1 / 22

MnO 2 Resin: Concentration of Radium Isotopes

MnO 2 Resin: Concentration of Radium Isotopes. Deok-Soo Moon Bill Burnett Department of Oceanography Florida State University Tallahassee, Florida. Applications in Oceanography. Mixing rates between near-shore and offshore waters Assessment of submarine groundwater discharge.

inara
Télécharger la présentation

MnO 2 Resin: Concentration of Radium Isotopes

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. MnO2 Resin: Concentration of Radium Isotopes Deok-Soo Moon Bill Burnett Department of Oceanography Florida State University Tallahassee, Florida

  2. Applications in Oceanography • Mixing rates between near-shore and offshore waters • Assessment of submarine groundwater discharge

  3. Scale for Laboratory Use • “MnO2 Resin” Developed by PGRF • 80-160 mesh • Preconcentration approach in batch, column, or pump (filtration) modes • High adsorption of Ra, trivalent and tetravalent actinides (Ac, Am, Pu, Th)

  4. MnO2 Resin Experiments • Uptake studies: 133Ba and Ra; batch and column modes; kinetics; optimum conditions • Evaluate difference in chemical behavior, if any, between Ba and Ra • Evaluate use of MnO2 Resin cartridge with pump for processing

  5. Tracers, Analytical Approach • Ba-133 (commercial, nominal activity) • Ra-228 (separated from Th-232 solution) • Ba-133 via g-spect (NaI) and LSC • Ra-228 via Ac-228 separation (Diphonix), HEDPA elution, LSC counting

  6. Batch Experiments • Ba-133 spike, adjust pH, react Mn Resin with measured vol, vary time, resin, pH • Filter using syringe • Measure resin with NaI detector • Measure fluid with LSC • Perform experiments with both deionized water and seawater

  7. Distribution Coefficient Ao = initial activity solution Af = final activity solution V = volume solution W = weight of resin

  8. Kinetics, pH @ 3 • pH = 3 • Resin = 25 mg • Solution = 10 mL

  9. Kinetics, pH = 7 • pH = 7 • Resin = 25 mg • Solution = 10 mL Floridan Aquifer groundwater ~40-200 mg/L (0.04-0.2 o/oo)

  10. Optimize Amount of Resin • pH = 3 or 7 • Resin = variable • Solution = 10 mL DDW • Reaction time = 90 min

  11. pH Variation • pH = variable • Resin = 25 mg • Solution = 10 mL • Reaction time = 90 min

  12. Column Experiments

  13. Column Results • pH = 7 • Resin = 1 g • Solution = 1 liter DDW • Flow rate ~0.65 mL/cm2.min (gravity flow ~1 mL/min)

  14. Pump Tests Peristaltic pump; cartridge loaded with 1 g MnO2 Resin; single pass

  15. Ba Recovery vs Flow Rate • pH = 7 • Resin = 1g • Solution = 1L DDW or SW • Variable flow 96.2±2.7%

  16. Ra Recovery vs Flow Rate • pH = 7 • Resin = 1g • Solution = 1L DDW or SW • Variable flow 95.2±5.1%

  17. Ba/Ra Recovery Ratio • pH = 7 • Resin = 1g • Solution = 1L DDW or SW • Variable flow 1.01±0.05

  18. Summary/Future Work • MnO2 Resin adsorbs Ra and Ba very well • Little difference in uptake between Ra and Ba except in sw • Investigate intermediate salinities (typical groundwaters, etc.) • Mate to RAD-7 radon analyzer for Ra-224 • Study adsorption of Am(III), Th(IV), etc.

  19. RAD-7 For Ra-224 Analysis MnO2 Resin can be put in line with a RAD-7 Rn analyzer to quantify Ra-224 (and Ra-226)

  20. Ra Isotopes via RAD-7 Resin Kim et al., 2001, ES&T, 35, 4680.

  21. MnO2 Resin MnO2 Resin MnO2 Resin Drinking Water monitoring Water Pipe

  22. 224 Ra RAD7 Instant. Beta count. MnO2 Resin 226 Ra 228 Ra Several days RAD7 30 Hours Elution-LSC MnO2 Resin MnO2 Resin Drinking Water monitoring

More Related