Supporting Information to the Article
PHOTOCHEMICAL OXIDATION OF CHLORIDE-ION BY OZONE IN
ACID AQUEOUS SOLUTION
Alexander V. Levanov,*,a Oksana Ya. Isaykina,b Nazrin K. Amirova,a Ewald E. Antipenko,a
Valerii V. Lunina,b
a
Department of Chemistry, M.V. Lomonosov Moscow State University, Leninskiye Gory 1,
building 3, 119991 Moscow (Russia)
b
A.V. Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, Leninsky
prospect 29, 119991 Moscow (Russia)
* Corresponding Author. E-mail address: levanov@kge.msu.ru; Fax: (+7) 495-939-4575; Phone:
(+7) 495-939-3685
70
(dnCl2/dt)/V, mmole L-1 min -1
60
50
40
30
20
10
0
0
5
10
15
C(O3),
20
25
30
g/m3
Fig. S1. Effect of ozone concentration in initial gases on chlorine emission rate. Points are the
experimental data. Lines represent the results of model calculations: black solid line – reactions
(R1-R17), HO3 = 0.24, kLa = 0.3 s–1; red solid line – reactions (R1-R17), HO3 = 0.16, kLa = 0.4 s–
1
; black dashed line – reactions (R1-R10, R12-R16, R18), HO3 = 0.24, kLa = 0.3 s–1, k18 = 7.15 ×
105 s–1, n18 = 1.0725; red dashed line – reactions (R1-R10, R12-R16, R18), HO3 = 0.16, kLa = 0.4
s–1, k18 = 2.26 × 106 s–1, n18 = 1.107. Concentrations in reaction solution [H+] = 0.1 М, [Cl–] = 1
М, [Na+] = 0.9 М.
14
(dnClO3-/dt)/V, mmole L-1 min -1
12
10
8
6
4
2
0
0
5
10
15
C(O3),
20
25
30
g/m3
Fig. S2. Effect of ozone concentration in initial gases on chlorate formation rate. Points are the
experimental data. Lines represent the results of model calculations: black solid line – reactions
(R1-R17), HO3 = 0.24, kLa = 0.3 s–1; red solid line – reactions (R1-R17), HO3 = 0.16, kLa = 0.4 s–
1
; black dashed line – reactions (R1-R10, R12-R16, R18), HO3 = 0.24, kLa = 0.3 s–1, k18 = 7.15 ×
105 s–1, n18 = 1.0725; red dashed line – reactions (R1-R10, R12-R16, R18), HO3 = 0.16, kLa = 0.4
s–1, k18 = 2.26 × 106 s–1, n18 = 1.107. Concentrations in reaction solution [H+] = 0.1 М, [Cl–] = 1
М, [Na+] = 0.9 М.
50
45
(dnCl2/dt)/V, mmole L-1 min -1
40
35
30
25
20
15
10
5
0
0
0,2
0,4
0,6
0,8
1
[H+], M
Fig. S3. Effect of H+ concentration in reaction solution on chlorine emission rate. Points are the
experimental data. Lines represent the results of model calculations: black solid line – reactions
(R1-R17), HO3 = 0.24, kLa = 0.3 s–1; red solid line – reactions (R1-R17), HO3 = 0.16, kLa = 0.4 s–
1
; black dashed line – reactions (R1-R10, R12-R16, R18), HO3 = 0.24, kLa = 0.3 s–1, k18 = 7.15 ×
105 s–1, n18 = 1.0725; red dashed line – reactions (R1-R10, R12-R16, R18), HO3 = 0.16, kLa = 0.4
s–1, k18 = 2.26 × 106 s–1, n18 = 1.107. Ozone concentration in initial gases 10.4 g/m3;
concentrations in reaction solution [Cl–] = 1 М, [H+] + [Na+] = 1 М.
4
(dnClO3-/dt)/V, mmole L-1 min -1
3,5
3
2,5
2
1,5
1
0,5
0
0
0,2
0,4
0,6
0,8
1
[H+], M
Fig. S4. Effect of H+ concentration in reaction solution on chlorate formation rate. Points are the
experimental data. Lines represent the results of model calculations: black solid line – reactions
(R1-R17), HO3 = 0.24, kLa = 0.3 s–1; red solid line – reactions (R1-R17), HO3 = 0.16, kLa = 0.4 s–
1
; black dashed line – reactions (R1-R10, R12-R16, R18), HO3 = 0.24, kLa = 0.3 s–1, k18 = 7.15 ×
105 s–1, n18 = 1.0725; red dashed line – reactions (R1-R10, R12-R16, R18), HO3 = 0.16, kLa = 0.4
s–1, k18 = 2.26 × 106 s–1, n18 = 1.107. Ozone concentration in initial gases 10.4 g/m3;
concentrations in reaction solution [Cl–] = 1 М, [H+] + [Na+] = 1 М.
