1
Supporting Information for
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Photo-Aging of Polyvinyl Chloride Microplastic in the
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Presence of Natural Organic Acids
4
Chao Wang1, Zeyu Xian1, Xin Jin1, Sijia Liang1, Zhanghao Chen1, Bo Pan2, Bing
Wu1, Yong Sik Ok3, Cheng Gu*1
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State Key Laboratory of Pollution Control and Resource Reuse, School of the
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Environment, Nanjing University, Nanjing 210023, P.R. China
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Faculty of Environmental Science & Engineering, Kunming University of
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Science & Technology, Kunming 650500, P.R. China
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Korea Biochar Research Center, O-Jeong Eco-Resilience Institute (OJERI) &
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Division of Environmental Science and Ecological Engineering, Korea University,
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Seoul 02841, Republic of Korea
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*Corresponding author
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Cheng Gu
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Professor
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Phone/Fax: +86-25-89680636
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E-mail: chenggu@nju.edu.cn
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Number of Pages: 31
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Number of Texts: 5
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Number of Tables: 5
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Number of Figures: 20
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Number of Schemes: 2
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S1
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Text S1
Guaranteed reagent PVC-MP particles with sizes of 2, 10, 25 and 150 µm were
purchased from GuanBu-Tech (Shanghai, China). Analytical-reagent grade sodium
oxalate, sodium citrate, sodium carbonate (Na2CO3), sodium bicarbonate (NaHCO3),
ferric sulfate (Fe2(SO4)3), sodium dihydrogen phosphate (NaH2PO4), sodium phosphate
dibasic (Na2HPO4), nitroblue tetrazolium chloride (NBT) and N,N-diethyl-pphenylenediamine (DPD) were all from Sigma-Aldrich (St. Louis, MO, USA) and used
as received. 5,5-dimethy-1-pyrroline N-oxide (DMPO) was obtained from Dojindo
Laboratories (Kumamoto, Japan) and served as the spin trap for photo-generated free
radicals. Bovine liver catalase (CAT, 4000 units mg-1), peroxidase from horseradish
(>100 units mg-1), superoxide dismutase from erythrocytes (SOD, >3000 units mg-1),
ciprofloxacin and tert-butanol (TBA, 99%) were purchased from J&K Scientific Co.
(Shanghai, China). Milli-Q water (18.2 MΩ cm) was utilized in all the experiments.
Text S2
In the present study, NBT was added into the Fe(III) (i.e., Fe2(SO4)3), LMWOA
(i.e., oxalate and citrate) and LMWOA-Fe(III) (i.e., oxalate-Fe(III) and citrate-Fe(III))
reaction solutions for irradiation with the respective initial concentrations of 10.0 μM,
100.0 μM and 10.0 mM for Fe(III), LMWOA and NBT. The pH of the reaction solution
was maintained at pH 7.0 ± 0.2. Subsequently, the UV-vis spectra were collected after
photo-irradiation at predetermined time intervals. For comparison, the UV-vis spectrum
of the control group containing NBT was also determined.
Text S3
Briefly, 40 µL 100 mM DPD and 40 µL peroxidase (1 g L-1) (from
horseradish, >100 units mg-1) were added into the 40 mL reaction solution containing
LMWOA or LMWOA-Fe(III) prior to photo-treatment. After irradiation for a specific
time interval, a great absorbance at 551 nm was obtained due to the production of
oxidative product of DPD by the reaction of peroxidase and photo-generated H2O2.
Then, the concentration of H2O2 was determined by UV-vis spectrophotometer (Varian
Cary 50, Varian Palo Alto, CA, USA) using molar absorption coefficient of 21,000 M1
cm-1 at 551 nm.
