Organic containing sludge to fertilizer alkaline conversion process
This invention is directed to systems, devices and methods for treating organic-containing sludges and converting such sludges to high value fertilizers containing both inorganic and organic fertilizer components, which creates an inorganically-augmented bioorganic fertilizer. The invention describes methods to create a thixotropic or paste-like material via the application of mixing energy to the organic sludge followed by an alkaline treatment and a subsequent ammoniation. The invention further describes a method to increase the plant nutrient content in the organic containing product to a level which permits the finished granular fertilizer product to compete in the commercial agricultural fertilizer marketplace. Further, the invention reduces odors associated with said organic-containing sludges.
1. A method of fertilizer manufacture comprising:
creating a thixotropic paste from a composition containing biosolids;
adding an alkaline agent to the paste to produce a pH of 10 or higher;
exposing the paste to ammonia at a concentration of at least 1,000 ppm
adding an acid to the paste to produce heat and a pH 7.0 or less;
drying the paste to a dryness of 90% or more of solids.
2. The method of claim 1 , wherein the biosolids are selected from the group consisting of municipal biosolids and sludges, manures and animal residuals, lagoon sludges, organic-containing sludges produced from food fermentation, sludge waste products, pharmaceutical fermentation waste industrial fermentation products, and mixture and combinations thereof.
3. The method of claim 1 , further comprising adding as an oxidizing agent hypochlorite, sodium hypochlorite, calcium hypochlorite, iron oxide, metal oxide, calcium ferrate, potassium ferrate, sodium ferrate, oxygen, hydrogen peroxide, peroxide, ozone, chlorine dioxide, or a combination thereof.
4. The method of claim 1 , wherein the alkaline agent is selected from the group consisting of calcium oxide, calcium hydroxide, potassium hydroxide, sodium hydroxide, alkaline by products, cement kiln dust, lime kiln dust, Class C fly ash, Class F fly ash, lime-injected fly ash, high-alkaline materials, and combinations thereof.
5. The method of claim 1 , wherein, after addition of the alkaline agent, the mixture is pH 11 or higher.
6. The method of claim 1 , wherein the ammonia is aqueous or anhydrous ammonia.
7. The method of claim 1 , wherein the concentration of ammonia is at least 5,000 ppm.
8. The method of claim 1 , wherein the concentration of ammonia is at least 10,000 ppm.
9. The method of claim 1 , wherein the concentration of ammonia is at least 20,000 ppm.
10. The method of claim 1 , wherein the exposure is for at least 30 seconds.
11. The method of claim 1 , wherein the exposure is for at least 2 minutes.
12. The method of claim 1 , wherein the exposure is for at least 5 minutes.
13. The method of claim 1 , wherein the concentration of ammonia provides a dry weight nitrogen concentration of 6%.
14. The method of claim 1 , wherein the concentration of ammonia provides a dry weight nitrogen concentration of 10%.
15. The method of claim 1 , wherein the concentration of ammonia provides a dry weight nitrogen concentration of 14%.
16. The method of claim 1 , wherein, after addition of the alkaline agent, the mixture is pH 11 or higher.
17. The method of claim 1 , wherein the acid is phosphoric or sulfuric acid.
18. The method of claim 1 , wherein the concentrated acid is selected from the group consisting of phosphoric acid, sulfuric acid, sulfamic acid, hydrochloric acid, nitric acid and combinations thereof.
19. The method of claim 1 , wherein, after treating with the acid, the paste is pH 7.0 or less.
20. The method of claim 1 , further comprising blending a plant nutrient with the thixotropic paste to increase nitrogen, phosphorus and iron levels.
21. The method of claim 20 , wherein the plant nutrient content is at least 8% nitrogen by dry weight.
22. The method of claim 20 , wherein the plant nutrient content is at least 12% by dry weight.
23. The method of claim 20 , wherein the plant nutrient content is at least 15% by dry weight.
24. The method of claim 1 , wherein odor associated with the paste is reduced.
25. The method of claim 1 , wherein the thixotropic paste is treated with an oxidizing agent such that odorants emission is reduced simultaneously with increasing plant nutrient concentration.
26. The method of claim 1 , wherein the extruded paste is formed into pellets or granules.
27. The method of claim 26 , wherein the pellets or granules are coated.
28. The method of claim 1 , further comprising storing the dried paste in a dry environment.
29. The method of claim 1 , further comprising applying the dried paste to plants as a fertilizer.
30. The method of claim 1 , further comprising applying an antimicrobial stress during any step.
31. The method of claim 30 , wherein the microbial stress is selected from the group consisting of a pH greater than pH 10, a pH greater than pH 11.0; free ammonia concentration in the paste at greater than 1,000 ppm, free ammonia concentration in the paste at greater than 10,000 ppm; free ammonia concentration in the paste at greater than 15,000 ppm; heat at greater than 80° C.; greater than 100° C., heat at greater than 121° C. and combinations thereof.
32. The method of claim 1 , further comprising adding a fertilizer to the dried pellets or granules to provide nutrient enhancement.
33. The method of claim 32 , wherein the fertilizer is selected from the group consisting of dry fertilizers, liquid fertilizers, ammonium sulfate, ammonium nitrate, mono-ammonium phosphate, di-ammonium phosphate, urea, urea ammonium nitrate (“UAN”), liquid urea, liquid N-P-K fertilizers, 16-4-8, 10-8-8, 6-14-6, and combinations thereof.