WSRC-MS-2001-00573

SuperLigÒ 639 Equilibrium Sorption Data for Technetium
from Hanford Tank Waste Supernates

N. M. Hassan, W. D. King, D. J. McCabe, and L. L. Hamm
Westinghouse Savannah River Company
Aiken SC 29808

M. E. Johnson
CH2MHILL Hanford Group, Inc.
Richland, WA 99352

This document was prepared in conjunction with work accomplished under Contract No. DE-AC09-96SR18500 with the U.S. Department of Energy.

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Abstract

SuperLigÒ 639 ion exchange resin is currently being evaluated for technetium (99Tc) removal from radioactive Hanford tank wastes. To assess the performance of the resin in column configuration, a multiple batch contact method was used to determine the equilibrium distribution coefficients (Kd values) and percent removal for technetium (as pertechnetate, TcO4-) from highly alkaline waste solutions obtained from the Hanford Site. The Kd values for Hanford tank wastes AN-103, AZ-102, and AN-102 were 530, 886, and 287 mL/g, respectively. The TcO4- Kd values for the AN-102 mixed with AN-103 after 4 hours and 14 days were 456 and 392 mL/g, respectively. The percent removal of technetium as TcO4- anion from three Hanford tank solutions (AN-103, AZ-102, and AN-102) was higher than 80%, which is required for Hanford waste pretreatment flowshee. The results indicate that SuperLigÒ 639 resin is highly selective for pertechnetate in the presence of relatively high concentrations of nitrate anion.

Introduction

Millions of gallons of high-level radioactive waste (a legacy by-product of the production of nuclear materials for national defense needs during the past 50 years) are stored in underground tanks in the U. S. Department of Energys (DOE) Hanford Site awaiting pretreatment and safe disposal. Numerous processes involving the addition of many chemical reagents resulted in the generation of various waste streams, which were combined in underground storage tanks. The tanks contain varying amounts and types of solids and millions of gallons of aqueous supernate. While all of the supernate is alkaline and contains primarily sodium salts, significant compositional variation is observed between tanks. The major radioactive constituents in the waste are 137CS (t1/2 = 30 y), 99Tc (t1/2 = 2 x106 y), and 90Sr (t1/2 = 29 y), which are primarily responsible for the radioactivity due to their long half-lives and high fission yields. Technetium is primarily present in the supernate as pertechnetate (TcO4-), which is highly soluble in water and readily mobile in the environment [1,2].

The process flowsheet proposed for pretreatment of Hanford tank wastes removes 137Cs, 99Tc (as pertechnetate ion, TcO4-), and 90Sr from the bulk of the waste and concentrates these species into smaller volume streams. The bulk of the decontaminated waste is to be vitrified and disposed as low-activity waste glass. The concentrated radionuclides are to be combined with high-level waste sludge and vitrified into high-level waste glass. To achieve this goal, novel process schemes and suitable ion exchange technologies are continuing to be developed and tested.

Technetium removal from Hanford waste supernates by ion exchange has been widely investigated [3-6]. Various ion exchange materials have shown the ability to remove 99Tc as TcO4- from simulated waste solutions [7-10]. A highly-selective ion exchange resin, developed using molecular recognition technology and macrocyclic chemistry, was very effective at removing pertechnetate from highly alkaline Hanford waste solutions [11]. This resin, designated as SuperLigÒ 639, is currently under consideration as the baseline ion exchange resin for the Hanford Waste Treatment Plant because of its high selectivity for pertechnetate, elutability, and availability in an engineered form that is suitable for use in ion exchange columns.

In support of the flowsheet development for the Hanford Waste Treatment Plant, multiple batch contact tests were performed with SuperLigÒ 639 resin and actual Hanford tank waste supernates. The multiple batch contact method was employed to obtain equilibrium distribution coefficients (Kds) and percent removal (% R) for technetium from tanks 241-AN-103, 241-AZ-102, and 241-AN-102. In addition, the Kds were obtained for solution mixtures of tank 241-AN-103 with 241-AZ-102 and 241-AN-102 as well as for tank 241-AZ-102 with 241-AN-102, after aging the mixed samples for 4 hours and 14 days. The resulting data provided a rapid and cost-effective evaluation of this ion exchange material for technetium removal from complex tank waste solutions and process mixtures.