Text S4
The surface morphologies of PVC-MP before and after photo-treatments under
ambient conditions were investigated using an environmental scanning electron
microscopy (SEM, FEG Quanta 250, FEI Co., Netherland). Prior to image collection,
a layer of gold was sputtered to coat the PVC-MP sample surface by a TED PELLA,
108 Auto Sputter Coater. Moreover, the Brunauer-Emmett-Teller (BET) surface areas
of pristine and aged PVC-MP particles were measured by nitrogen-flow adsorptiondesorption on a Micrometrics ASAP2020 analyzer at -196 oC. In order to assess the
surface hydrophilicity of PVC-MP, the goniometer (Rame-Hart 250, Succasumna, NJ,
USA) and DROPImage Advanced software (Rame-Hart, Succasumna, NJ, USA) were
used to determine and calculate the contact angles for water (θW) according to the drop
contact angle method. A minimum of ten repeated measurements were performed for
S2
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84
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θW at different positions of each sample in triplicate at room temperature.
Text S5
For each experiment, 10.0 mg photo-aged PVC-MP was added into a 15 mL glass
centrifuge tube containing 10.0 mL CIP solution with the initial concentrations in the
range of 0.5-50.0 mg L-1. The solution pH was maintained at 7.0 ± 0.2 using 1.0 mM
phosphate buffer. The centrifuge tubes were capped and shaken on a rotary shaker (200
rpm, IS-RDV1, Crystal, USA) at 25 ºC for 48 h in the dark, and then centrifuged at
1,000 g for 60 min. No significant loss due to transformation and adsorption onto the
cap during the adsorption process was observed as indicated by >98.9% recovery in the
control experiment. The CIP concentration in supernatant was then determined using a
high pressure liquid chromatography (HPLC) (Water Alliance 2695, Milford, MA)
equipped with an Agilent C18 reverse phase column (5 µm, 4.6 × 150 mm) monitored
at 277 nm by a Waters Alliance 2998 photodiode array detector. A mixture of
acetonitrile and 50 mM citric acid (15/85, v/v) adjusted to pH 3.5 by triethylamine was
used as the mobile phase and the flow rate was set as 1.0 mL min-1. For comparison,
the adsorption of CIP was also determined for pristine PVC-MP.
S3
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Table S1. Fitted zero-order dechlorination rate constants of PVC-MP under ambient
condition.
PVC
PVC+Fe(III)
PVC+Oxalate
PVC+Citrate
PVC+Oxalate-Fe(III)
PVC+Citrate-Fe(III)
2 µm
20.46 ± 1.42
16.25 ± 0.45
21.88 ± 1.85
19.45 ± 1.62
29.20 ± 2.17
25.97 ± 1.89
R2
0.98
0.99
0.96
0.96
0.97
0.97
Zero-order Dechlorination Rate Constants
kobs × 102 (µM h-1)
10 µm
R2
25 µm
R2
13.98 ± 0.85 0.98 12.79 ± 1.20 0.96
12.29 ± 0.33 0.99 11.66 ± 0.52 0.99
18.17 ± 0.62 0.99 18.02 ± 0.95 0.98
15.17 ± 1.09 0.97 14.98 ± 0.60 0.99
23.86 ± 1.24 0.99 23.60 ± 0.75 0.99
21.23 ± 1.04 0.99 19.85 ± 0.61 0.99
93
S4
150 µm
7.94 ± 0.38
7.71 ± 0.73
10.98 ± 0.67
8.21 ± 0.47
14.32 ± 0.96
11.84 ± 0.64
R2
0.99
0.96
0.98
0.98
0.98
0.98
94
95
96
Table S2. Fitted zero-order dechlorination rate constants of PVC-MP under anaerobic
condition.
