Dependence of concentration of CO2, H2O2, pH- indicator and IR-spectra of γ- irradiated transformer oil, containing polychlorinebiphenyl (PCB) admixtures from adsorbed doses in the range of 4-136 kGy was studied. It was established that radiation-chemical yields of CO2 and H2O2 are equal to 0.18 and 3.6 molec/100eV. Irradiation leads to increasing of acidity, related with dechlorination of PCB molecules. A comparative study of the radiolysis of used transformer oil and oil containing PCB under the influence of gamma radiation was carried out. The pH-value dependence and concentration of hydrogen peroxide as a function of the absorbed dose was studied. It found that during the radiolysis of transformer oil containing PCB in the presence of dissolved oxygen, radiation-initiated oxidation of the oil takes place (formation of H2O2 and CO2, a decrease in the pH-value).

1. International Journal of Modern Research in Engineering & Management (IJMREM)
||Volume|| 1||Issue|| 8 ||Pages|| 01-06 || August 2018|| ISSN: 2581-4540
www.ijmrem.com IJMREM Page 1
Radiolysis of Transformer Oil in The Presence of Admixtures of
Polychlorinebiphenyl
1,
Z.I.Isgenderova, 2,
M.A.Gurbanov
Institute of Radiation Problems of Azerbaijan National Academy of Science
AZ 1143, Baku, st. B.Vahabzadeh, 9
--------------------------------------------------------ABSTRACT--------------------------------------------------
: Dependence of concentration of CO2, H2O2, pH- indicator and IR-spectra of γ- irradiated transformer oil,
containing polychlorinebiphenyl (PCB) admixtures from adsorbed doses in the range of 4-136 kGy was studied.
It was established that radiation-chemical yields of CO2 and H2O2 are equal to 0.18 and 3.6 molec/100eV.
Irradiation leads to increasing of acidity, related with dechlorination of PCB molecules. A comparative study of
the radiolysis of used transformer oil and oil containing PCB under the influence of gamma radiation was carried
out. The pH-value dependence and concentration of hydrogen peroxide as a function of the absorbed dose was
studied. It found that during the radiolysis of transformer oil containing PCB in the presence of dissolved oxygen,
radiation-initiated oxidation of the oil takes place (formation of H2O2 and CO2, a decrease in the pH-value).
KEYWORDS: Sovtol-10, PCB, transformer oil, dose rate, radiation-chemical yield, radiation stability, IR-
spectra.
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Date of Submission: Date, 10 August 2018 Date of Accepted: 04August 2018
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I. INTRODUCTION:
PCBs are the one of persistent chemicals, included to Stockholm Convention (SC) on POPs, although the industry
production of PCBs are prohibit since of 90s of the last century, the “cross” pollution of transformers oils, widely
used in energy sector is continues up to date. The are 2 approach to the PCBs containing transformer oils disposal
and cleaning of oils, based on SC requirements: the oil containing more than 50 ppm of PCB have to the phase
out from exploitation then utilization by various technologies [1-4]. The oils containing less than 50 ppm of PCBs
may be returned to exploitation after treatment and decreasing of PCBs content ~ 2 ppm – the standard, accepted
in the many countries.
In this point the investigation of possibility of radiation-chemical treatment cleaning of PCBs containing oils is
important. This study is devoted to establishment of kinetic regularities of oil parameters as pH, indicator,
formation of CO2, H2O2, hydrocarbon gases and IR spectra at different adsorbed doses.
II. EXPERIMENTAL
Used transformer oil T-1500, production of a refinery plant named after G. Aliyev in Azerbaijan. PCB has 209
isomers, but "Sovtol-10" contains basically ~50-60 isomers of three, tetra-pentachlorobiphenyls and 10 wt. % -
trichlorobenzene. The oil samples were irradiated by γ- rays from isotope Co60
at static conditions and in glass
ampoules with volume 15 ml in the presence of adsorbed oxygen. The dose rate was determined by the method
of ferrosulfate dosimetry and was 0,21 Gy/s. pH - measurements were provided by Instruction Manual of Basic
pHS-25 pH- meter. Analysis of gases products was provided by gas chromatography Agilent Technology-7890 A
with detectors: FID-hydrocarbons, TCD-carbon oxides (CO, CO2). H2O2 analysis was carried out by a
permanganatometric method. IR- spectra were registered on Fure- Spectrometer Varion-640 in the range 4000-
400 cm-1
. The spectra of the samples irradiated at different doses are treated under the same conditions in the form
of thin films between two plates of KRS-5; the relative intensities (Jmax|J0) of the absorption bands are calculated
and their dose dependences are obtained, where J0 and J are the intensities of absorption bands of unirradiated and
γ irradiated samples, respectively.
