# US 9,006,299 B2 · Method for removal of metal ions from an aqueous solution

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- Number: US 9,006,299 B2
- Document ID: US9006299B2
- Status: Granted
- Kind: B2
- Application number: 13/521,507
- Filed: 2011-07-12
- Published: 2014-05-29
- Granted: 2015-04-14
- Earliest claimed: 2011-07-12
- Assignees: King Saud University
- Applicants: Saad M. Alshehri; Tansir Ahamad
- Inventors: Saad M. Alshehri; Tansir Ahamad
- Web page: https://patentgrep.com/patent/US9006299B2

## CPC

- B01J 39/19: obtained otherwise than by reactions only involving unsaturated carbon-to-carbon bonds
- B01J 39/04: Processes using organic exchangers
- B01J 41/04: Processes using organic exchangers
- B01J 41/13: obtained otherwise than by reactions only involving unsaturated carbon-to-carbon bonds
- B01J 45/00: Ion-exchange in which a complex or a chelate is formed; Use of material as complex or chelate forming ion-exchangers; Treatment of material for improving the complex or chelate forming ion-exchange properties (ion-exchange chromatography processes B01D15/36)
- C02F 1/42: by ion-exchange (ion-exchange in general B01J)
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- C02F: TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE (separation in general B01D; special arrangements on waterborne vessels of installations for treating water, waste water or sewage, e.g. for producing fresh water, B63J; adding materials to water to prevent corrosion C23F; treating radioactively-contaminated liquids G21F9/04; regeneration of reactants for recirculation into processes, see the relevant places for the processes)

## Abstract

The present invention relates to a method for removal of metal ions from an aqueous solution, which comprises contacting the aqueous solution with a phosphazene-formaldehyde resin as well as an ion exchange resin comprising a phosphazene-formaldehyde resin.

## Claims

### Claim 1

Method for removal of metal ions from an aqueous solution, which comprises:
reacting hexaminocyclotriphosphazene hexammoniumchloride ({NP(NH2)2}3.6NH4Cl) and formaldehyde (HCHO) in an aqueous environment to form a phosphazene-formaldehyde resin; and
contacting the aqueous solution with the phosphazene-formaldehyde resin.

### Claim 2 (depends on 1)

Method according to claim 1, wherein the metal ions are selected from the group consisting of heavy metal ions.

### Claim 3 (depends on 1)

Method according to claim 1, wherein the pH of the aqueous solution is from 6 to 8, wherein the aqueous solution optionally contains a respective buffer.

### Claim 4 (depends on 1)

Method according to claim 1, wherein the aqueous solution is ground water, sea water, or waste water.

### Claim 5 (depends on 1)

Method according to claim 1, wherein the phosphazene-formaldehyde resin is separated from the aqueous solution after contacting therewith.

### Claim 6 (depends on 5)

Method according to claim 5, wherein the metal ions are removed from the separated phosphazene-formaldehyde resin.

### Claim 7 (depends on 6)

Method according to claim 6, wherein the phosphazene-formaldehyde resin removed from the metal ions is recycled and/or re-used.

### Claim 8 (depends on 1)

Method according to claim 1, wherein the metal of said metal ions are is selected from the group consisting of lead and transition metals.

### Claim 9 (depends on 1)

Method according to claim 1, wherein the metal of said metal ions is selected from the group consisting of cadmium, copper, zinc and nickel.