Process for modifying the metal ion sorption capacity of a medium

• US 6,436,294 B2
• Filed: 11/24/1998
• Issued: 08/20/2002
• Est. Priority Date: 11/24/1998
• Status: Expired due to Fees

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Lundquist, Susan H.
• Primary Examiner(s): CINTINS, IVARS C
• Application Number:
  US09/199,296
• Publication Number:
  US 20020011446A1
• Time in Patent Office: 1,365 Days
• Field of Search: 210/670, 210/674, 210/682, 210/688, 210/679, 521/26, 502/408
• US Class Current: 210/674
• CPC Class Codes: B01J 20/0211 Compounds of Ti, Zr, Hf
• CPC Class Codes: B01J 20/10 comprising silica or silicate
• CPC Class Codes: B01J 20/28026 Particles within, immobilised, dispersed, entrapped in or on a matrix, e.g. a resin
• CPC Class Codes: B01J 20/2803 Sorbents comprising a binder, e.g. for forming aggregated, agglomerated or granulated products
• CPC Class Codes: B01J 20/28033 Membrane, sheet, cloth, pad, lamellar or mat
• CPC Class Codes: B01J 20/286 Phases chemically bonded to a substrate, e.g. to silica or to polymers
• CPC Class Codes: B01J 20/3007 Moulding, shaping or extruding
• CPC Class Codes: B01J 20/3035 Compressing
• CPC Class Codes: B01J 20/3042 Use of binding agents; addition of materials ameliorating the mechanical properties of the produced sorbent
• CPC Class Codes: B01J 20/3078 Thermal treatment, e.g. calcining or pyrolizing
• CPC Class Codes: B01J 20/3204 Inorganic carriers, supports or substrates
• CPC Class Codes: B01J 20/3248 the functional group or the linking, spacer or anchoring group as a whole comprising at least one type of heteroatom selected from a nitrogen, oxygen or sulfur, these atoms not being part of the carrier as such
• CPC Class Codes: B01J 20/3265 with an organic functional group containing a metal, e.g. a metal affinity ligand
• CPC Class Codes: B01J 20/3295 Coatings made of particles, nanoparticles, fibers, nanofibers
• CPC Class Codes: B01J 2220/52 Sorbents specially adapted for preparative chromatography
• CPC Class Codes: B01J 2220/54 Sorbents specially adapted for analytical or investigative chromatography
• CPC Class Codes: B01J 2220/58 Use in a single column
• CPC Class Codes: B01J 2220/62 In a cartridge
• CPC Class Codes: 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
• CPC Class Codes: B01J 49/50 characterised by the regeneration reagents
• CPC Class Codes: C02F 1/28 : by sorption using ion-exchange C02F1/42; sorbent compositions B01J
• CPC Class Codes: C02F 1/281 : using inorganic sorbents
• CPC Class Codes: C02F 1/285 : using synthetic organic sorbents
• CPC Class Codes: C02F 1/683 : by addition of complex-forming compounds
• CPC Class Codes: C02F 2101/006 : Radioactive compounds
• CPC Class Codes: C02F 2101/20 : Heavy metals or heavy metal compounds

Abstract

A process for modifying a medium is disclosed that includes treating a medium having a metal ion sorption capacity with a solution that includes: A) an agent capable of forming a complex with metal ions; and B) ions selected from the group consisting of sodium ions, potassium ions, magnesium ions, and combinations thereof, to create a medium having an increased capacity to sorb metal ions relative to the untreated medium.

Claims

1. A process for modifying a medium comprising:

preconditioning a medium by treating a medium including a membrane comprising particles, and having a metal ion sorption capacity, with a buffer solution having a pH in the range of 6 to 10 comprising

(a) an agent capable of forming a complex with metal ions, and

(b) ions selected from the group consisting of sodium ions, potassium ions, magnesium ions, and a combination thereof,

said particles in said medium being selected from the group consisting of sodium titanate, crystalline silico titante, mixed salts of titanium silicate, sulfonated styrene divinyl benzene, SAMMS, and a combination thereof, to create a preconditioned medium having an increase capacity to sorb metal ions relative to said untreated medium.

2. The process of claim 1, wherein said agent comprises an organic acid and said ions are sodium ions.

3. The process of claim 1, wherein said agent is citric acid and ions are sodium ions.

4. The process of claim 1, wherein said solution comprises sodium azide.

5. The process of claim 1, wherein said solution comprises an organic acid and sodium hydroxide.

6. The process of claim 1, wherein said solution has a pH of between about 7.5 and 8.5.

7. The process of claim 1, wherein said medium is capable of sorbing strontium ions.

8. The process of claim 1, wherein said medium is capable of sorbing mercury ions.

9. The process of claim 1, wherein said medium comprises sorbed metal ions.

10. The process of claim 1, further comprising contacting said treated medium with a liquid comprising metal ions such that said metal ions sorb onto said medium.

11. The process of claim 10, further comprising treating said medium comprising sorbed metal ions with an agent capable of forming a complex with metal ions for a period sufficient to elute said metal ions.

12. The process of claim 11, wherein said the agent capable of forming a complex with metal ions comprises a solution comprising citric acid and sodium hydroxide.

13. The process of claim 10, further comprising treating said medium comprising sorbed metal ions with a solution comprising an organic acid and sodium hydroxide for a period sufficient to elute said metal ions.

14. The process of claim 10, wherein a back pressure produced during said process remains relatively constant during said process.

15. The process of claim 1 further comprising providing a medium comprising sorbed metal ions, prior to treating said medium.

16. A process for modifying a medium comprising:

treating a medium having enmeshed therein silicotitanate particles and having a metal ion sorption capacity with a solution comprising

(a) citric acid, and

(b) sodium ions,

to create a medium having an increased capacity to sorb metal ions relative to said untreated medium.