III. RESULTS
Two series of experiments were carried out, in which concentration dependence of CO2, H2O2 and pH value in
the used transformer oil, without PCB as a function of the absorbed dose (series 1), and the dose dependence of
above parameters during radiolysis of used transformer oil, containing 5-40 ppm PCB (series 2) was studied.
According to [5], the oxygen content in air dissolved in transformer oil is 30.2%. In the experiments of the series
1, it was found that the pH of the used oil decreases with increasing dose, which is due to the formation of acids

2. Radiolysis of Transformer Oil in The Presence…
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during irradiation. Used oil also contains products of an acidic nature, but their formation significantly increases
with increasing irradiation dose. The formation of hydrogen peroxide, depending on the dose, which has a
maximum at ~ 27 kGy is observed. With a further dose increase, the concentration of H2O2 decreases, which
indicates the course of secondary reactions with its participation. The maximum of CO2 concentration at 27.4 kGy
is observed in the kinetic curve, and the radiation-chemical yield is 0,18 molec /100 eV. Figure 1 shows the
dependence of acidity on the absorbed dose in the range up to 70 kGy for radiolysis of used transformer oil.
As can be seen from the figure, the pH value decreases with increasing absorbed dose, and by relatively
high concentration of PCB, this decrease becomes distinctly: at a PCB concentration of 5 ppm, the pH decreases
from 5.5 to 2.1 (62%), at PCB 40 ppm from 5.0 to 1.6 (68%). Figure 2 shows concentration dependence of CO2
from the absorbed dose at different initial concentrations of PCB in transformer oil.
Figure 3 shows concentration dependence of H2O2 as a function of the absorbed dose at different initial
concentrations of PCB in transformer oil.
0
2
4
6
8
10
12
14
0 20 40 60 80 100 120 140
Fig. 1. Dependence of the acidity in transformer oil as of the absorbed dose at different
initial PCB concentrations in the range of 5-40 ppm
- 5 ppm, - 15 ppm, - 40 ppm
pH
D, kGy0
1
2
3
4
5
6
0 50 100 150
NCO21017molek/q
D, kQr
Fig. 2. Concentration dependence of CO2 as a function of the absorbed dose at different
initial concentration of PCB in transformer oil.
- 5 ppm, - 15 ppm, - 40 ppm

3. Radiolysis of Transformer Oil in The Presence…
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It can be seen that the concentration of CO2 and H2O2 increases and reaches a steady-state
concentration with dose increasing. The steady-state concentration is achieved at a dose range 4.1-10
kGy. Further growth of the absorbed dose leads to a decrease of the concentration of both products.
From the initial parts of the kinetic curves, the radiation-chemical yields of formation of CO2 and H2O2 are
determined, which are given in Table 1.
Table 1. Radiation-chemical yields of H2O2, CO2 and pH values at different initial concentrations of PCB in
transformer oil.
СPCB, ppm
G, molec/100eV
H2O2 CO2
0 3,6 0,18
5 3,9 1,1
15 4,7 1,9
40 5,9 2,3
As can be seen from the table, the radiation-chemical yield of CO2 and H2O2 increases with increasing of PCB
concentration. The related wiht oxidation process and the formation of acid products during the radiolysis of
transformer oil in the presence of PCB. Along with oxidation processes, the molecules of transformer oil
components undergo decomposition under the action of ionizing radiation, which leads to the formation of gaseous
products - hydrogen and hydrocarbons. Hydrogen and hydrocarbon products as H2, CH4, C2H4, C2H6 have been
identified.
Table 2. Radiation-chemical yields of gaseous products at different initial concentrations of PCB in transformer
oil.
СPCB, ppm
G, molec/100eV
H2 CH4 C2H4 C2H6
0 0,375 0,65 *10-3
0,3*10-3
0,13*10-3
5 0,24 0,47*10-3
0,29*10-3
0,19*10-3
15 0,35 0,44*10-3
0,15*10-3
0,11*10-3
40 0,41 0,51*10-3
0,20*10-3
0,12*10-3
As can it be seen from the table molecular hydrogen is formed with the higher radiation-chemical yield, which
slightly increases with the growth of PCB concentration in transformer oil. The radiation-chemical yield of the
D, kQr
N(H2O2)10-5, q/ml
0
4
8
12
0 50 100 150
Fig. 3. Concentration dependence of H2O2 as a function of the absorbed dose at different
initial concentrations of PCB in transformer oil.
- 5 ppm, - 15 ppm, - 40 ppm

4. Radiolysis of Transformer Oil in The Presence…
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remaining identified gaseous products is less than 10-4
molec / 100 eV, although the tendency of growth of the
radiation-chemical yield with increasing PCB concentration in oil also occurs for these products. Radiolytic
decomposition of polychlorobiphenyl in transformer oil mainly occurs in reactions with solvated electrons due to
high electron affinity of the molecules of PCB, which is typically for chlorogenic compounds. [7] Below given
the rate constants of solvated electrons with molecules of chlorine-containing aromatic compounds and oxygen.