PVC
PVC+Fe(III)
PVC+Oxalate
PVC+Citrate
PVC+Oxalate-Fe(III)
PVC+Citrate-Fe(III)
2 µm
15.82 ± 0.41
13.89 ± 0.54
9.11 ± 0.59
12.45 ± 1.54
5.90 ± 0.15
8.41 ± 0.50
R2
0.99
0.99
0.97
0.96
0.97
0.98
Zero-order Dechlorination Rate Constants
kobs × 102 (µM h-1)
10 µm
R2
25 µm
R2
10.45 ± 0.30 0.99
7.93 ± 0.26
0.99
11.42 ± 0.21 0.99
6.97 ± 0.31
0.99
7.97 ± 0.28 0.99
4.56 ± 0.26
0.97
8.80 ± 0.25 0.97
6.20 ± 0.70
0.94
5.40 ± 0.36 0.97
2.95 ± 0.15
0.99
7.03 ± 0.31 0.99
4.24 ± 0.33
0.97
97
S5
150 µm
5.24 ± 0.17
5.73 ± 0.16
3.99 ± 0.12
4.41 ± 0.14
2.71 ± 0.18
3.53 ± 0.22
R2
0.99
0.98
0.98
0.99
0.97
0.98
98
99
100
Table S3. Fitted zero-order dechlorination rate constants of PVC-MP under high oxic
condition.
PVC
PVC+Fe(III)
PVC+Oxalate
PVC+Citrate
PVC+Oxalate-Fe(III)
PVC+Citrate-Fe(III)
2 µm
20.43 ± 1.19
17.21 ± 0.52
25.13 ± 2.27
22.35 ± 1.99
32.22 ± 2.62
28.67 ± 2.30
R2
0.98
0.99
0.96
0.96
0.96
0.97
Zero-order Dechlorination Rate Constants
kobs × 102 (µM h-1)
10 µm
R2
25 µm
R2
14.02 ± 0.90 0.98 12.91 ± 1.48 0.94
13.00 ± 0.26 0.99 12.37 ± 0.68 0.99
20.83 ± 0.75 0.99 20.62 ± 0.85 0.99
17.39 ± 1.27 0.97 17.15 ± 0.56 0.99
26.27 ± 1.37 0.98 25.99 ± 0.79 0.99
23.37 ± 1.14 0.99 21.84 ± 0.46 0.99
101
S6
150 µm
7.99 ± 0.53
8.19 ± 0.87
12.72 ± 0.74
9.40 ± 0.47
15.57 ± 0.90
13.02 ± 0.62
R2
0.98
0.94
0.98
0.99
0.98
0.99
102
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Table S4. BET surface area of pristine and photo-aged PVC-MP particles.
BET surface area (m2 g-1)
2 µm
10 µm
25 µm
150 µm
Pristine PVC
67.75
12.71
5.14
0.81
PVC
70.25
13.29
5.58
0.85
PVC+Fe(III)
69.92
12.97
5.39
0.83
PVC+Oxalate
74.27
13.91
5.7
0.88
PVC+OxalateFe(III)
81.87
15.35
6.36
0.97
PVC+Citrate
72.05
13.62
5.75
0.87
PVC+CitrateFe(III)
77.44
14.56
6.05
0.92
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S7
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111
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Table S5. Fitted Langmuir isotherm parameters for CIP adsorption on pristine and
photo-aged PVC-MPs.
Kd (L mg-1)
Qmax (mg g-1)
R2
Pristine PVC
0.16 ± 0.03
6.65 ± 0.40
0.97
Aged PVC
0.11 ± 0.01
7.51 ± 0.31
0.99
PVC+Fe(III)
0.15 ± 0.02
7.53 ± 0.39
0.98
PVC+Oxalate
0.09 ± 0.02
9.78 ± 0.58
0.98
PVC+Citrate
0.13 ± 0.01
8.02 ± 0.23
0.99
PVC+Oxalate0.13 ± 0.02
10.87 ± 0.54
0.98
Fe(III)
PVC+Citrate0.11 ± 0.02
10.18 ± 0.68
0.97
Fe(III)
The adsorption data was fitted with a linear isotherm model: Qe = (Kd × Ce× Qmax)/(1 +
Kd × Ce), where Kd, Ce, Qe and Qmax refer to the adsorption coefficients (L mg-1), the
equilibrium concentration (mg L-1), the equilibrium adsorption amount (mg g-1) and the
maximum adsorption amount (mg g-1), respectively. R2 is the coefficient of
determination calculated by overall regression analysis.
