt.

11. The method of claim 1, further comprising:

mixing the one or more nitrates and/or nitrites with the anaerobic aqueous solution.

12. The method of claim 1, further comprising:

oxidizing any of the one or more selected ferric/ferrous chelates that are in a ferrous state to a ferric state.

13. The method of claim 1, further comprising:

reducing any of the one or more selected ferric/ferrous chelates that are in a ferric state to a ferrous state.

14. The method of claim 1, further comprising:

within the treatment zone, initiating a repeating oxidation-reduction cycle that comprises;

oxidizing any of the one or more selected ferric/ferrous chelates that are in a ferrous state to a ferric state; and

reducing any of the one or more selected ferric/ferrous chelates that are in a ferric state to a ferrous state.

15. The method of claim 1, further comprising:

via the reacting, converting available sulfides in the anaerobic aqueous solution to sulfur oxides.

16. The method of claim 1, wherein:

the one or more selected ferric/ferrous chelates are one or more ferro aminocarboxylates.

17. The method of claim 1, wherein:

the one or more selected ferric/ferrous chelates are selected from ferric/ferrous MGDA, ferric/ferrous EDTA, ferric/ferrous HEIDA ferric/ferrous NTA, and ferric/ferrous gluconate.

18. The method of claim 1, wherein:

the one or more selected ferric/ferrous chelates is ferric/ferrous MGDA.

19. The method of claim 1, wherein:

the one or more selected ferric/ferrous chelates is ferric/ferrous gluconate.

20. The method of claim 1, wherein:

the one or more selected nitrates and/or nitrites, when within the treatment zone, is maintained at a concentration of nitrate in a molar ratio of approximately 3.5 M to approximately 4.5 M per 1.0 M of sulfide.

21. The method of claim 1, wherein:

the anaerobic aqueous solution comprises an oxidant.

22. The method of claim 1, wherein:

a pH of the anaerobic aqueous solution when prior to entering the treatment zone is within a range of approximately 6.0 to approximately 8.5.

23. The method of claim 1, wherein:

the oxygen-comprising gas is substantially pure oxygen.

24. The method of claim 1, wherein:

the oxygen-comprising gas is compressed air.

25. The method of claim 1, wherein:

a mass-to-mass ratio of oxygen in the oxygen-comprising gas when entering the treatment zone to available sulfide in the anaerobic aqueous solution when entering the treatment zone is less than approximately 2.0.

26. The method of claim 1, wherein:

the one or more selected nitrates and/or nitrites comprises nitrous oxide.

27. The method of claim 1, wherein:

the nitrate concentration is maintained for at least 3 minutes.

28. The method of claim 1, wherein:

nitrate concentration is maintained from approximately 3 minutes to approximately 24 hours.

29. The method of claim 1, wherein:

a concentration of the one or more selected nitrates and/or nitrites, when within the treatment zone, is sufficient to reduce available sulfide in the anaerobic aqueous solution.

30. The method of claim 1, wherein:

a concentration of the one or more selected nitrates and/or nitrites, when within the treatment zone, is sufficient to biologically destroy at least a portion of available sulfide in the anaerobic aqueous solution.

31. A method comprising:

in a treatment zone of a manmade container, reacting one or more selected ferric/ferrous chelates, an anaerobic aqueous solution, and an oxygen-comprising gas and/or one or more selected nitrates and/or nitrites,

wherein;

a mass-to-mass ratio of oxygen in the oxygen-comprising gas when entering the treatment zone to available sulfide in the anaerobic aqueous solution when entering the treatment zone is at least approximately 1.5 and less than approximately 3.0; and

a concentration of the one or more selected nitrates and/or nitrites, when within the treatment zone, and a concentration of the one or more selected ferric/ferrous chelates when entering the treatment zone, are sufficient to reduce available sulfide in the anaerobic aqueous solution.