초록

A method for removing and recovering phosphorus from a spent adsorbent medium to result in a regenerated medium and a phosphorus-containing solution useful as a fertilizer.

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What is claimed is: 1. A method for recovering phosphorus desorbed from an influent solution to an adsorptive medium, resulting in a spent medium, the method comprising contacting the phosphorus containing spent medium with a solution of potassium hydroxide to form a first effluent; and contacting

What is claimed is: 1. A method for recovering phosphorus desorbed from an influent solution to an adsorptive medium, resulting in a spent medium, the method comprising contacting the phosphorus containing spent medium with a solution of potassium hydroxide to form a first effluent; and contacting the first effluent with a solution of nitric acid to form a second effluent, the second effluent containing phosphorus, potassium, and nitrogen. 2. The method of claim 1 wherein the spent sorbent is a metal oxide adsorbent, an ion-exchange adsorbent, or a hybrid adsorbent. 3. The method of claim 1 wherein said phosphorus comprises a phosphate. 4. The method of claim 1 wherein said phosphorus comprises at least one member selected from the group consisting of an orthophosphate anion, a polyphosphate anion, an acid of an orthophosphate anion, and an acid of a polyphosphate anion. 5. The method of claim 1 wherein the second effluent includes potassium, nitrate, and phosphate ions. 6. The method of claim 5 further comprising the step of separating the potassium nitrate and the potassium phosphate from the second effluent. 7. The method of claim 1 wherein the medium comprises a plurality of beads. 8. The method of claim 1 further comprising the step of applying the second effluent as a fertilizer. 9. The method of claim 1 wherein the ratio of nitrogen:phosphorus:potassium in the second effluent is adjusted. 10. The method of claim 1 wherein the second effluent is adjusted to increase the concentration of at least one member selected from the group consisting of nitrogen, phosphorus, and potassium. 11. The method of claim 1 wherein the concentration of potassium hydroxide ranges from about 0.1% to about 10%. 12. The method of claim 1 wherein the concentration of nitric acid ranges from about 1% to about 70%.