Method of purifying the used O-18 enriched cyclotron target water and apparatus for the same

• US 20080187087A1
• Filed: 05/31/2007
• Published: 08/07/2008
• Est. Priority Date: 02/02/2007
• Status: Active Grant

• Current Assignee: Korea Atomic Energy Research Institute (Government of The Republic of Korea)
• Original Assignee: Korea Atomic Energy Research Institute (Government of The Republic of Korea)
• Inventors: Kim, Taek Soo, Kim, Jae Woo, Kim, Sang Wook, Bae, Se Won
• Granted Patent: US 7,659,522 B2
• Time in Patent Office: Days
• US Class Current: 376/195
• CPC Class Codes: H05H 7/00 Details of devices of the types covered by groups H05H9/00, H05H11/00, H05H13/00

Abstract

A method of purifying the used O-18 enriched cyclotron target water contaminated by the various organic compounds, the method including: supplying gaseous oxygen into the target water to be purified; irradiating UV rays having wavelengths of 254 nm and 185 nm on the target water; and releasing the gases generated during the purification oxidation process.

Claims

1. A method of purifying the used O-18 enriched cyclotron target water contaminated by the various organic compounds, the method comprising:

supplying gaseous oxygen into the target water to be purified;

irradiating UV rays having wavelengths of 254 nm and 185 nm on the target water; and

releasing the gases generated during the purification process by oxidation.

2. The method of claim 1, wherein, in the supplying gaseous oxygen, the gaseous oxygen is supplied to maintain concentration of dissolved oxygen at 10 to 40 ppm in the target water.

3. The method of claim 1, wherein, in the supplying gaseous oxygen, the gaseous oxygen is supplied by bubbling in the target water.

4. The method of claim 1, wherein, in the supplying gaseous oxygen, the gaseous oxygen is supplied by connecting the oxygen gas line directly to the sample delivery tube before entering the UV irradiator.

5. The method of claim 1, wherein the irradiating UV comprises:

generating intermediate by-products by one of C—

H bond and C—

C bond disassociation caused by irradiation of the UV rays having the wavelengths of 254 nm and 185 nm;

generating —

OH radicals from water molecules and reactive oxygen species (ROS) from the dissolved oxygen supplied into the sample under irradiation of the UV rays having the wavelength of 185 nm; and

generating CO₂ and H₂O as a result of oxidation reaction of the —

OH radicals and the ROS with the intermediate by-products of the organic compounds.

6. The method of claim 5, wherein the irradiating UV further comprises generating ozone O₃ acting as a catalysis for purification of the organic compounds by reaction of the ROS with the dissolved oxygen.

7. The method of claim 1, wherein the method is further comprising a process cooling the sample by heat exchange to maintain a constant temperature of the target water.

8. An apparatus for purifying the used O-18 enriched cyclotron target water contaminated by the various organic compounds, the apparatus comprising:

a reservoir for containing the target water;

a UV irradiator irradiating UV rays on the target water transferred from the reservoir;

a heat exchanger cooling the target water of a high temperature, transferred from the UV irradiator;

a spectroscopic part measuring concentration of the organic impurities in the target water transferred from the UV irradiator; and

a peristaltic pump circulating the target water,

wherein the target water in a tube receives gaseous oxygen in the reservoir, flows out from the reservoir through the UV irradiator, the heat exchanger, and the spectroscopic part, and flows into the reservoir again.

9. The apparatus of claim 8, wherein the reservoir comprises an oxygen supplier supplying gaseous oxygen, a temperature sensor, and a pH meter.

10. The apparatus of claim 8, wherein the reservoir is a flask including three mouths.

11. The apparatus of claim 8, wherein the UV irradiator comprises at least one UV generator generating UV rays having wavelengths of 254 nm and 185 nm, selected from a group consisting of a low pressure mercury lamp and a Xenon Eximer lamp,

wherein a transparent quartz cell through which the target water passes is installed close to the UV generator.

12. The apparatus of claim 11, wherein the transparent quartz cell is installed to be wound helically around the UV generator.

13. The apparatus of claim 11, wherein an inside diameter of the transparent quartz cell is less than 2 mm and a thickness of a cell wall of the transparent quartz cell is less than 1 mm.

14. The apparatus of claim 8, wherein the heat exchanger maintains a temperature of the target water at 10 to 20°

C.

15. The apparatus of claim 8, wherein the spectroscopic part comprises an UV-VIS spectrometer and a quartz flow cell for monitoring the target water.

16. The apparatus of claim 8, wherein the spectroscopic part further comprises at least one selected from a group consisting of a Fourier Transform infrared spectrometer and a gas chromatography.

17. The apparatus of claim 8, wherein the tube is at least one selected from a group consisting of a stainless steel tube and a chemical resistive Tygon tube.