Measurement of ion concentration in presence of organics

• US 9,880,124 B2
• Filed: 11/10/2015
• Issued: 01/30/2018
• Est. Priority Date: 11/10/2014
• Status: Active Grant

• Current Assignee: Calera Corporation
• Original Assignee: Calera Corporation
• Inventors: Gilliam, Ryan J., Zhao, Hong
• Primary Examiner(s): Wallenhorst, Maureen
• Application Number:
  US14/937,751
• Publication Number:
  US 20160131612A1
• Time in Patent Office: 812 Days
• Field of Search: 436 73, 436 77, 436 80, 436 83, 436 84, 436124, 436125, 436139, 436142, 436128, 436132, 436149, 436150, 436151, 436178, 422 8201, 422 8202, 422 69
• CPC Class Codes: G01N 27/38 Cleaning of electrodes
• CPC Class Codes: G01N 27/401 Salt-bridge leaks; Liquid junctions
• CPC Class Codes: G01N 27/49 Systems involving the determination of the current at a single specific value, or small range of values, of applied voltage for producing selective measurement of one or more particular ionic species
• CPC Class Codes: G01N 33/1813 specific cations in water, e.g. heavy metals electrochemical analysis G01N27/26; detection of ions by colorimetry G01N31/22
• CPC Class Codes: Y10T 436/255 including use of a solid sorbent, semipermeable membrane, or liquid extraction

Abstract

Disclosed herein are systems and methods that relate to use of ultramicroelectrodes (UME) in measurement of ion concentration in presence of one or more organic compound(s).

Claims

1. A method to measure concentration of metal ions in presence of one or more organic compounds in an aqueous medium comprising:

contacting an aqueous medium comprising metal ions and one or more organic compounds with an ultramicroelectrode (UME) in a UME cell;

cleaning surface of the UME from deposition of the one or more organic compounds by passing a gas on the surface of UME, by forming a gas on the surface of UME, by mechanically cleaning the surface of UME, or combinations thereof;

subjecting the UME to a set Y of one or more potential cycles causing oxidation of the metal ions in lower oxidation state to a higher oxidation state or causing reduction of the metal ions in higher oxidation state to a lower oxidation state; and

measuring a steady state current in the UME and calculating the concentration of the metal ions.

2. The method of claim 1, wherein the cleaning of the surface of the UME from the deposition of the one or more organic compounds by forming the gas on the surface of UME comprises subjecting the UME to a set X of one or more potential cycles to form oxygen gas, chlorine gas, hydrogen gas, sulfur dioxide gas, or combinations thereof, on the surface of the UME.

3. The method of claim 2, wherein voltage range of the set X of the one or more potential cycles is higher than reduction potential of the metal ion to prevent reduction of the metal ion and its deposition on the UME surface, wherein the metal ion is iron, chromium, copper, tin, silver, cobalt, uranium, lead, mercury, vanadium, bismuth, titanium, ruthenium, osmium, europium, zinc, cadmium, gold, nickel, palladium, platinum, rhodium, iridium, manganese, technetium, rhenium, molybdenum, tungsten, niobium, tantalum, zirconium, hafnium, and combinations thereof.

4. The method of claim 2, wherein voltage range of the set X of the one or more potential cycles is ±

5V vs Standard Hydrogen Electrode (SHE), ±

3V vs SHE, between 0.2V to 2.5V vs SHE, or between 0.6V to 2.5V vs SHE.

5. The method of claim 1, wherein voltage range of the set Y of the one or more potential cycles comprises oxidation or reduction potential of the metal ions or is between open circuit potential of the metal ions and the oxidation or reduction potential of the metal ions, wherein the metal ion is iron, chromium, copper, tin, silver, cobalt, uranium, lead, mercury, vanadium, bismuth, titanium, ruthenium, osmium, europium, zinc, cadmium, gold, nickel, palladium, platinum, rhodium, iridium, manganese, technetium, rhenium, molybdenum, tungsten, niobium, tantalum, zirconium, hafnium, and combinations thereof.

6. The method of claim 5, wherein the voltage range of the set Y of the one or more potential cycles comprises 0.65-0.85V vs SHE or between open circuit potential and 0.85V vs SHE.

7. The method of claim 1, wherein the cleaning of the surface of the UME from the deposition of the one or more organic compounds by passing the gas on the surface of the UME comprises bubbling a hydrogen gas, bubbling an oxygen gas, bubbling a nitrogen gas, or bubbling a chlorine gas on the surface of the UME.

8. The method of claim 1, wherein concentration of the one or more organic compounds in the aqueous medium is between about 0.5-5000 ppm.

9. The method of claim 1, wherein the one or more organic compounds comprise ethylene dichloride, chloroethanol, monochloroacetaldehyde, dichloroacetaldehyde, trichloroacetaldehyde, or combinations thereof.

10. The method of claim 1, wherein the UME is made of gold, platinum, titanium, carbon, conductive polymer, or iridium.

11. The method of claim 1, wherein the metal ion is iron, copper, tin, chromium, or combination thereof.

12. The method of claim 1, wherein the metal ion is a metal halide.

13. The method of claim 1, wherein the concentration of the metal ions in the lower or the higher oxidation state is more than 0.5M or a total metal ions concentration in the aqueous medium is more than 1M.

14. The method of claim 1, further comprising keeping the UME cell at temperature of between 50-100°

C.

15. The method of claim 1, wherein the measurement of the concentration of the metal ions in the lower and/or the higher oxidation state in the aqueous medium is conducted before, during, and/or after administration of the aqueous medium to an anode chamber of an electrochemical cell where the metal ions are oxidized from the lower oxidation state to the higher oxidation state at an anode.

16. The method of claim 1, wherein the measurement of the concentration of the metal ions in the lower and/or the higher oxidation state in the aqueous medium is conducted before, during, and/or after administration of the aqueous medium to a reactor where the metal ions in the higher oxidation state in the aqueous medium are reacted with an unsaturated or saturated hydrocarbon to form one or more organic compounds and the metal ions in the lower oxidation state in the aqueous medium.

17. An ultramicroelectrode (UME) cell, comprising:

a UME cell comprising a UME configured to measure concentration of metal ions in lower and/or higher oxidation state in an aqueous medium comprising one or more organic compounds, wherein the UME cell is configured to subject the UME to a set X of one or more potential cycles to form one or more gases on the surface of the UME and the UME cell is configured to subject the UME to a set Y of one or more potential cycles causing oxidation of the metal ions in lower oxidation state to a higher oxidation state or causing reduction of the metal ions in higher oxidation state to a lower oxidation state.

18. The UME cell of claim 17, further comprising an adsorption unit operably connected to the UME cell comprising an adsorbent configured to adsorb the one or more organic compounds from the aqueous medium.

19. A system configured to measure concentration of metal ions in presence of one or more organic compounds in an aqueous medium comprising:

a UME cell comprising a UME configured to measure concentration of metal ions in an aqueous medium comprising one or more organic compounds; and

the aqueous medium comprising metal ions and the one or more organic compounds,

wherein the UME cell is configured to subject the UME to a set X of one or more potential cycles to form one or more gases on the surface of the UME and the UME cell is configured to subject the UME to a set Y of one or more potential cycles causing oxidation of the metal ions in lower oxidation state to a higher oxidation state or causing reduction of the metal ions in higher oxidation state to a lower oxidation state.

20. The system of claim 19, wherein the one or more gases comprise oxygen gas, chlorine gas, hydrogen gas, sulfur dioxide gas, or combinations thereof.