Table 3. The rate constants of the esolv. with molecules of chlorogenic compounds. [1], [4], [6], [7].
Chlororganic compounds and oxygen Rate constants, M-1
s-1
Chlorbiphenils (КС 300, КС 400) 109
-1010
Dichlorobiphenyl 3,8·109
Tetrachlorobiphenyl 3·109
Decahlorobiphenyl 7·109
O2 2·1010
At a concentration of PCB in oil equal to 40 ppm, the ratio of the rates of the electron capture by the molecules of
PCB and oxygen under the experimental conditions is:
𝜔1
𝜔2
=
𝑘1 [𝑃𝐶𝐵]
𝑘2[𝑂2]
=
1 ∙ 109
∙ 2,2 ∙ 10−4
2 ∙ 1010 ∙ 2,97 ∙ 10−4
~3 ∙ 10−2
Calculation shows that electrons are mainly captured by oxygen and the expected yield of the PCB molecules
decomposition is approximately 10-2
of the radiation-chemical yield of the esolv, that was observed. Chemical
changes at PCB radiolysis is shown also by the IR- spectroscopy. In fig. 4. the IR-spectra of irradiated PCB
samples at various adsorbed doses in the range to 136,8 kGy were presented.
3853.462 0.055
3593.480 1.975
3053.019 128.321
1555.647 2.020
1453.140 9.778
1382.895 1.058
1244.694 0.784
1176.451 1.009
1137.297 2.025
1095.467 3.010
1031.675 2.678
884.839 3.122
814.539 4.416
634.493 0.988
(2)
3800 3600 3400 3200 3000 2800 2600 2400 2200 2000 1800 1600 1400 1200 1000 800 600
1.3
1.2
1.1
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
Wavenumber
Absorbance
3853.462 0.055
3593.480 1.975
3053.019 128.321
1555.647 2.020
1453.140 9.778
1382.895 1.058
1244.694 0.784
1176.451 1.009
1137.297 2.025
1095.467 3.010
1031.675 2.678
884.839 3.122
814.539 4.416
634.493 0.988
(2)
3800 3600 3400 3200 3000 2800 2600 2400 2200 2000 1800 1600 1400 1200 1000 800 600
1.3
1.2
1.1
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
Wavenumber
Absorbance
(1)
2956.370 -1.149
2068.263 -0.001
3966.039 6.871
3143.899 41.195
2923.182 6.540
2853.694 -39.656
1462.203 7.399
1376.415 2.563
774.301 1.280
(2)
3800 3600 3400 3200 3000 2800 2600 2400 2200 2000 1800 1600 1400 1200 1000 800 600 400
2.2
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
Wavenumber
Absorbance
2956.370 -1.149
2068.263 -0.001
3966.039 6.871
3143.899 41.195
2923.182 6.540
2853.694 -39.656
1462.203 7.399
1376.415 2.563
774.301 1.280
(2)
3800 3600 3400 3200 3000 2800 2600 2400 2200 2000 1800 1600 1400 1200 1000 800 600 400
2.2
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
Wavenumber
Absorbance
(2)

5. Radiolysis of Transformer Oil in The Presence…
www.ijmrem.com IJMREM Page 5
2950.585 -0.853
3979.802 6.224
3141.227 2.894
2921.099 6.079
2852.317 4.488
2375.126 0.909
2146.420 27.741
1461.923 10.352
1376.415 3.200
971.361 0.645
(8)
3800 3600 3400 3200 3000 2800 2600 2400 2200 2000 1800 1600 1400 1200 1000 800 600 400
1.2
1.0
0.8
0.6
0.4
0.2
0.0
Wavenumber
Absorbance
2950.585 -0.853
3979.802 6.224
3141.227 2.894
2921.099 6.079
2852.317 4.488
2375.126 0.909
2146.420 27.741
1461.923 10.352
1376.415 3.200
971.361 0.645
(8)
3800 3600 3400 3200 3000 2800 2600 2400 2200 2000 1800 1600 1400 1200 1000 800 600 400
1.2
1.0
0.8
0.6
0.4
0.2
0.0
Wavenumber
Absorbance
(3)
3204.357 89.208
2951.924 3.222
2921.010 15.882
2853.136 6.272
2160.359 23.343
1457.309 12.053
1376.051 3.492
971.565 0.910
(9)
3800 3600 3400 3200 3000 2800 2600 2400 2200 2000 1800 1600 1400 1200 1000 800 600 400
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0
-0.2
Wavenumber
Absorbance
3204.357 89.208
2951.924 3.222
2921.010 15.882
2853.136 6.272
2160.359 23.343
1457.309 12.053
1376.051 3.492
971.565 0.910
(9)