S8
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25
20
15
10
5
0
0
20
60
80
10 m
PVC
PVC+Fe(III)
PVC+Citrate
PVC+Citralate-Fe(III)
20
15
10
5
0
100
0
20
20
Concentration
of Released Cl- (M)
15
(d)
25 m
PVC
PVC+Fe(III)
PVC+Citrate
PVC+Citrate-Fe(III)
5
0
40
12
60
60
80
100
80
100
150 m
PVC
PVC+Fe(III)
PVC+Citrate
PVC+Citrate-Fe(III)
10
10
20
40
Time (h)
Concentration
of Released Cl- (M)
(c)
0
117
118
119
120
121
40
25
Time (h)
115
116
(b)
2 m
PVC
PVC+Fe(III)
PVC+Citrate
PVC+Citrate-Fe(III)
30
Concentration
of Released Cl- (M)
Concentration
of Released Cl- (M)
(a)
80
100
8
6
4
2
0
0
Time (h)
20
40
60
Time (h)
Figure S1. Photo-dechlorination kinetics of PVC-MP with sizes of 2 (a), 10 (b), 25 (c)
and 150 µm (d) in the presence of citrate and citrate-Fe(III). Reaction conditions: 100
mg L-1 PVC-MP, 100 µM sodium citrate, 5 µM Fe2(SO4)3, 1 mM phosphate buffer (pH
7 ± 0.2) , 500 W xenon light source.
S9
Concentrations of generated H2O2 (M)
122
8
Oxalate
Citrate
Oxalate-Fe(III)
Citrate-Fe(III)
6
4
2
0
0
123
124
125
126
127
20
40
60
Time (h)
80
100
Figure S2. The concentrations of H2O2 generated during the photo-irradiation of
LMWOA and LMWOA-Fe(III). Reaction conditions: 100 µM oxalate/citrate, 10 µM
Fe(III), 100 µM DPD, 1 mg L-1 peroxidase, 1 mM phosphate buffer (pH 7 ± 0.2).
S10
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20
15
10
5
0
0
129
130
131
132
133
134
135
(b) 20
PVC
PVC+Fe(III)
PVC+Oxalate
PVC+Oxalate-Fe(III)
Concentration of Released Cl- (M)
Concentration of Released Cl- (M)
(a) 25
20
40
60
80
100
15
PVC
PVC+Fe(III)
PVC+Citrate
PVC+Citrate-Fe(III)
10
5
0
0
Time (h)
20
40
60
80
100
Time (h)
Figure S3. Photo-dechlorination kinetics of PVC-MP in the presence of 5 µM oxalic
acid (a) and citric acid (b). Reaction conditions: 100 mg L-1 25 µm PVC-MP, 5 µM
sodium oxalate/citrate, 5 µM Fe2(SO4)3, 1 mM phosphate buffer (pH 7 ± 0.2), 500 W
xenon light source.
S11
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25
20
15
10
5
0
0
137
138
139
140
141
142
(b) 25
PVC
PVC+Fe(III)
PVC+Oxalate
PVC+Oxalate-Fe(III)
Concentration of Released Cl- (M)
Concentration of Released Cl- (M)
(a) 30
20
40
60
80
100
20
15
PVC
PVC+Fe(III)
PVC+Citrate
PVC+Citrate-Fe(III)
Linear Fit of Sheet1 H
Linear Fit of Sheet1 F
10
5
0
0
Time (h)
20
40
60
80
100
Time (h)
Figure S4. Photo-dechlorination kinetics of PVC-MP in the presence of 2000 µM
oxalic acid (a) and citric acid (b). Reaction conditions: 100 mg L-1 25 µm PVC-MP,
2000 µM sodium oxalate, 5 µM Fe2(SO4)3, 1 mM phosphate buffer (pH 7 ± 0.2), 500
W xenon light source.
