Method and system for treating waste matter from animals, urea-rich and urea-lean waste-matter products, and uses thereof

1. A method of treating waste matter from animals, the method comprising:

a) collecting waste matter from the animals;

b) inhibiting urease activity in said collected waste matter; and

c) separating said urease-activity inhibited waste matter into a urea-rich fraction essentially consisting of a liquid comprising urea and other components soluble in liquid manure and a urea-lean fraction;

d) irreversibly inhibiting urease activity in said urea-rich fraction wherein said irreversible inhibition comprises treating said urea-rich fraction with an irreversible inhibitor, said inhibitor being selected among the group consisting of

urea compounds selected from the group consisting of hydroxyurea, selenourea, phenylurea and thiourea;

benzoeates selected from the group consisting of p-substituted mercuribenzoate, p-chloromercuribenzoate, p-hydroxymercuribenzoate and iodosobenzoate;

p-chloromercuribenzenesulfonate;

N-ethylmaleimide;

phosphor compounds selected from the group consisting of phosphoramidate and phosphate;

monovalent ions selected from the group consisting of F − , Na + , and K + ;

divalent metal ions selected from the group consisting of Hg 2+ , Cu 2+ , Fe 2+ , Co 2+ , Zn 2+ , Ni 2+ , Mn 2+ , Cd 2+ , Ag + , Mg 2+ (weak), Ba 2+ , Pb 2+ ,

and combinations thereof in form of at least one water-soluble salt, and/or at least one electrochemically-released ion;

As 3+ ;

at least one nickel-complexing agent selected from the group consisting of dimethylglyoxime, ethylenediamine and combinations thereof, and

compounds selected from the group consisting of beta-mercaptoethanol, iodine, suramin, phenylsulfinate, and furacin;

e) recovering the urea-rich essentially liquid fraction obtained in step c); and

f) recovering the urea-lean fraction obtained in step c;

wherein said inhibition of step b) comprises treating said collected waste matter by a method including at least one step selected from the group consisting of decreasing pH, buffering pH, at least one of decreasing and increasing pressure, at least one of decreasing and increasing ionic strength and combinations thereof.

2. The method according to claim 1 , wherein said urea-lean fraction is in form of a liquid, a solid, or a combination thereof, or in form of a dried solid.

3. The method according to claim 1 , wherein said irreversible inhibitor is recovered from said irreversibly urease-activity inhibited and separated urea-rich fraction.

4. The method according to claim 1 , wherein said waste-matter comprises feces and liquid manure from farm animals.

5. The method according to claim 1 , wherein the irreversible inhibitor is at least one divalent metal ion and the divalent metal ions are selected from the group consisting of Cu 2+ , Ag + and Pb2+.

6. A method of producing thermosetting urea-formaldehyde plastic from waste matter of animals, the method comprising:

a) producing an essentially liquid urea-rich fraction of the waste matter from the animals by a method comprising:

i) collecting waste matter from the animals;

ii) inhibiting urease activity in said collected waste matter;

iii) separating said urease-activity inhibited waste matter into a urea-rich fraction essentially consisting of a liquid comprising urea and other components soluble in liquid manure and a urea-lean fraction; said inhibition comprising reversible inhibiting urease activity of said collected waste matter before said separation of said urease-activity inhibited waste matter into said urea-rich fraction and said urea-lean fraction; and

iv) irreversibly inhibiting urease activity in said urea-rich fraction, wherein said irreversible inhibition comprises treating said urea-rich fraction with an irreversible inhibitor, said inhibitor being selected among the group consisting of:

urea compounds selected from the group consisting of hydroxyurea, selenourea, phenylurea and thiourea;

benzoeates selected from the group consisting of p-substituted mercuribenzoate, p-chloromercuribenzoate, p-hydroxymercuribenzoate and iodosobenzoate;

p-chloromercuribenzenesulfonate;

N-ethylmaleimide;

phosphor compounds selected from the group consisting of phosphoramidate and phosphate;

monovalent ions selected from the group consisting of F − , Na + , and K + ;

divalent metal ions selected from the group consisting of Hg 2+ , Cu 2+ , Fe 2+ , Co 2+ , Zn 2+ , Ni 2+ , Mn 2+ , Cd 2+ , Ag + , Mg 2+ (weak), Ba 2+ , Pb +2 and combinations thereof in form of at least one water-soluble salt, and/or at least one electrochemically-released ion;

As 3+ ;

at least one nickel-complexing agent selected from the group consisting of dimethylglyoxime, ethylenediamine and combinations thereof, and

compounds selected from the group consisting of beta-mercaptoethanol, iodine, suramin, phenylsulfinate, and furacin, and

b) reacting said urea-rich fraction with methanal.

7. The method according to claim 6 , wherein said waste matter comprises feces and liquid manure from farm animals.

8. The method according to claim 6 , wherein said irreversible inhibitor comprises divalent metal ions selected from the group consisting of Cu 2+ , Ag 30 and Pb 2+ and combinations thereof.

9. The method according to claim 6 , wherein said separating step comprises centrifugation or filtration.

10. The method according to claim 9 , said method further comprising subjecting said urea-rich fraction to ultra-filtration to produce a urea-rich permeate.

11. The method according to claim 10 , said method further comprising subjecting said urea-rich permeate to nano-filtration to produce a urea-rich nano-filtered permeate.

12. The method according to claim 11 , said method further comprising subjecting said urea-rich nano-filtered permeate to hyper-filtration to produce a urea-rich concentrate.

13. The method according to claim 6 , wherein the urea-rich fraction is reacted with methanal under acidic conditions.

14. The method according to claim 6 further comprising concentrating the urea formaldehyde product.