Compositions and methods for the removal of phosphates and other contaminants from aqueous solutions

1. A method of producing a composition capable of removing phosphates, nitrates and heavy metals from a solution, comprising:

(a) forming a slurry from calcium oxide, silicon dioxide, and liquid alkali, wherein the molar ratio of the calcium oxide:silicon dioxide:liquid alkali ranges from 2.43-2.97:1.12-1.38:0.9-1.1

(b) subjecting the slurry to a hydrothermal process from about 1 to 6 hours under about 13.5-16.5 psi of pressure, forming a hydrothermal residue thereby; and

(c) producing the composition capable of removing phosphates, nitrates and heavy metals from a solution by heating the hydrothermal residue at about 540-660° C. for at least about 27 minutes.

2. The method of claim 1 , wherein the liquid alkali is sodium hydroxide.

3. The method of claim 2 , wherein the heating step of claim (c) is performed at 600° C. for 30 minutes.

4. The method of claim 1 , wherein the heating step of claim (c) is performed at 600° C. for 30 minutes.

5. A method of producing a composition capable of removing phosphates, nitrates and heavy metals from a solution, comprising:

(a) forming a slurry from calcium oxide, silicon dioxide, liquid alkali and a metal halide salt, wherein the molar ratio of the calcium oxide:silicon dioxide:liquid alkali:metal halide salt ranges from 48.6-59.4:22.5-27.5:18-22:4.95-6.05

(b) subjecting the slurry to a hydrothermal process from about 1 to 6 hours under about 13.5-16.5 psi of pressure, forming a hydrothermal residue thereby; and

(c) producing the composition capable of removing phosphates, nitrates and heavy metals from a solution by heating the hydrothermal residue at about 540-660° C. for at least about 27 minutes.

6. The method of claim 5 , wherein the liquid alkali is sodium hydroxide.

7. The method of claim 6 , wherein the metal halide salt is ferric chloride hexahydrate.

8. The method of claim 7 , wherein the heating step of claim (c) is performed at 600° C. for 30 minutes.

9. The method of claim 6 , wherein the heating step of claim (c) is performed at 600° C. for 30 minutes.

10. The method of claim 5 , wherein the metal halide salt is ferric chloride hexahydrate.

11. The method of claim 10 , wherein the heating step of claim (c) is performed at 600° C. for 30 minutes.

12. The method of claim 5 , wherein the heating step of claim (c) is performed at 600° C. for 30 minutes.

13. A composition capable of removing phosphates, nitrates and heavy metals from a solution produced by:

(a) forming a slurry from calcium oxide, silicon dioxide, liquid alkali and a metal halide salt, wherein the molar ratio of the calcium oxide:silicon dioxide:liquid alkali:metal halide salt ranges from 48.6-59.4:22.5-27.5:18-22:4.95-6.05

(b) subjecting the slurry to a hydrothermal process from about 1 to 6 hours under about 13.5-16.5 psi of pressure, forming a hydrothermal residue thereby; and

(c) heating the hydrothermal residue at about 540-660° C. for at least about 27 minutes.

14. The composition of claim 13 , wherein the liquid alkali is sodium hydroxide.

15. The composition of claim 14 , wherein the metal halide salt is ferric chloride hexahydrate.

16. The composition of claim 15 , wherein the heating step of claim (c) is performed at 600° C. for 30 minutes.

17. The composition of claim 14 , wherein the heating step of claim (c) is performed at 600° C. for 30 minutes.

18. The composition of claim 13 , wherein the metal halide salt is ferric chloride hexahydrate.

19. The composition of claim 18 , wherein the heating step of claim (c) is performed at 600° C. for 30 minutes.

20. The composition of claim 13 , wherein the heating step of claim (c) is performed at 600° C. for 30 minutes.