50
4
Experiment
Experiment
45
3,5
40
(dnClO3-/dt)/V, mmol L-1min -1
(dnCl2/dt)/V, mmol L-1min -1
3
35
30
25
HO3 0.16
20
15
HO3 0.24
HO3 0.24
2,5
HO3 0.16
2
1,5
1
10
0,5
5
0
0
-3
-2
-1
0
1
2
log10(kLa, s-1)
3
4
5
-3
-2
-1
0
1
2
3
4
5
log10(kLa, s-1)
Fig. S5. Effect of the magnitude of volumetric mass transfer coefficient kLa on calculated rates of
chlorine emission and chlorate formation. Kinetic calculations have been performed with the set
of reactions (R1 – R17). Experimental conditions: concentrations in reaction solution [H+] = 0.8
М, [Cl–] = 1 М, [Na+] = 0.2 М, ozone concentration in initial gases 10.4 g/m3, the number of
photons absorbed per unit volume of reaction solution (4.34 ± 0.06) × 1020 photons L−1 min−1.
2,5E+6
1,11
HO3 0.16
1,1
2,0E+6
1,09
n18
k18, s-1
1,5E+6
1,08
1,0E+6
HO3 0.16
1,07
HO3 0.24
5,0E+5
1,06
HO3 0.24
0,0E+0
1,05
0
1
2
3
4
0
1
kLa, s-1
2
3
4
kLa, s-1
Fig. S6. Optimized values of the kinetic parameters of process (R18), k18 and n18, as functions of
Henry’s law constant of ozone HO3 and volumetric mass transfer coefficient kLa. Kinetic
calculations have been performed with the set of reactions (R1 – R10, R12 – R16, R18).
Experimental conditions: concentrations in reaction solution [H+] = 0.8 М, [Cl–] = 1 М, [Na+] =
0.2 М, ozone concentration in initial gases 10.4 g/m3, the number of photons absorbed per unit
volume of reaction solution (4.34 ± 0.06) × 1020 photons L−1 min−1.For kLa ≤ 0.1 s–1 at HO3 =
0.24 and kLa ≤ 0.2 s–1 at HO3 = 0.16, it is impossible to get the agreement between the
experimental and calculated rates by increasing the parameter k18.
Table S1. Reactions R1 – R17 included in the mechanism of photochemical oxidation of aqueous chloride ion by ozone.
#
R1
R2
R3
R4
Irreversible reactions
O3 + hν → O(1D) + O2
O(1D) + H2O → 2OH
O(1D) + H2O → H2O2
Cl– + O3 → ClO– + O2
R10
R11
R12
R13
R14
R15
R16
R17
Cl2 + H2O2 → 2Cl– + O2 + 2H+
Cl2– + H2O2 → 2Cl– + HO2 + H+
Cl2 + HO2 → Cl2– + H+ + O2
Cl2O2 + H2O → Cl– + ClO3– + 2H+
ClO + ClO → Cl2O2
Cl2– + O3 → ClO +Cl– + O2
ClO + H2O2 → HOCl + HO2
ClO + HO2 → HOCl + O2
#
Reversible reactions
R5
R6
R7
R8
R9
Rate constant
4.57 × 10−2 s−1 (see footnote #3 in the main text)
k = φOH × 1.0 × 1012 s−1; φOH = 0.05 (Reisz et al. 2003)
k = φH2O2 × 1.0 × 1012 s−1; φH2O2 = 0.9 (Reisz et al. 2003)
(1.80 × 10–3+1.56 × 10–2[H+])/(1+9.07 × 10–2[H+][Cl–]) L mol−1 s−1
(Levanov et al. 2012; Levanov et al. 2003) (see footnote #4 in the main text)
183.3/(1+2.27[H+][Cl–]) L mol−1 s−1 (Connick 1947)
6.50 × 105 L mol−1 s−1 (Yu 2004)
1.00 × 109 L mol−1 s−1 (Bjergbakke et al. 1981)
1 × 104 s−1 (Quiroga and Perissinotti 2005)