Experimental

Hanford Tank Waste Samples

Radioactive waste samples from Hanford underground tanks were used for the determination of technetium batch distribution coefficients and percent removal. The samples were retrieved from Hanford tanks 241-AN-103, 241-AZ-102, and 241-AN-102. The prefix "241" is common to all Hanford tanks and will not be used hereafter. The primary compositions of the Hanford tank waste supernates are shown in Table 1. Tank AN-103 waste is characterized by having high alkalinity and high ionic strength. The "as-received" AN-103 sample was diluted to ~5 M Na+ with 0.01 M sodium hydroxide solution and filtered through 0.45-m m nylon filters prior to batch contact testing. The nitrate, free hydroxide, and 99Tc concentrations in the diluted sample were 1.56 M, 1.87 M, and 0.052 mCi/mL, respectively. The "as-received" AZ-102 sample was relatively low in ionic strength (2.65 M Na+) and was not diluted. The sample was filtered through 0.45-m m nylon filters prior to batch contact testing to remove small amounts of entrained solids. The 99Tc concentration (0.267 m Ci/mL) in the filtered AZ-102 sample was higher than the AN-103 sample. The NO3- and free OH- concentrations of the filtrate were 0.27 M and 0.11 M, respectively. Tank AN-102 waste supernate contained relatively high amounts of soluble strontium and transuranics due to the presence of organic complexants (total organic carbon: ~1.9 M).

Table 1. Concentrations of Selected Analytes in the Hanford Tank Waste Supernates

Constituents (M)

Tank AN-103

Tank AZ-102

Tank AN-102

[Na+]

4.99

2.65

5.32

[Al]

8.40E-01

2.79E-02

2.25E-01

[Ca]

2.00E-03

2.70E-03

3.54E-03

[Cr]

1.40E-03

1.48E-02

1.71E-03

[P]

9.9E-03

5.4E-03

2.76E-02

[Si]

3.40E-03

-

3.7E-03

[K+]

1.17E-01

8.10E-02

2.54E-02

[NO3-]

1.56E+00

2.73E-01

1.52E+00

[NO2-]

8.66E-01

8.32E-01

8.47E-01

[SO4-2]

8.0E-03

1.72E-01

6.26E-02

[PO4-2]

6.90E-03

< 3.0E-03

<1.26E-02

[Cl-]

8.50E-02

7.00E-03

3.89E-02

OH- (Free)

1.87E+00

1.09E-01

1.25E+00

TIC*

0.31

0.10

0.65 M

TOC*

0.047

0.026

1.88 M

Density, g/mL

1.27

1.15

1.27

[137Cs], m Ci/mL
total [Cs+], M

200
6.70E-05

1140
2.06E-04

162
4.99E-06

[99Tc], m Ci/mL
[99Tc], M

0.052
3.1E-5

0.267
1.59E-04

0.081
4.82E-05

238U (mg/L)

4.08

6.94

9.65

*Molarity is reported for total moles of carbon since the speciation of the carbon-containing species is unknown.

Prior to batch contact tests, the AN-102 sample was subjected to 90Sr and transuranics removal by precipitation. The sample was then filtered by cross-flow filtration and diluted to approximately 5.98 M Na+ with 0.01 M NaOH filter wash solutions. The NO3-, free OH-, and 99Tc concentrations in the diluted filtrate were 1.52 M, 1.25 M, and 0.081 m Ci/mL, respectively.

Ion exchange material

The ion exchange resin used for technetium removal from Hanford tank solutions was SuperLigÒ 639 (batch # 981015DHC720011) supplied by IBC Advanced Technologies, American Fork, Utah. This resin is a polystyrene based material, which contains a proprietary ligand that selectively removes pertechnetate from high ionic-strength alkaline solutions. It is believed that the resin adsorbs the pertechnetate as an ion pair in its sodium and potassium forms (i.e. NaTcO4 and KTcO4) from the Hanford waste solutions. Similar removal of pertechnetate salts by solvent extraction from alkaline solution using crown ethers has been reported [12,13]. The SuperLigÒ 639 resin was supplied as a 20-70 mesh size range containing no adsorbed species and was used "as received" without pretreatment. The sieve analysis of the resin is shown in Table 2.

Table 2. SuperligÒ 639 Sieve Analysis

wt. of fractions (g)

wt. % of fraction

Mesh size

size (m m)

sample # 1

sample # 2

sample # 1

sample # 2

Avg. wt. %.

