Method for purifying food and meat processing facility liquids and process or waste waters by using a combination of metal salts and a flocculant to coagulate and then flocculate contaminants from a contaminated liquid

Abstract

A method for purifying contaminated liquids, especially waste water with high TKN/BOD concentrations, by first introducing, into the contaminated liquid, an acidic coagulant such as a metal salt and then introducing a second alkaline coagulant, into the contaminated liquid which dramatically increases the speed and effectiveness of subsequent coagulation and flocculation and thereby removal of TKN/BOD. By comparing the total (molar amount of acidic coagulant cation+alkaline coagulant cation) with an equal molar amount of the acidic cation, superior removal of TKN/BOD are achieved due to a synergy between the acidic and alkaline coagulant versus using just an acidic metal coagulant.

Claims

1. A method for purifying a contaminated liquid, the method comprising promoting coagulation of the contaminants of the contaminated liquid by first adding to a contaminated liquid an acidic metal salt and second adding to a contaminated liquid an alkaline metal salt.

2. The method of purifying a contaminated liquid of claim 1, with the contaminated liquid being water.

3. The method of purifying a contaminated liquid of claim 2, further comprising a step of adjusting the pH of the contaminated liquid by adding an acid or a base before the addition of a metal salt to the contaminated liquid.

4. The method of purifying a contaminated liquid of claim 3, further comprising a step, following the addition of an alkaline metal salt to the contaminated liquid, to add a flocculant to the contaminated liquid.

5. The method of purifying a contaminated liquid of claim 4, further comprising a step, following the addition of a flocculant to the contaminated liquid, in which the contaminated liquid remains in a holding tank and the flocculated contaminants separate from the contaminated liquid in the holding tank.

6. The method of purifying a contaminated liquid of claim 5, further comprising a step, following the flocculated contaminants separating from the contaminated liquid in the holding tank of removing the contaminated liquid from the holding tank.

7. A method for purifying a contaminated liquid, the method comprising the steps of adding both an acidic metal salt and an alkaline metal salt to the contaminated liquid; adding a flocculant to the contaminated liquid; allowing the contaminated liquid to remain in a holding tank; allowing the contaminants in the contaminated liquid to floc and separate from the contaminated liquid in the holding tank; and removing the contaminated liquid from the holding tank.

8. The method of purifying a contaminated liquid of claim 7, with the contaminated liquid being water.

9. The method of purifying a contaminated liquid of claim 8, with the acidic metal salt being a bi, tri or quad valent acidic metal salt.

10. The method of purifying a contaminated liquid of claim 8, with the alkaline metal salt being sodium aluminate.

11. The method of purifying a contaminated liquid of claim 9, with the acidic metal salt comprising a salt of zirconium, aluminum, or iron,

11. The method of purifying a contaminated liquid of claim 11, further comprising with the acidic metal salt comprising zirconium oxychloride, aluminum sulfate, aluminum chloride, poly aluminumchloride, aluminumhydroxychloride, ferric chloride, ferric sulfate, ferrous chloride, or ferrous sulfate.

12. A method of purifying a contaminated liquid by coagulation and flocculation, the method comprising the steps of: Pre-conditioning the contaminated liquid by adjusting the pH of the contaminated liquid; introducing an acidic metal salt into the contaminated liquid; introducing a basic metal salt into the contaminated liquid; introducing a flocculant into the contaminated liquid.

13. The method of claim 12, in which the contaminated liquid is water.

14. The method of claim 13, in which the metal salt is a bi, tri or quad valent acidic metal salt.

15. The method of claim 14, in which the acidic metal salt is introduced into the contaminated liquid to a concentration of 50 to 5000 parts per million.

16. The method of claim 15, in which the basic metal salt is introduced into the contaminated liquid to a concentration of 50 to 5000 parts per million.

17. The method of claim 16, in which the flocculant is introduced into the contaminated liquid to a concentration of 10 to 500 parts per million.

18. The method of claim 17, in which, after the introduction of the flocculant, the contaminated liquid is retained in a holding tank allowing the contaminants to flocculate and separate from the contaminated liquid in a holding tank.

19. The method of claim 18, in which, the contaminated liquid is removed from the holding tank after the flocculated contaminants have separated in the holding tank.

20. The method of claim 19, in which, the pH of the contaminated liquid is preconditioned by adjusting the pH of the contaminated liquid to a value of between 5.5 and 8.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0024] While drawings are not required for a method patent such as this one:

[0025] FIG. 1 shows a flow chart of one embodiment of the invention described in the claims.

[0026] FIG. 2 shows a flow chart of one embodiment of the invention described in the claims.

[0027] FIG. 3 shows a flow chart of one embodiment of the invention described in the claims.