S12
35
60
Average Temperature (oC)
Average Light Intensity (mW cm-2)
143
50
40
30
20
10
0
25
20
15
10
5
0
0
144
145
146
147
148
30
5
10
15
20
25
30
0
Time (d)
(a)
5
10
15
20
25
30
Time (d)
(b)
Figure S5. Weather information during sunlight irradiation period: (a) average light
intensity and (b) average temperature. Sunlight exposure experiments were conducted
from May 1 to May 28, 2020.
S13
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25
PVC
PVC+Fe(III)
PVC+Oxalate
PVC+Oxalate-Fe(III)
20
15
10
5
0
0
7
21
15
PVC
PVC+Fe(III)
PVC+Oxalate
PVC+Oxalate-Fe(III)
10
5
0
0
7
(d) 15
25 m
5
0
7
14
14
21
28
21
28
Time (d)
10
0
10 m
15
28
Concentration of Released Cl- (M)
Concentration of Released Cl- (M)
(c) 20
152
153
154
155
156
14
20
PVC
PVC+Fe(III)
PVC+Oxalate
PVC+Oxalate-Fe(III)
Time (d)
150
151
(b) 25
2 m
Concentration of Released Cl- (M)
Concentration of Released Cl- (M)
(a) 30
21
28
PVC
PVC+Fe(III)
PVC+Oxalate
PVC+Oxalate-Fe(III)
10
5
0
0
Time (d)
150 m
7
14
Time (d)
Figure S6. Photo-dechlorination kinetics of PVC-MP of different sizes in the presence
of Fe(III), oxalate and oxalate-Fe(III) under natural solar irradiation. Reaction
conditions: 100 mg L-1 PVC-MP, 100 µM sodium oxalate, 5 µM Fe2(SO4)3 and 1 mM
phosphate buffer (pH 7 ± 0.2).
S14
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158
20
PVC
PVC+Fe(III)
PVC+Citrate
PVC+Citrate-Fe(III)
15
10
5
0
0
14
21
10
5
0
28
0
7
15
PVC
PVC+Fe(III)
PVC+Citrate
PVC+Citrate-Fe(III)
(d) 15
25 m
10
5
0
7
14
14
21
28
21
28
Time (d)
Concentration of Released Cl- (M)
(c)
0
160
161
162
163
164
165
7
15
10 m
PVC
PVC+Fe(III)
PVC+Citrate
PVC+Citralate-Fe(III)
Time (d)
Concentration of Released Cl- (M)
159
(b) 20
2 m
Concentration of Released Cl- (M)
Concentration of Released Cl- (M)
(a) 25
21
28
PVC
PVC+Fe(III)
PVC+Citrate
PVC+Citrate-Fe(III)
10
5
0
0
Time (d)
150 m
7
14
Time (d)
Figure S7. Photo-dechlorination kinetics of PVC-MP of different sizes in the presence
of Fe(III), citrate and citrate-Fe(III) under natural solar irradiation. Reaction conditions:
100 mg L-1 PVC-MP, 100 µM sodium citrate, 5 µM Fe2(SO4)3 and 1 mM phosphate
buffer (pH 7 ± 0.2).
S15
166
167
14
12
10
8
6
4
2
0
0
40
60
80
10
8
6
4
2
0
100
0
20
40
8
(d)
25 m
PVC
PVC+Fe(III)
PVC+Oxalate
PVC+Oxalate-Fe(III)
6
4
2
0
20
40
60
60
80
100
80
100
Time (h)
Concentration of Released Cl- (M)
(c)
0
169
170
171
172
173
174
20
10 m
PVC
PVC+Fe(III)
PVC+Oxalate
PVC+Oxalate-Fe(III)
12
Time (h)
Concentration of Released Cl- (M)
168
(b)
2 m
PVC
PVC+Fe(III)
PVC+Oxalate
PVC+Oxalate-Fe(III)
16
Concentration of Released Cl- (M)
Concentration of Released Cl- (M)
(a)
80
6
PVC
PVC+Fe(III)
PVC+Oxalate
PVC+Oxalate-Fe(III)
150 m
4
2
0
100
0
Time (h)
20
40
60
Time (h)
Figure S8. Photo-dechlorination kinetics of PVC-MP with sizes of 2 (a), 10 (b), 25 (c)
and 150 µm (d) in the presence of oxalate and oxalate-Fe(III) under anaerobic condition.