30

> 600

4.37

4.169

87.35

67.80

77.57

40

> 425

0.574

0.722

11.47

11.74

11.61

50

> 300

0.035

0.054

0.70

0.88

0.79

70

> 212

0.01

_

0.20

_

0.10

total

5.00

4.945

99.7

98.7

99.2

 

Apparatus

The apparatus used to perform multiple batch contact experiments included an analytical balance (Mettler Toledo, Model AE200) accurate to ± 0.001 g, polyethylene bottles, a Maxi-MixÒ III rotary shaker, (Type M65800) supplied by Barnstead/Thermolyne, Bubuque, IA, and nylon filter units with Nalgene, plastic filter holders obtained from Nalgene Nunc International, Rochester, NY. House-supplied vacuum and a trap assembly were used during sample filtration. The experiments were performed in a shielded cell, allowing remote handling of materials.

Procedure

Hanford Waste Samples

Sorption of pertechnetate by SuperLigÒ 639 resin was studied using a multiple batch contact method. All tests were performed in duplicate. For each test, a known volume of the waste solution (~18 mL) was added into a polyethylene bottle with a known quantity of ion exchange resin (~0.18 g). The solution volume to resin mass ratio (phase ratio) was typically ~100:1. The bottles containing the waste solution and the resin were immediately placed on the Maxi-Mix shaker and gently shaken for 24 ± 1 hours at ambient temperature (26 ± 1°C). Control samples (~18 mL of waste solution) were treated in the same way as duplicate test samples without the addition of resin. The concentration of technetium in control samples was used as the starting initial concentration in the batch contact experiments.

After the contact period, the resin was separated from the sample solution by filtration with 0.45-m m nylon filters. A sub-sample of the filtrate was diluted (10:1) with de-ionized water to reduce the radiation dose rate when the sample was transferred from the hot cell to the analytical laboratories. All dilutions and measurements were performed based on mass and corrected for the density of the solution to ensure accuracy. The concentration of 99Tc was determined before and after contact using inductively coupled mass spectrometry (ICP-MS) following a 100x dilution in 0.5 M nitric acid.

Following the initial batch contact tests described above, two sequential re-contacts were performed on the filtrates collected from prior tests. In the first re-contact test, a known volume (~12 mL) of the filtrate from the initial test was re-contacted with fresh SuperLigÒ 639 resin (~0.12 g). The fresh resin and the filtrate were gently shaken for 24 ± 1 hours. After equilibration, the resin was separated from the solution and filtered with a 0.45-m m nylon filter. A sub-sample of the first re-contact filtrate was removed from the cell and analyzed by ICP-MS to determine the concentration of 99Tc. The second re-contact was performed by gently shaking a known volume (~10 mL) of the first re-contact filtrate with fresh SuperLigÒ 639 resin (~0.1 g) for 24 ± 1 hours. After equilibration, the resin was separated again from the solution by filtration through a 0.45-m m nylon filter. Sub-samples of the filtrate from the second re-contact tests were submitted for analysis as described above.

Following the two sequential batch contact tests, non-radioactive 99Tc (as NaTcO4) was spiked into known volumes of the AN-103 and AN-102 waste solutions. This was done to increase the concentrations of 99Tc in the waste solutions by a factor of ~10 relative to the initial concentrations in the "as-received" samples. The AZ-102 sample was not spiked since the "as-received" sample already contained a high 99Tc concentration. The spiked solutions were stirred periodically for 4 hours in the cell to promote mixing before contacting with the resin. The spiked waste solutions (~10 mL) were gently shaken with fresh SuperLigÒ 639 resin (~0.1 g) for 24 ± 1 hours. Control spiked sample were also treated in identical steps as the duplicate spiked waste samples. After the equilibration period, the solutions were filtered with 0.45-m m nylon filters. Sub-samples of the filtrates were removed from the shielded cell and analyzed for 99Tc by ICP-MS.