2.50 × 109 L mol−1 s−1 (Klaning and Wolff 1985)
9.00 × 107 L mol−1 s−1 (Bielski 1993)
3 × 108 L mol−1 s−1 (Su et al. 1979)
4.2 × 109 L mol−1 s−1 (Atkinson et al. 2007)
Equilibrium
constant
+
–
3.98 × 108 М
HOCl ⇄ H + ClO (Adam et al. 1992)
Cl2+H2O⇄H++Cl–+HOCl (Wang and Margerum 1994) 1 × 10–3 М2
0.70 М−1
Cl– + OH ⇄ ClOH– (Yu 2004)
7.4 × 106 М−1
ClOH– + H+ ⇄ Cl + H2O (Yu 2004)
1.4 × 105 М−1
Cl + Cl– ⇄ Cl2– (Yu 2004)
Forward reaction rate
constant
1.99 × 103 s−1
22 s−1
4.2 × 109 L mol−1 s−1
2.4 × 1010 L mol−1 s−1
7.8 × 109 L mol−1 s−1
Reverse reaction rate
constant
5.00 × 1010 L mol−1 s−1
2.14 × 104 L2 mol−2 s−1
6.0 × 109 s−1
1.8 × 105 s−1
5.7 × 104 s−1
EFFECT OF ADDITION TO THE REACTION SET (R1 – R17) OF VARIOUS
REACTIONS, AND THE PROCESSES OF HO2 DISAPPEARANCE AND OH
GENERATION, ON THE CALCULATED RATES OF CHLORINE EMISSION AND
CHLORATE FORMATION
Kinetic calculations have been performed with the set of reactions (R1 – R17), with the addition of
some other processes which were expected to increase the calculated rates. Henry’s law constant for
ozone and volumetric mass transfer coefficient were taken to be HO3 = 0.24 and kLa = 0.3 s–1.
Chlorine emission rate, (dnCl2/dt)/Vliq, and chlorate formation rate, (dnClO3−/dt)/Vliq, are expressed in
the units μmol L−1 min−1.
Experimental conditions: concentrations in reaction solution [H+] = 0.8 М, [Cl–] = 1 М, [Na+] = 0.2
М, ozone concentration in initial gases 10.4 g/m3, the number of photons absorbed per unit volume
of reaction solution (4.34 ± 0.06) × 1020 photons L−1 min−1.
Table S2. Effect of addition of some chemical reactions to the reaction set (R1 – R17) on calculated
rates of chlorine emission and chlorate formation.
Reactions
(Experiment)
(R1 - R17)
(R1 – R17) +
a) Cl2– + HO2 → 2Cl– + O2 + H+, k = 3.1 × 109 L mol−1 s−1
(Yu 2004)
(R1 – R17) +
b) HO2 + HO2 → H2O2 + O2, k = 7.7 × 105 L mol−1 s−1 (Elliot
and Bartels 2009);
c) H2O2 → 2OH, k = 2.77 × 10–4 s−1, the photolysis rate
constant was calculated with the formula
k = H2O2,254·NΦ· H2O2,254·ln10/(60·NA), where H2O2,254 = 0.5
is the primary quantum yield (Goldstein et al. 2007; Yu and
Barker 2003), NΦ = (4.34 ± 0.06) × 1020 photons L−1 min−1 is
the rate of UV photons absorption by the reaction solution in
the experiments of this work,  H2O2,254 = 20 L mol–1 cm–1 is the
molar absorptivity and hydrogen peroxide in aqueous solution
(Chu and Anastasio 2005).
(R1 – R17) +
d) HO2 + O3 → OH + 2O2, k = 1.2 × 106 L mol−1 s−1
(Nizkorodov et al. 2000). This is the rate constant in the gas
phase. In aqueous solution k < 1 × 104 L mol−1 s−1 (Sehested et
al. 1984).