Reaction conditions: 100 mg L-1 PVC-MP, 100 µM sodium oxalate, 5 µM Fe2(SO4)3,
1 mM phosphate buffer (pH 7 ± 0.2), 500 W xenon light source.
S16
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14
12
10
8
6
4
2
0
0
40
60
80
10
8
6
4
2
0
100
0
20
8
(d)
25 m
PVC
PVC+Fe(III)
PVC+Citrate
PVC+Citrate-Fe(III)
6
4
2
0
20
40
60
40
60
80
100
80
100
Time (h)
Concentration of Released Cl- (M)
(c)
0
177
178
179
180
181
182
20
10 m
PVC
PVC+Fe(III)
PVC+Citrate
PVC+Citrate-Fe(III)
12
Time (h)
Concentration of Released Cl- (M)
176
(b)
2 m
PVC
PVC+Fe(III)
PVC+Citrate
PVC+Citrate-Fe(III)
16
Concentration of Released Cl- (M)
Concentration of Released Cl- (M)
(a)
80
6
PVC
PVC+Fe(III)
PVC+Citrate
PVC+Citrate-Fe(III)
150 m
4
2
0
100
0
Time (h)
20
40
60
Time (h)
Figure S9. Photo-dechlorination kinetics of PVC-MP with sizes of 2 (a), 10 (b), 25 (c)
and 150 µm (d) in the presence of citrate and citrate-Fe(III) under anaerobic condition.
Reaction conditions: 100 mg L-1 PVC-MP, 100 µM sodium citrate, 5 µM Fe2(SO4)3, 1
mM phosphate buffer (pH 7 ± 0.2), 500 W xenon light source.
S17
183
35
30
PVC
PVC+Fe(III)
PVC+Oxalate
PVC+Oxalate-Fe(III)
25
20
15
10
5
0
0
40
60
80
25
PVC
PVC+Fe(III)
PVC+Oxalate
PVC+Oxalate-Fe(III)
15
10
5
0
0
20
(d) 20
25 m
15
10
5
0
40
60
40
60
80
100
80
100
Time (h)
20
20
10 m
20
100
Concentration of Released Cl- (M)
(c) 30
0
185
186
187
188
189
190
20
25
PVC
PVC+Fe(III)
PVC+Oxalate
PVC+Oxalate-Fe(III)
Time (h)
Concentration of Released Cl- (M)
184
(b) 30
2 m
Concentration of Released Cl- (M)
Concentration of Released Cl- (M)
(a) 40
80
15
PVC
PVC+Fe(III)
PVC+Oxalate
PVC+Oxalate-Fe(III)
150 m
10
100
5
0
0
Time (h)
20
40
60
Time (h)
Figure S10. Photo-dechlorination kinetics of PVC-MP with sizes of 2 (a), 10 (b), 25
(c) and 150 µm (d) in the presence of oxalate and oxalate-Fe(III) after aeration of
oxygen. Reaction conditions: 100 mg L-1 PVC-MP, 100 µM sodium oxalate, 5 µM
Fe2(SO4)3, 1 mM phosphate buffer (pH 7 ± 0.2), 500 W xenon light source.