Mixed Hanford Waste Samples

Mixtures of Hanford tank waste samples were prepared for batch distribution coefficient measurement. Small aliquots (3.0 ± 0.1 mL) of AN-102 and AZ-102 were each added into separate 30 ± 1 mL samples of AN-103 in 60-mL polyethylene bottles. A small aliquot (3.0 ± 0.1 mL) of AN-102 was also added to 30 ± 1 mL of AZ-102 sample in a 60-mL polyethylene bottle. Upon addition, the solutions were mixed by gently shaking the bottles at 15-minute intervals for 4 hours. Four hours after initial mixing of the solutions, a 24-hour batch contact experiment was initiated to measure TcO4- batch distribution coefficients. Twenty-four hours after initial solution mixing, the solution mixtures were visually examined for foaming, gas bubbling, color change, and visible solids formation. Two weeks after initial mixing of the solutions, a second 24-hour batch distribution coefficient measurement was conducted on each solution. In each test, a known volume of solution mixture (~5 ± 0.1 mL) was added into a polyethylene bottle with a known quantity (~0.05 ± 0.005 g) of SuperLigÒ 639 ion exchange resin to maintain a solution-to-resin ratio of ~100:1 for most tests. The bottles containing the solution and the resin were placed on the orbital shaker and were gently shaken for 24 ± 1 hours at cell ambient temperature (26 ± 1°C). The tests were conducted in duplicate using the same method as previously described. Sub-samples of the filtrate (test and control samples) were analyzed for 99Tc by ICP-MS.

Pretreated Hanford Waste Samples

A batch contact test was conducted on a portion of the AZ-102 sample, which had been treated for cesium removal using SuperLig 644 resin columns. The test was performed in duplicate by adding 5.0 mL of decontaminated AZ-102 solution into 0.05 ± 0.005 g of SuperLigÒ 639 resin. After 24-h equilibration, the solutions were filtered with 0.45-m m nylon filters. Sub-samples of the filtrates were removed from the shielded cell and analyzed for 99Tc by ICP-MS. Control samples of the decontaminated AZ-102 were also treated in identical steps as the duplicate test samples.

Equilibrium Distribution Coefficient (Kd) Calculation

Pertechnetate batch distribution coefficients (Kd's) and percent removal (% R) were calculated using the following equations:

Where, Ci is the initial concentration of pertechnetate ion in control waste samples, Cf is the pertechnetate concentration in test waste samples at equilibrium, V is the volume of test or control waste samples, M is the mass of the "as-received" resin, and F is defined as the mass of dried sample divided by the mass of "as-received" sample. An F-value of 0.987 was determined for SuperLigÒ 639 (batch # 981015DHC720011).

Multiple batch contact experiments were utilized to determine the amounts of unextractable 99Tc (presumed to be technetium species other than pertechnetate) in each waste sample. Based on these experiments, the AN-103, AZ-102, and AN-102 samples are considered to contain 1.6, <0.1, and 63% nonpertechnetate species. Corrections were made to the 99Tc ICP-MS data to adjust the total technetium concentrations to pertechnetate concentrations for each control and batch contact sample. The corrections involved simple subtraction of the amounts of non-pertechnetate determined for each waste sample from the measured total 99Tc values. This method was utilized to determine the Ci and Cf values used in equations 1 and 2.

Results and Discussion

Hanford Waste Samples

A multiple batch contact method was performed with SuperLigÒ 639 resin to determine the distribution coefficients (Kds) for pertechnetate ion with actual Hanford tank solutions (Table 3). A liquid-to-solid ratio of ~100 was used in the batch contact tests and an equilibration time of 24 ± 1 hours was employed. The calculated distribution coefficients are provided in Table 3 for each batch contact test. The equilibrium TcO4- concentrations, Kd, and resin loading values shown are averages of the results from duplicate experiments unless otherwise indicated. Pertechnetate % removals calculated for the initial contacts were approximately 87, 91, and 89 % for the AN-103, AZ-102, and AN-102 samples, respectively. For the AN-102 sample, the % removal for total technetium for the initial contact was <30%, due to the fact that ~60% of the 99Tc was not TcO4-. As seen in Table 1, the Kd values do not directly correspond to resin loadings. For example, the highest overall Kd values were observed for the AZ-102 sample (Figure 1), although resin loading was actually lower for this sample than for the AN-103 or AN-102 samples.

Pertechnetate adsorption isotherms are shown for each waste sample in Figure 2. Resin loading is plotted versus the equilibrium pertechnetate to nitrate ratios in order to normalize the impact of nitrate, which is considered to be the primary competitor with pertechnetate for SuperLigÒ 639 adsorption sites in Hanford waste solutions. As would be expected, pertechnetate loading increases with increasing equilibrium pertechnetate to nitrate ratios, due to the decreased competition of nitrate. The resin performance based on pertechnetate loading in the various waste samples decreased in the following order: AN-103, AN-102, and AZ-102.

