Device for electrocoagulation and process

Patent metadata

Field	Value
Publication number	US-10392274-B2
Application number	US-201715699307-A
Country	US
Kind code	B2
Filing date	Sep 8, 2017
Priority date	Sep 9, 2016
Publication date	Aug 27, 2019
Grant date	Aug 27, 2019

Abstract

A device for electrocoagulation to treat a process stream, such as water, wastewater, or industrial waste. Also, a method to treat a process stream, such as water or wastewater, or industrial waste, utilizing said device. An electrocoagulation device configured to treat a process stream, the device including a cathode; an anode, wherein the anode is porous and water permeable; and a pressure system, wherein the pressure system is configured to flow at least 95% of the process stream through the anode.

First claim

The invention claimed is:

1. An electrocoagulation device configured to treat a process stream, the device comprising:
a cathode;
a sacrificial anode consisting of a compacted powder comprising iron and having a porosity between 11 and 62% by volume, wherein said anode is porous and water permeable;
a pressure system, wherein the pressure system is configured for the process stream to flow through said anode,
wherein said anode has a first side and an opposite second side, wherein the process stream flows from the first side through said anode to the second side,
wherein a pressure of the process stream on the second side is less than the pressure on the first side, such that a pressure differential is at least 6.9 kPa (1 psi).

2. The device according to claim 1 , wherein the pressure system is configured such that at least 50 wt % of the process stream flows through said anode.

3. The device of claim 1 , wherein the pressure of the process stream on the first side is at least 13.8 kPa (2 psi).

4. The device according to claim 1 , wherein said anode has a porosity between 22-51% by volume.

5. The device according to claim 1 , wherein said anode consists of compacted and sintered powder.

6. The device according to claim 1 , wherein the compacted powder comprises at least 90% by weight of iron.

7. The device according to claim 1 , wherein the compacted powder comprises iron powder having a particle size distribution such that the amount of particles below 45 μm being at most 10% by weight, between 45 and 150 μm being 0-20% by weight, between 150 and 212 μm being 10-50% by weight, between 212 and 500 μm being 50-90% by weight and above 500 μm being 0-30% by weight.

8. The device according to claim 7 , wherein said iron powder has a particle size distribution such that amount of particles below 45 μm being at most 5% by weight, between 45 and 150 μm being 0-20% by weight, between 150 and 212 μm 10-30% by weight, between 212 and 500 μm being 60-90% by weight and above 500 μm being 0-10% by weight.

9. The device according to claim 1 , wherein said compacted powder comprises a mixture of compacted iron powder and aluminum powder.

10. The device according to claim 9 , wherein the weight ratio between iron powder and aluminum powder 50:50 to 98:2.

11. A process for treating a process stream by electrocoagulation containing the following steps:
providing a device according to claim 1 ,
passing the process stream through the device by pressurizing the process stream before passing through said anode, while supplying an electric potential difference between said anode and said cathode.

12. The process according to claim 11 , wherein when said anode and cathode are identical in structure, the process further comprises the step of:
switching polarity when a sacrificial part of said anode at least partly is consumed.

13. The process according to claim 11 , wherein the process stream is pressurized above atmospheric pressure before passing through said anode.

14. The process according to claim 11 , wherein said anode has a saturated hydraulic conductivity (K sat ) value of above 0 and up to 19 cm/day.

15. The process according to claim 11 , wherein the process further comprises, prior to, and/or during the process of passing the process stream through the device, adjusting pH to a value which prohibits dissolution of formed hydroxide flocculants.

16. The method according to claim 11 , wherein the process stream comprises at least one heavy metal.

17. The method according to claim 11 , wherein the process stream comprises fluoride.

18. The method according to claim 11 , wherein the at least one heavy metal is chromium.

19. The method according to claim 11 , wherein the at least one heavy metal is arsenic.

Assignees

• Hoganas Ab Publ
• Hoeganaes Ab Publ

Inventors

• Unger Kyle
• Tandukar Madan
• Endler Paul

Classifications

• C02F2301/06

  Pressure conditions · CPC title

• C02F2101/14

  Fluorine or fluorine-containing compounds · CPC title

• C02F2101/106

  Selenium compounds · CPC title

• C02F2101/103

  Arsenic compounds · CPC title

• C02F1/4678 Primary

  of metals · CPC title