3800 3600 3400 3200 3000 2800 2600 2400 2200 2000 1800 1600 1400 1200 1000 800 600 400
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0
-0.2
Wavenumber
Absorbance
(4)
2952.826 1.879
3215.735 136.430
2923.056 4.706
2853.886 4.175
2376.778 4.242
2159.507 38.443 1455.959 4.835
1375.873 1.498
971.237 1.044
(10)
3800 3600 3400 3200 3000 2800 2600 2400 2200 2000 1800 1600 1400 1200 1000 800 600
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
-0.1
-0.2
Wavenumber
Absorbance
2952.826 1.879
3215.735 136.430
2923.056 4.706
2853.886 4.175
2376.778 4.242
2159.507 38.443 1455.959 4.835
1375.873 1.498
971.237 1.044
(10)
3800 3600 3400 3200 3000 2800 2600 2400 2200 2000 1800 1600 1400 1200 1000 800 600
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
-0.1
-0.2
Wavenumber
Absorbance
(5)
2949.871 2.324
3215.093 128.432
2923.356 7.201
2853.129 5.233
2363.072 0.275
2200.737 0.619
2164.909 4.987
1458.071 11.750
1376.033 3.598
(12)
3800 3600 3400 3200 3000 2800 2600 2400 2200 2000 1800 1600 1400 1200 1000 800 600 400
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
-0.1
-0.2
Wavenumber
Absorbance
2949.871 2.324
3215.093 128.432
2923.356 7.201
2853.129 5.233
2363.072 0.275
2200.737 0.619
2164.909 4.987
1458.071 11.750
1376.033 3.598
(12)
3800 3600 3400 3200 3000 2800 2600 2400 2200 2000 1800 1600 1400 1200 1000 800 600 400
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
-0.1
-0.2
Wavenumber
Absorbance
(6)

6. Radiolysis of Transformer Oil in The Presence…
www.ijmrem.com IJMREM Page 6
The following bonds were identified in the IR- spectra =C-H (λ ~3030 cm-1
) –C=C- (1600-1500 cm-1
), =C-H (860-
690 cm-1
), =C-Cl (900-500 cm-1
) [8]. The intensity of bonds of –C=C is decreasing by the dose raising. The
reallocation of bonds in the range at ~1000-1800 cm-1
was observed. The same takes places in the range 500-900
cm-1
, related to –C-Cl.
REFERENCES
1. Getoff N., Solar S. (1988) Radiat. Phys. Chem. 31: 121-130.
2. Chaychian M., Silverman J., Al-Sheikly M. (1999) Environmental Scientific Technologies. 33: 2461-2464.
3. Huang S. K., Hsieh L.L., Chen C.C., Lee P.H, Hsieh B.T. (2009) Applied Radiation and Isotopes 67:493-
1498.
4. Trifan A., Calinescu I., Martin D. (2009) Rev. Chim. 60:1053-1055.
5. Solubility of gases in transformer oil. leg.co.ua/transformatori Heoriya/rastvorimost qazov-v-
transformatornom-masle.html
6. Sawai T., Shimokawa T., Shinozaki Y. (1974) Bulletin of Chemical Society of Japan. 47: 1889-1893
7. Chaychian M., Johnes C., Poster D., Silvermann J., Neta P., Huie R., Al-Sheikhly M. (2002) Radiation
Physics and Chemistry, 65: 473-478
8. Tarasevich B.N. (2012) IR- spectra of main organic compounds, Moscow.
2949.832 1.595
3256.614 3.346
3234.891 7.130
2922.930 5.636
2852.593 4.326
2220.373 13.746
1461.573 11.892
1376.331 3.817
(13)
3800 3600 3400 3200 3000 2800 2600 2400 2200 2000 1800 1600 1400 1200 1000 800 600 400
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
-0.1
-0.2
Wavenumber
Absorbance
2949.832 1.595
3256.614 3.346
3234.891 7.130
2922.930 5.636
2852.593 4.326
2220.373 13.746
1461.573 11.892
1376.331 3.817
(13)
3800 3600 3400 3200 3000 2800 2600 2400 2200 2000 1800 1600 1400 1200 1000 800 600 400
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
-0.1
-0.2
Wavenumber
Absorbance
(7)
Fig. 4. IR-spectra of oil samples at various adsorbed doses (1- Sovtol; 2-transformer oil; 3-
oil+15ppm PCBs; 4- D=4.1; 5- D=27.4; 6- D=68.4; 7- D=136.8 kGy, 15 ppm PCBs in oil)