Table 3. Pertechnetate Distribution Coefficients for SuperligÒ 639 with Actual Hanford Waste Solutions

Sample

Equilibrium TcO4- (M)

TcO4- Kd
(mL/g)

TcO4- loading
(mmol/g)

Tank AN-103

Spike

4.24 E-05

452

1.92 E-02

Initial contact

3.93 E-06

530

2.06 E-03

1st Recontact

4.86 E-07

714

3.46 E-04

2nd Recontact

8.95 E-08

459

4.08 E-05

Tank AZ-102

Initial contact

1.43 E-05

886

1.27 E-02

1st Recontact

1.21 E-06

982

1.17 E-03

2nd Recontact

1.62 E-07

548

7.98 E-05

3rd Recontact

1.72 E-08

1109

1.11 E-05

Tank AN-102

Spike

6.39 E-05

288

1.83 E-02

Initial contact

5.14 E-06

281

1.43 E-03

1st Recontact

1.21 E-06

332*

4.03 E-04

2nd Recontact

2.00 E-06

NA

NA

*Value calculated from a single batch contact experiment rather than the average of duplicate experimental results.
NA = not applicable; Kd and loading values were not calculated for this experiment because the data
indicated that no technetium was adsorbed to the resin
.

The pertechnetate loading curves for each sample are self-consistent and follow a single curve. The slopes of the loading curves for all three waste samples are quite similar but the curves are slightly offset relative to each other.

The differences between the loading curves could be attributed to changes in the pertechnetate to nitrate selectivity coefficient or to changes in the effective resin capacity between waste samples. The lower loadings observed for the AZ-102 sample indicates that resin performance varies directly with the ionic strength of the solution. This is consistent with the observation that pertechnetate elutes rapidly from SuperLig® 639 resin in deionized water [14]. The resin vendor claims that after elution the resin adsorption sites are not occupied by any adsorbed species, i.e. both sodium nitrate and sodium pertechnetate are removed from the resin at zero ionic strength. These observations are more consistent with the theory that the effective resin capacity, rather than the selectivity, varies with ionic strength.

Hanford Mixed Waste Samples

The ultimate Hanford waste processing strategies may involve blending of various tank waste samples or processing solutions (such as waste tank heels) prior to ion exchange treatment. One of the postulated results of mixing these samples is that pertechnetate ion may be converted to a non- pertechnetate (presumably reduced) form of technetium, thereby decreasing the efficiency of the technetium removal columns.pertechnetate (presumably reduced) form of technetium, thereby decreasing the efficiency of the technetium removal columns. A simple approach to evaluating these effects involves measuring the distribution coefficient values of pertechnetate in waste solution mixtures. Distribution coefficients were determined for 10:1 volume mixtures of the AN-103 sample with the AZ-102 sample and with the AN-102 sample. Additional Kd tests were conducted on a 10:1 volume mixture of AZ-102 with AN-103. Twenty-hour batch contact tests were conducted on the mixtures after 4-hour and 14-day mixing times. Mixing the tank samples did not result in the formation of observable solids or adverse chemical reactions (such as foaming, gas release, or color change) over the 14-day storage period. The blended waste compositions were assumed to be the simple volume-weighted averages of the separate waste samples and no analyses were performed on the mixtures to confirm that unexpected compositional changes had not occurred.

An alternative mechanism for the conversion of pertechnetate to other technetium species might involve the introduction of organic compounds into the waste stream by processes in a waste treatment plant. One such source of organic species is SuperLig® 644 degradation products from columns used for cesium removal. The impact of these organics was evaluated by determining the Kd values of the AZ-102 sample after cesium removal with SuperLig® 644 columns.

Table 3 compares the TcO4- Kds for Hanford mixed waste solutions to those observed for the pure waste solutions. Quantitative prediction of the effects of mixing the waste solutions on the Kd values is not a straight forward process and depends on several factors such as the impact of changes in ionic strength, overall solution composition, pertechnetate concentration, and pertechnetate to total 99Tc ratios. The Kd values for the pure waste samples are included in Table 3 only to provide a basis for evaluating whether shifts observed in the Kd values for the mixed samples relative to the pure samples are in the expected directions.

