Method and apparatus for treating wastewater containing emulsified oil

• US 20070062881A1
• Filed: 09/21/2006
• Published: 03/22/2007
• Est. Priority Date: 09/22/2005
• Status: Active Grant

• Current Assignee: Deren Hu
• Original Assignee: Deren Hu
• Inventors: Hu, Deren
• Granted Patent: US 8,273,240 B2
• Time in Patent Office: Days
• US Class Current: 210/748.170
• CPC Class Codes: C02F 1/40 Devices for separating or removing fatty or oily substances or similar floating material cleaning or keeping clear the surface of open water from oil or like materials E02B15/04; devices in sewers for separating liquid or solid substances from sewage E03F5/14, e.g. for use in drains leading to the sewer E03F5/16
• CPC Class Codes: C02F 1/46114 Electrodes in particulate form or with conductive and/or non conductive particles between them
• CPC Class Codes: C02F 1/4674 with halogen or compound of halogens, e.g. chlorine, bromine
• CPC Class Codes: C02F 2001/46138 Electrodes comprising a substrate and a coating
• CPC Class Codes: C02F 2101/325 Emulsions
• CPC Class Codes: C02F 2103/16 from metallurgical processes, i.e. from the production, refining or treatment of metals, e.g. galvanic wastes
• CPC Class Codes: C02F 2305/023 Reactive oxygen species, singlet oxygen, OH radical

Abstract

In one embodiment of the present invention, a method for treating wastewater that contains emulsified oil is provided. The method comprises feeding the wastewater that contains the emulsified oil to an electrolytic tank, and oxidatively electrolyzing the wastewater that contains the emulsified oil using indissoluble electrodes. The negatively charged emulsified oil particles in the wastewater are neutralized on a surface of an anode during the oxidative electrolysis. The anode comprises an indissoluble electrode with oxygen radical-generating characteristics. The method further comprises particle group electrolyzing the wastewater using particle groups, and discharging the treated wastewater.

Claims

1. A method for treating wastewater that contains emulsified oil, the method comprising:

feeding the wastewater that contains the emulsified oil to an electrolytic tank;

oxidatively electrolyzing the wastewater that contains the emulsified oil using indissoluble electrodes, wherein negatively charged emulsified oil particles in the wastewater are neutralized on a surface of an anode during the oxidative electrolysis, the anode comprising an indissoluble electrode with oxygen radical-generating characteristics;

particle group electrolyzing the wastewater using particle groups; and

discharging the treated wastewater.

2. The method of claim 1, wherein subsequent de-emulsification of the negatively charged emulsified oil particles produces oil aggregates that float upwardly to an upper part of the electrolytic tank.

3. The method of claim 1, wherein the anode both neutralizes the negative charges on the emulsified oil particles and produces hydroxyl radicals during the oxidative electrolysis, the hydroxyl radicals reacting with the emulsified oil particles such that de-emulsification of the emulsified oil particles is accelerated and substantially no solid sediments are produced during the oxidative electrolysis.

4. The method of claim 1, wherein a voltaic concentration for the oxidative electrolysis using indissoluble electrodes is about 1.4˜

1.6 Ah/L and an electrolytic time thereof is about 8˜

15 minutes.

5. The method of claim 1, wherein an electrolytic current for the particle group electrolysis is about 5˜

10 A, a voltage thereof is about 30˜

50 V, and an electrolytic time thereof is about 6˜

8 minutes.

6. The method of claim 1, wherein each of the indissoluble electrodes comprises a metal base coated with an oxide, and wherein the indissoluble electrodes transmit an output electric current in the electrolysis process and are not subject to any substantial electrolytic consumption.

7. The method of claim 6, wherein the metal base comprises titanium.

8. The method of claim 6, wherein the oxide comprises one of titanium dioxide, tin oxide, iridium dioxide or the combination thereof.

9. The method of claim 1, wherein the particle groups comprise active carbon particles and insulating plastic particles.

10. The method of claim 9, wherein the active carbon particles and the insulating plastic particles are mixed such that the active carbon particles are separated by the insulating plastic particles, and wherein the active carbon particles, which are electrically conductive, are polarized by an electric field generated during electrolysis and each active carbon particle becomes a primary cell, which together form a plurality of primary cell electrolytic units when an electric current is applied, and on the surfaces of which the emulsified oil particles in the wastewater adsorb and are electrolyzed.

11. The method of claim 1, further comprising separating non-emulsified oil in the wastewater from the wastewater containing emulsified oil by a conventional separation process before the oxidatively electrolyzing the wastewater.

12. The method of claim 11, wherein the conventional separation process comprises a process using gravitational and filtration-adsorption separation.

13. A system for treating wastewater that contains emulsified oil, the system comprising:

a feed tank;

an oxidative electrolysis chamber in fluid communication with the feed tank that includes indissoluble electrodes, wherein one of the indissoluble electrode is an anode with oxygen radical-generating characteristics;

a particle group electrolysis chamber in fluid communication with the oxidative electrolysis chamber that includes a plurality of particle groups; and

a discharge pipe that connects to the particle group electrolysis chamber.

14. The system of claim 13, wherein each of the indissoluble electrodes comprises a metal base coated with an oxide, and wherein the indissoluble electrodes transmit an output electric current in the electrolysis process and are not subject to any substantial electrolytic consumption.

15. The system of claim 13, wherein the metal base comprises titanium.

16. The system of claim 13, wherein the oxide comprises one of titanium dioxide, tin oxide, iridium dioxide or the combination thereof.

17. The system of claim 13, wherein the particle groups comprise active carbon particles and insulating plastic particles.

18. The system of claim 13, wherein the active carbon particles and the insulating plastic particles are mixed such that the active carbon particles are separated by the insulating plastic particles, wherein the active carbon particles, which are electrically conductive, are polarized by an electric field generated during electrolysis and each active carbon particle becomes a primary cell, which together form a plurality of primary cell electrolytic units when an electric current is applied, and on the surfaces of which the emulsified oil particles in the wastewater adsorb and are electrolyzed.

19. The system of claim 13, further comprising a gravitational and filtration-adsorption separator.

20. A system for treating wastewater that contains emulsified oil comprising:

a feed means;

an oxidative electrolysis meansr in fluid communication with the feed means that includes indissoluble electrodes, wherein one of the indissoluble electrode is an anode with oxygen radical-generating characteristics;

a particle group electrolysis means in fluid communication with the oxidative electrolysis means that includes a plurality of particle groups; and

a discharge means that connects to the particle group electrolysis means.