(R1 – R17) +
e) Cl– + O(1D) → ClO–, k = 1 × 1010 L mol−1 s−1, diffusioncontrolled rate constant (Caldin 2001)
(dnCl2/dt)/Vliq
47.5
13.5
13.5
(dnClO3−/dt)/Vliq
3.55
2.30
2.30
13.5
2.31
13.5
2.30
14.0
2.28
(R1 – R17) +
f) HO2 + O(1D) → OH + O2, k = 1 × 1010 L mol−1 s−1,
diffusion-controlled rate constant (Caldin 2001)
(R1 – R17) +
g) H2O2 + O(1D) → OH + HO2, k = 1 × 1010 L mol−1 s−1,
diffusion-controlled rate constant (Caldin 2001);
b) HO2 + HO2 → H2O2 + O2, k = 7.7 × 105 L mol−1 s−1 (Elliot
and Bartels 2009);
c) H2O2 → 2OH, k = 2.77 × 10–4 s−1.
(R1 – R17) +
b) HO2 + HO2 → H2O2 + O2, k = 7.7 × 105 L mol−1 s−1 (Elliot
and Bartels 2009);
c) H2O2 → 2OH, k = 2.77 × 10–4 s−1;
d) HO2 + O3 → OH + 2O2, k = 1.2 × 106 L mol−1 s−1
(Nizkorodov et al. 2000);
e) Cl– + O(1D) → ClO–, k = 1 × 1010 L mol−1 s−1, diffusioncontrolled rate constant (Caldin 2001);
f) HO2 + O(1D) → OH + O2, k = 1 × 1010 L mol−1 s−1,
diffusion-controlled rate constant (Caldin 2001)
(R1 – R17) +
h) O3 → O(3P) + O2, k = 1 × 10–5 s−1 (Ignatiev et al. 2008;
Sehested et al. 1991);
i) H2O2 + O(3P) → OH + HO2, k = 1.6 × 109 L mol−1 s−1
(Sauer et al. 1984);
j) HO2 + O(3P) → OH + O2, k = 1.6 × 109 L mol−1 s−1
(assumed value);
k) Cl– + O(3P) → ClO–, k = 1 × 108 L mol−1 s−1 (assumed
value);
b) HO2 + HO2 → H2O2 + O2, k = 7.7 × 105 L mol−1 s−1 (Elliot
and Bartels 2009);
c) H2O2 → 2OH, k = 2.77 × 10–4 s−1.
13.5
2.30
13.5
2.30
14.0
2.30
13.5
2.31
Table S3. Effect of intensity of additional sink of HO2 on calculated rates of chlorine emission and
chlorate formation. Kinetic calculations have been performed with the set of reactions (R1 – R17),
plus a process of HO2 disappearance, HO2 → … .
Rate of HO2 disappearance, mol L–1s–1
(Experiment)
0
10
100
1 × 103
4 × 103
5 × 103
(dnCl2/dt)/Vliq
(dnClO3−/dt)/Vliq
47.5
3.55
13.5
2.30
13.5
2.29
13.6
2.24
14.5
1.77
16.9
0.71
The steady state is not established in the calculations.
Table S4. Effect of intensity of additional source of OH on calculated rates of chlorine emission and
chlorate formation. Kinetic calculations have been performed with the set of reactions (R1 – R17),
plus reactions
b) HO2 + HO2 → H2O2 + O2, k = 7.7 × 105 L mol−1 s−1 (Elliot and Bartels 2009);
c) H2O2 → 2OH, k = 2.77 × 10–4 s−1;
d) HO2 + O3 → OH + 2O2, k = 1.2 × 106 L mol−1 s−1 (Nizkorodov et al. 2000);
l) OH + O3 → HO2 + O2, k = 1.1 × 108 L mol−1 s−1 (Sehested et al. 1984);
m) OH + OH → H2O2, k = 4.64 × 109 (Elliot and Bartels 2009);
n) OH + HO2 → O2 + H2O, k = 8.59 × 109 (Elliot and Bartels 2009);
plus a process of OH generation, … → OH.
Rate of OH generation, mol L–1s–1
(Experiment)
0
1 × 10–9
1 × 10–8
1 × 10–7
1 × 10–6
1 × 10–5
1 × 10–4
1 × 10–3
0.1
1
10
100
1000
(dnCl2/dt)/Vliq
(dnClO3−/dt)/Vliq
47.5
3.55
13.5
2.31
13.5
2.34
13.4
2.60
13.0
5.21
8.5
31.4
–4
2.68 × 10
78.8
8.71 × 10–3
78.8
The steady state is not established in the calculations.
8.09 × 10–3
3.70 × 10–2
2.34 × 10–4
3.63 × 10–3
7.40 × 10–5
3.41 × 10–4
2.34 × 10–5
2.84 × 10–5
7.39 × 10–6
1.75 × 10–6
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