Table 4. TcO4- Kd Values for Hanford Mixed Waste Samples

Mixed Waste Sample

4-hr Kd

14-day Kd

Pure Waste Kd Values
Major/Minor Component

AN-103/AZ-102 (10:1 v/v)

615

600

530/886

AN-103/AN-102 (10:1 v/v)

456

392

530/281

AZ-102/AN-102 (10:1 v/v)

592

945

886/281


The Kd values determined after 4-hour and 14-day storage periods for solution mixtures of AN-103 with AZ-102 (10:1 v/v) were 615 and 600 mL/g, respectively. Aging the solution for two weeks did not significantly effect the distribution coefficient relative to the value obtained after a 4-hour mixing time. This indicates that there is no slow conversion of pertechnetate to other unextractable technetium species on the time scale of the experiment.

The Kd for the mixed sample was slightly higher than was observed for the pure AN-103 sample, as would be expected based on the higher Kd observed for the AZ-102 sample relative to AN-103. Conversely, the addition of a small amount of AN-102 to AN-103 resulted in a slight decrease in the measured Kd value as would be expected based on the values observed for the pure waste samples. The TcO4- Kd values observed for the AN-102 mixed with AN-103 after 4 hours and 14 days were 456 and 392 mL/g, respectively. This indicates that aging the solution prior to pertechnetate removal may result in a slight decrease (14%) in the resin performance. Figure 3 shows TcO4- equilibrium loading as a function of the equilibrium NO3-/TcO4- molar ratio for the mixed samples predominantly made from AN-103 with AZ-102 or AN-102. As shown, the equilibrium loading of the mixed samples are very consistent with the pure AN-103 sample and the effect of the contact period (4 h vs. 14 days) appears to be minor.

For the mixture of AZ-102 and AN-102, the TcO4- Kd values were 592 and 945 mL/g for the 4-hour and 14-day old solutions. This drastic improvement in resin performance after aging the solution indicates that process hold times may be required to achieve acceptable technetium removal from AZ-102/AN-102 mixtures such as this. Based solely on the Kd values for the pure samples, the Kd of the mixture would be expected to decrease relative to the value observed for the AZ-102 sample (886 mL/g). The increase in the Kd of the 14-day sample indicates that mixing of AZ-102 and AN-102 samples may result in the conversion of non-pertechnetate species in the AN-102 waste to TcO4-. This observation could have significant process impacts. The equilibrium loading of the mixed samples prepared from AZ-102 with AN-102 and pure AZ-102 are plotted in Figure 4 as function of the equilibrium NO3-/TcO4- molar ratio. The loadings of the mixed samples (after 4 h and 14 days) are consistent with the pure as well as cesium decontaminated AZ-102 samples.

Conclusion

A molecular recognition product, referred to as SuperLig® 639 was evaluated for technetium removal from Hanford tank wastes. Multiple batch contact tests were performed on the SuperLig® 639 resin to determine the sorption characteristics of technetium as TcO4- anion from three Hanford tank waste solutions and their mixtures. The resin was found to be very selective for TcO4- removal from a wide range of tank compositions. The pertechnetate batch distribution coefficients for three Hanford tank solutions (AN-103, AZ-102, and AN-102) were significantly higher than a minimum required for Hanford waste pretreatment flowsheet to achieve acceptable decontamination factors for a single pass through the ion exchange columns. There was no indication of adverse effects from mixing of primary tank waste solutions (AN-103 and AZ-102) to process tank heels (AN-102).

Acknowledgment

This work was conducted at the Savannah River Technology Center in Aiken, SC, which is operated for the U. S. Department of energy by Westinghouse Savannah River Company under contract DE-AC09-96SR18500. The Hanford River Protection Project Office supported this work. We are very grateful to Karen N. Palmer, Yvonne J. Simpkins, Francis Wakefield, and Myra Bussey for their assistance in the completion of the experimental work. We also thank Major Thompson for his contributions toward the experimental design and review of this work.

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Figure 1. Pertechnetate Kd Values for Hanford Tank Waste Supernates

 

Figure 2. Pertechnetate Equilibrium Loading for Hanford wWaste Samples on SuperLigÒ 639

Figure 3. Pertechnetate Equilibrium Loading for AN-103 Mixed with AZ-102 or AN-102

 

Figure 4. Pertechnetate Equilibrium Loading for AZ-102 Mixed with AN-102 and Decontaminated AZ-102