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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. - PowerPoint PPT Presentation
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MnO2 Resin: Concentration of Radium Isotopes
Deok-Soo MoonBill Burnett
Department of OceanographyFlorida State University
Tallahassee, Florida
Applications in Oceanography
Mixing rates between near-shore and offshore waters
Assessment of submarine groundwater discharge
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)
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
Tracers, Analytical Approach
Ba-133 (commercial, nominal activity)
Ra-228 (separated from Th-232 solution)
Ba-133 via -spect (NaI) and LSC Ra-228 via Ac-228 separation
(Diphonix), HEDPA elution, LSC counting
Batch ExperimentsBa-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
Distribution Coefficient
W
V
A
AAD
f
fo
Ao = initial activity solution
Af = final activity solution
V = volume solution
W = weight of resin
Kinetics, pH 3
• pH = 3• Resin = 25 mg• Solution = 10
mL
Kinetics, pH = 7
• pH = 7• Resin = 25 mg• Solution = 10
mL
-20 0 20 40 60 80 100 120 140 160
200
400
600
800
1000
1200
DDW SW (35) ISW (3.5) GW (0.2)
pH=7, 25mg Mn resin
Kd=2.8x104
133 B
a A
ctiv
ity (
CP
M-N
aI)
Time (min)
Floridan Aquifer groundwater ~40-200 mg/L (0.04-0.2 o/oo)
Optimize Amount of Resin
• pH = 3 or 7• Resin =
variable• Solution = 10
mL DDW• Reaction time
= 90 min
0 20 40 60 80 100
200
400
600
800
1000
1200
133 B
a a
ctiv
ity in
Mn
O2
resi
n (
cpm
)
Weight of Mn resin (mg)
pH=3 pH=7
pH Variation
• pH = variable• Resin = 25 mg• Solution = 10
mL• Reaction time
= 90 min
0 2 4 6 8 10 12 14
0
200
400
600
800
1000
1200
DDW SW
133 B
a a
ctiv
ity in
Mn
O2
resi
n (
CP
M)
pH
Column ExperimentsW ater
sam p le1 L
A d d B a & R a trace r1 3 3 22 8
A d ju st p H = 7
M n res inC o lu m n
1 .0 g L eac h w ith 2 M H C l/H O2 2
1 3 3B a Yie ld w ith N aI d e te c to r
A g in g > 3 0 h rs : A c2 2 8
2 M H C l L o ad , R in se 1 M H E D PA 5 .0 m l
D ip h o n ix res in
H E D PA + C o ck ta ilC o u n t L S C A C2 2 8
Column Results
0
2 0
4 0
6 0
8 0
1 0 0
1 2 0
T e s t1 T e s t2
C o lumn E xp e rime nt(F lo w ra te = 1 .0 ml/min, p H = 7 )
Rec
over
y(%
)
BaRa
• pH = 7• Resin = 1 g• Solution = 1
liter DDW• Flow rate 0.65
mL/cm2.min (gravity flow 1 mL/min)
Pump Tests
Peristaltic pump; cartridge loaded with 1 g MnO2 Resin;
single pass
Ba Recovery vs Flow Rate
0 50 100 150 200 250 3000
20
40
60
80
100
120
DDW (pH=7) SW (pH=7)
133 B
a r
eco
very
(%
)
Flow rate (ml/min)
96.22.7%• pH = 7• Resin = 1g• Solution =
1L DDW or SW
• Variable flow
Ra Recovery vs Flow Rate
0 50 100 150 200 250 30020
40
60
80
100
DDW(pH=7) SW (pH=7)
228 R
a r
eco
very
(%
)
Flow rate (ml/min)
• pH = 7• Resin = 1g• Solution =
1L DDW or SW
• Variable flow
95.25.1%
Ba/Ra Recovery Ratio
0 50 100 150 200 250 3000.0
0.2
0.4
0.6
0.8
1.0
1.2
DDW SW
133 B
a/22
8 Ra
re
cove
ry r
atio
Flow rate (ml/min)
• pH = 7• Resin = 1g• Solution =
1L DDW or SW
• Variable flow
1.010.05
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.
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)
Ra Isotopes via RAD-7
MnO2-Fiber(226,228,224,223Ra)
Alpha Detector
- - -
222Rn 220Rn 219Rn
222Rn, 220Rn, 219Rn
215Po216Po
214Po
218Po
Dri
erite
Air
Pum
p
RAD7
Kim et al., Fig. 2
Kim et al., 2001, ES&T, 35, 4680.
Resin
Drinking Water monitoring
Water Pipe
MnO2 Resin
MnO2 Resin
MnO2 Resin
Drinking Water monitoring
MnO2 Resin RAD7 224 224 RaRaInstant.
MnO2 Resin RAD7 226 226 RaRaSeveral days
MnO2 Resin
Beta count.
Elution-LSC
228 228 RaRa30 Hours