S18
191
30
PVC
PVC+Fe(III)
PVC+Citrate
PVC+Citrate-Fe(III)
25
20
15
10
5
0
0
40
60
80
20
15
10
5
0
100
0
20
20
PVC
PVC+Fe(III)
PVC+Citrate
PVC+Citrate-Fe(III)
(d)
25 m
15
10
5
0
20
40
60
40
60
80
100
80
100
Time (h)
Concentration of Released Cl- (M)
(c)
0
193
194
195
196
197
198
20
25
10 m
PVC
PVC+Fe(III)
PVC+Citrate
PVC+Citralate-Fe(III)
Time (h)
Concentration of Released Cl- (M)
192
(b) 30
2 m
Concentration of Released Cl- (M)
Concentration of Released Cl- (M)
(a) 35
80
12
10
100
PVC
PVC+Fe(III)
PVC+Citrate
PVC+Citrate-Fe(III)
8
6
4
2
0
0
Time (h)
150 m
20
40
60
Time (h)
Figure S11. Photo-dechlorination kinetics of PVC-MP with sizes of 2 (a), 10 (b), 25
(c) and 150 µm (d) in the presence of citrate and citrate-Fe(III) after aeration of oxygen.
Reaction conditions: 100 mg L-1 PVC-MP, 100 µM sodium citrate, 5 µM Fe2(SO4)3, 1
mM phosphate buffer (pH 7 ± 0.2), 500 W xenon light source.
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199
200
201
202
203
204
205
206
207
208
Figure S12. Time-dependent UV-vis spectra of NBT (a), NBT+Fe(III) (b),
NBT+oxalate (c), NBT+oxalate-Fe(III) (d), NBT+citrate (e), and NBT+citrate-Fe(III)
(f). Reaction conditions: the initial concentrations of NBT, Fe(III), oxalate and citrate
were 10 mM, 10 μM, 100 μM and 100 μM, respectively. 1 mM phosphate was used to
maintain pH 7.0. 500 W xenon lamp was served as the light source.
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210
211
212
213
214
215
216
217
Figure S13. Time-dependent UV-vis spectra of NBT+oxalate+SOD (a), NBT+oxalateFe(III)+SOD (b), NBT+citrate+SOD (c), and NBT+citrate-Fe(III)+SOD (d). Reaction
conditions: the initial concentrations of NBT, Fe(III), oxalate and citrate were 10 mM,
10 μM, 100 μM and 100 μM, respectively. 1 mM phosphate was used to maintain pH
7.0. 500 W xenon lamp was served as the light source.
S21
Concentration of Released Cl- (M)
218
16
12
PVC
PVC+Fe(III)
PVC+Oxalate+TBA
PVC+Citrate+TBA
PVC+Oxalate-Fe(III)+TBA
PVC+Citrate-Fe(III)+TBA
8
4
0
0
20
60
80
100
80
100
Time (h)
(a)
Concentration of Released Cl- (M)
219
16
12
PVC
PVC+Fe(III)
PVC+Oxalate+SOD
PVC+Citrate+SOD
PVC+Oxalate-Fe(III)+SOD
PVC+Citrate-Fe(III)+SOD
8
4
0
0
220
221
40
20
40
60
Time (h)
(b)
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Concentration of Released Cl- (M)
16
12
PVC
PVC+Fe(III)
PVC+Oxalate+CAT
PVC+Citrate+CAT
PVC+Oxalate-Fe(III)+CAT
PVC+Citrate-Fe(III)+CAT
8
4
0
0
222
223
224
225
226
20
40
60
80
100
Time (h)
(c)
Figure S14. PVC-MP dechlorination kinetics in the presence of TBA (a), SOD (b) and
CAT (c). Reaction conditions: 100 mg L-1 25 μm PVC-MP, 100 µM oxalate/citrate, 5
µM Fe2(SO4)3, 1 mM phosphate buffer (pH 7 ± 0.2), 500 W xenon light source.
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228
229
230
231
232
Figure S15. FT-IRIS images of -C=C-, -C=O and -OH groups for PVC-MPs after
natural sunlight irradiation. The aging time is 28 d. PVC-MP with particle size of 150
μm was used for collection of FT-IRIS images.
