Nitrogen extraction from organic wastes for fertigation in organic agriculture
View Patent ↗A method is provided for manufacturing a liquid nitrogen fertilizer from organic wastes and manures, in which nitrogen is extracted as an aqueous ammonia, and further concentrated, and eventually converted to nitrate in a biological reactor. The method may utilize nitrogen rich organic wastes and manures, such as wastewater sludge, slaughter house wastes, broiler layer, and guano, and it is especially suitable for providing a nitrogen fertilizer in organic farming.
1. A method of manufacturing a liquid nitrogen fertilizer from a fowl manure organic waste, comprising the steps of
extracting the waste in water under aerated conditions, wherein an aqueous solution is obtained containing nitrogen essentially in form of ammonia;
volatilizing said ammonia; and
absorbing the volatilized ammonia in either (1) a liquid medium, or (2) a solid medium, and further extracting said solid medium in water or water based liquid.
2. A method according to claim 1 , further comprising converting at least a part of the absorbed ammonia to nitrate using nitrifying bacteria.
3. A method according to claim 1 , wherein said step of volatilizing further comprises adding a base or increasing the temperature.
4. A method according to claim 1 , wherein said volatilizing occurs at least partially spontaneously.
5. A method according to claim 1 , wherein said medium is selected from the group consisting of an aqueous solution, a bio-solid substance, and a sorbent.
6. A method according to claim 5 , wherein said bio-solid substance comprises compost or a manure.
7. A method according to claim 5 , wherein said sorbent is selected from the group consisting of plastic beads, vermiculite, and zeolite.
8. A method according to claim 2 , wherein said bacteria are suspended in a liquid or bound onto a solid surface.
9. A method according to claim 1 , wherein said volatilizing occurs either consequently to said step of extracting or simultaneously with said step of extracting.
10. A method according to claim 2 , further comprising extracting said nitrate in water, thereby obtaining said liquid nitrogen fertilizer.
11. A method according to claim 1 , wherein said liquid medium is used as said liquid nitrogen fertilizer.
12. A method according to claim 1 , wherein said fertilizer has higher concentration of available nitrogen than said aqueous solution obtained by said extracting.
13. A method according to claim 1 , wherein at least 25% of nitrogen initially present in the waste is extracted and obtained as available nitrogen.
14. A method according to claim 13 , wherein said nitrogen is available as ammonia or nitrate.
15. A method according to claim 1 , wherein said manure is selected from the group consisting of Broiler manure, Layer manure, and Guano.
16. A method according to claim 1 , wherein said extraction comprises brewing performed for about four days or more.
17. A method of manufacturing a liquid nitrogen fertilizer for organic agriculture, comprising the steps of
extracting a fowl manure organic waste in water under aerated conditions, wherein a first aqueous solution is obtained containing nitrogen essentially in the form of ammonia;
volatilizing said ammonia, the volatilization being assisted by increased temperature or by increased pH;
absorbing the volatilized ammonia in either (1) a second aqueous solution or (2) a solid matrix, and further extracting said solid matrix in water, and optionally
converting at least a part of ammonia to nitrate, using nitrifying bacteria.
18. A method according to claim 17 , wherein said step of extracting is performed in a first reactor, and said step of converting the ammonia to nitrate is performed in a second reactor.
19. A method according to claim 18 , wherein said step of absorbing the volatilized ammonia is performed in said second reactor.
20. A method according to claim 18 , wherein said second reactor comprises nitrifying bacteria bound in a bio-solid substance or in a sorbent.