atw - International Journal for Nuclear Power | 05.2021

atw Vol. 66 (2021) | Issue 5 ı September
RESEARCH AND INNOVATION 56
against time gives a composite curve
in which the activity initially decreases
sharply and thereafter very
slowly giving nearly straight line,
evidently rapid and slow ion adsorption
reactions were occurring simultaneously
[19]. The activity exchanged
due to rapid, slow uptake reactions as
well as the specific reaction rate (k)
of rapid ion uptake reactions were
calculated in the same way as
explained previously [20-22]. The
amount of bromide ions exchanged
(mmol) on the resin were obtained
from the initial and final activity of
solution and the amount of ions in
200mL of solution.
It was observed that, under identical
experimental conditions, with rise
in temperature from 30.0 °C to 45.0 °C,
the k values (min -1 ) for bromide ion
uptake reactions were observed to decrease
for fresh as well as for λ 384 and
λ 284 photo- degraded resins (Table 1).
Thus for 0.200M bromide ion concentration
when the temperature was
raised from 30.0 °C to 45.0 °C, the k
values decrease from 0.238 to 0.226
min -1 for fresh resin, from 0.198 to
0.181 min -1 for λ 384 photo-degraded
resin and from 0.156 to 0.142 min -1 for
λ 284 photo-degraded resin (Table 1).
It was observed that, under identical
experimental conditions, with rise
in concentration of bromide ions in
the solution from 0.200M to 0.500M,
the k values (min -1 ) for ion uptake
reactions were observed to increase
for fresh as well as for λ 384 and λ 284
photo-degraded resins (Table 2).
Thus at 30.0 °C when the bromide
ion concentration was raised from
0.200M to 0.500M, the k values increase
from 0.238 to 0.276 min -1 for
fresh resin, from 0.198 to 0.223 min -1
for λ 384 photo-degraded resin and
from 0.156 to 0.176 min -1 for λ 284
photo-degraded resin (Table 2).
From the results, it appears that
under identical experimental conditions,
ion uptake reaction rate
decreases sharply as the photodegradation
wavelength decreases
from 384 nm to 284 nm. Thus for
0.200M bromide ion concentration at
a constant temperature of 30.0 °C, the
k value was 0.238 min -1 for fresh
resin, which decreases to 0.198 min -1
for λ 384 photo-degraded resin, which
further decreases to 0.156 min -1 for
λ 284 photo-degraded resin (Table 1).
Comparing the ion uptake reaction
rate (k) in min -1 for reactions
performed at different temperatures
of reaction medium and concentration
of labeled bromide ion solution,
it was observed that the k values
decrease with decrease in photodegradation
wavelength.
Temperature
of reaction
medium
°C
reaction
rate of rapid
isotopic
ion uptake
process
(min -1 )
Fresh resin λ 284 photo degraded resin λ 384 photo degraded resin
Amount
of isotopic
ions uptake
(mmol)
% of
isotopic
ions
uptake
reaction
rate of rapid
isotopic
ion uptake
process
(min -1 )
Amount
of isotopic
ions uptake
(mmol)
% of
isotopic
ion
uptake
reaction
rate of rapid
isotopic
ion uptake
process
(min -1 )
Amount
of isotopic
ion uptake
(mmol)
% of
isotopic
ion
uptake
30.0 0.238 21.9 54.8 0.156 18.4 45.9 0.198 20.2 50.5
35.0 0.233 19.9 49.7 0.152 15.1 37.8 0.19 18.1 45.3
40.0 0.229 17.8 44.6 0.147 11.9 29.7 0.186 16.0 40.1
45.0 0.226 16.1 40.3 0.142 8.6 21.6 0.181 14.0 34.9
Energy of
activation
(kJ.mol -1 )
Enthalpy of
activation
(kJ.mol -1 )
Free energy of
activation
(kJ.mol -1 )
Entropy of
activation
(kJ.K -1 mol -1 )
-2.77 -5.05 -4.66
-5.35 -7.63 -7.24
64.66 63.65 63.86
-0.231 -0.236 -0.234
| Tab. 1.
Effect of temperature of reaction medium on isotopic ion uptake reaction kinetics and isotopic uptake using fresh/photo-degraded Indion GS 300 resins.
Amount of ion exchange resin in bromide form = 1.000 g; Concentration of labeled bromide ion reaction medium = 0.200M; Volume of labeled bromide ion reaction medium = 200 mL;
Amount of exchangeable bromide ions in 200 mL labeled reaction medium = 40.00 mmol.
Concentration
of ions
in the
reaction
medium
(M)
Amount
of ions in
200 mL
labeled
solution
(mmol)
reaction
rate of
rapid
isotopic
ion uptake
process
(min -1 )
Fresh resin λ 284 photo degraded resin λ 384 photo degraded resin
Amount
of isotopic
ion
uptake
(mmol)
% of
isotopic
ion
uptake
reaction
rate of
rapid
isotopic
ion uptake
process
(min -1 )
Amount
of isotopic
ion
uptake
(mmol)
% of
isotopic
ion
uptake
reaction
rate of
rapid
isotopic
ion uptake
process
(min -1 )
Amount
of isotopic
ion uptake
(mmol)
% of
isotopic
ion
uptake
0.200 40.00 0.238 21.9 54.8 0.156 18.4 45.9 0.198 20.2 50.5
0.300 60.00 0.250 35.5 59.2 0.162 29.8 49.6 0.207 32.6 54.4
0.500 100.00 0.276 68.7 68.7 0.176 56.7 56.7 0.223 63.8 63.8
| Tab. 2.
Concentration effect on isotopic ion uptake reaction kinetics and isotopic uptake using fresh/photo-degraded Indion GS 300 resins.
Amount of ion exchange resin = 1.000 g; Volume of labeled ionic reaction medium = 200 mL; Temperature of reaction medium = 30.0 °C.
Research and Innovation
Non-destructive Radioactive Tracer Technique in Evaluation of Photo- degraded Polystyrene Based Nuclear Grade Ion Exchange Material ı Pravin U. Singare