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233
2912
(a)697
635
1113
2912
(b)
1436
697
635
1520
1113
1436
1520
48 h
48 h
24 h
24 h
12 h
12 h
6h
6h
0h
600
234
800
1000
1200
1400
0h
2800 3200 3600 4000 600
800
1000
697
635
1113
1436
1522
1400
2800
3200
3600
4000
Raman Shift (cm-1)
Raman Shift (cm-1)
(c)
1200
2912
48 h
2912
(d)
697
635
1113
1436
1522
48 h
48 h
24 h
24 h
12 h
12 h
6h
6h
0h
600
235
800
1000
1200
0h
2800 3200 3600 4000 600
800
1000
Raman Shift (cm-1)
(e)
1113
600
800
1000
1200
1400
1400
(f)
1436
2800
3200
3600
4000
2912
697
1515
635
1200
Raman Shift (cm-1)
2912
697
236
237
238
239
240
241
1400
1113
1436
1515
635
48 h
48 h
24 h
24 h
12 h
12 h
6h
6h
0h
0h
2800 3200 3600 4000 600
Raman Shift (cm-1)
800
1000
1200
1400
2800 3200 3600 4000
Raman Shift (cm-1)
Figure S16. In-situ single-particle Raman spectra of PVC-MPs. (a)-(f) refer to the insitu Raman spectra for PVC, PVC+Fe(III), PVC+oxalate, PVC+citrate, PVC+oxalateFe(III) and PVC+citrate-Fe(III), respectively. PVC-MP of 150 μm diameter was used
to collect Raman spectra.
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242
243
244
245
246
247
248
Figure S17. Digital droplet image of PVC-MP before and after photo-irradiation. (a)(g) represent pristine PVC-MP, photo-aged PVC-MP, photo-aged PVC-MP in the
presence of Fe(III), oxalate, citrate, oxalate-Fe(III) and citrate-Fe(III), respectively. 150
µm PVC-MP was used to collect the digital images.
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249
250
251
252
253
254
Figure S18. Optimized structures of PVC aged products involved with hydroxyl radical.
HOMO and LUMO orbitals were calculated to visualize the distribution of electron
cloud and the lengths of C-Cl bonds were labeled next to Cl atoms.
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255
256
257
258
259
260
261
Figure S19. SEM images of PVC-MP surfaces before and after photo-irradiation. (a)(g) represent pristine PVC-MP, photo-aged PVC-MP, photo-aged PVC-MP in the
presence of Fe(III), oxalate, citrate, oxalate-Fe(III) and citrate-Fe(III), respectively. 150
µm PVC-MP was used to collect the SEM images.
S28
262
Equilibrium Adsorption
Amount (Qe, mg g-1)
12
10
8
6
Pristine PVC
Aged PVC
PVC+Fe(III)
PVC+Oxalate
PVC+Citrate
PVC+Oxalate-Fe(III)
PVC+Citrate-Fe(III)
4
2
0
0
263
264
265
266
267
268
269
10
20
30
40
50
Equilibrium Concentration (Ce, mg L-1)
Figure S20. Adsorption isotherms of CIP on pristine and photo-aged PVC-MPs. Qe is
the amount of CIP adsorbed on pristine and light-treated PVC-MPs (mg g-1), and Ce is
the equilibrium concentration of CIP (mg L-1). Experimental conditions: 10 mg 2 μm
PVC-MP, CIP with initial concentrations ranging from 0.5 to 50.0 mg L-1, 10.0 mL
reaction medium (1.0 mM phosphate buffer, pH = 7.0 ± 0.2).
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271
272
Scheme S1. Schematic diagram of in-situ Micro-ATR/FTIR device.
273
S30
274
275
276
Scheme S2. Schematic diagram of in situ ITR-Raman spectroscopy.
S31