Supporting Information
1. The determining time of Ala reported in references
TABLE S1 The definition of ta expressed in literature
Measurement Conditions
The expression of ta
[Ferron] (M) [AlT] (M)
8.1×10-4
≤1.1×10-4
The color intensity for monomeric Al was read 30 s after mixing.
References
[1]
8.1×10-4
5.7×10-5
The color intensity was read periodically from 20 s after mixing
until a constant intensity was attained. The monomeric Al
concentration was calculated by extrapolating the amount of Al
reacted to time =0.
[2]
1.0×10-3
—
Mononuclear Al distinguished from the others by assuming a 30 s
reaction with ferron.
[3]
2.0×10-3
8.0×10-5
Monomeric aluminum species react practically instantaneously
with ferron, their concentration may be determined by taking
absorbance readings at a short fixed time (30 s) after mixing.
[4]
1.2×10-3
2.4×10-5
Based on the reaction kinetics of acidified (pH~2.3) A1 standards,
Ala was known to completely react within 1.5-3 min.
[5]
≥2×10-3 *
5.3×10-5
Ala was the species reacted with ferron within 1 min. It was the
first point on the A-t curve.
[6]
1.9×10-3
≤1.0×10-4
The Al recovered in 40 s was taken as the concentration of
mononuclear A1 ions.
[7]
1.1×10-3
—
Ala was the species reacted with ferron within 1 min.
[8]
5.6×10-4
—
The timed absorbance measurements (at 366 nm), using a DU650
Beckman UV-Visible spectrophotometer, were carried out after 1
min and recorded for further 2 h. It was operationally divided that
the first 1 min absorbance as Ala.
[9]
—
8.0×10-5
Monomeric species (Ala) reacted with ferron within 1 min.
[9]
5.7×10-4
8.2×10-5
The fractions of Ala were calculated using the absorbance measured
in the initial 30 s of Al-ferron interactions.
[10]
1.2×10-3
2.4×10-5
The absorbance within 1 min was attributed to the monomeric
Al—Ala.
[11]
1
2. The changing trend of Ala% with ta under different [Ferron] for other [AlT] levels
I. [AlT]=2.0×10-3 M
100
100
80
80
80
60
Ala%
100
Ala%
120
60
40
40
20
20
20
0
0
60
90
120
150
0
30
60
90
80
Ala%
100
80
Ala%
100
80
Ala%
100
60
60
40
40
20
20
90
120
150
90
120
30
150
80
Ala%
100
80
Ala%
100
80
Ala%
100
60
40
40
20
20
20
0
0
120
150
60
90
120
30
150
100
80
80
Ala%
100
80
Ala%
100
Ala%
120
60
40
40
20
20
20
0
0
150
60
90
120
30
150
120
100
100
100
80
80
80
Ala%
Ala%
Ala%
120
60
40
40
20
20
20
0
0
90
120
150
60
90
120
30
150
80
Ala%
100
80
Ala%
100
80
Ala%
100
60
40
40
20
20
20
0
0
120
150
60
90
120
30
150
100
80
80
Ala%
100
80
Ala%
100
Ala%
120
60
40
40
20
20
20
0
0
120
150
120
150
120
150
60
40
90
90
ta (s)
120
60
60
ta (s)
120
30
150
0
30
ta (s)
60
120
60
40
90
90
ta (s)
120
60
60
ta (s)
120
30
150
0
30
ta (s)
120
60
120
60
40
60
90
ta (s)
120
30
60
ta (s)
60
150
0
30
ta (s)
(e)
120
60
40
120
90
ta (s)
120
90
60
ta (s)
120
60
150
0
30
ta (s)
60
90
60
40
30
60
ta (s)
120
90
120
0
60
120
60
150
20
30
120
30
120
60
ta (s)
60
90
40
0
60
60
ta (s)
120
ta (s)
(g)
30
120
30
(f)
150
120
0
(d)
120
ta (s)
ta (s)
(c)
60
40
30
(b)
III. [AlT]=8.0×10-3 M
120
Ala%
(a)
II. [AlT]=4.0×10-3 M
120
0
30
60
90
ta (s)
ta (s)
120
150
30
60
90
ta (s)
FIGURE S1 The changing trend of Ala% with ta under different [Ferron] in the HPAS (a. OH/Al=0; b. OH/Al=0.5;
c. OH/Al=1.0; d. OH/Al=1.4; e. OH/Al=1.7; f. OH/Al=2.0; g. OH/Al=2.3. [Ferron]=2.0×10 -4 M (■), 4.0×10-4 M
(○), 8.0×10-4 M (▲), 1.2×10-3 M (▽), 1.6×10-3 M (◆), 2.0×10-3 M (◁), 2.4×10-3 M (★), 3.0×10-3 M (□))
2
3. The changing trend of Ala% with [Ferron] at different ta for the other [AlT] levels
[AlT]=4.0×10-5 M
[AlT]=2.0×10-5 M
120
100
100
100
80
80
80
60
Ala%
120
Ala%
Ala%
(a)
60
40
40
20
20
20
0
0
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
0
-0.5
0.0
0.5
[Ferron] ( ×10 M)
Ala%
Ala%
Ala%
80
60
60
40
40
20
20
20
0
0
1.0
1.5
2.0
2.5
3.0
3.5
0.0
0.5
1.5
2.0
2.5
3.0
3.5
-0.5
100
80
80
Ala%
100
80
60
40
40
20
20
20
0
0
2.0
2.5
3.0
0.0
0.5
1.0
1.5
2.0
2.5
3.0
-0.5
3.5
80
Ala%
100
80
Ala%
100
80
60
40
40
20
20
20
0
0
2.0
2.5
3.0
3.5
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
-0.5
100
80
80
Ala%
100
80
Ala%
100
60
40
40
20
20
20
0
0
2.0
2.5
3.0
3.5
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
-0.5
100
80
80
Ala%
100
80
Ala%
100
60
40
40
20
20
20
0
0
2.0
2.5
3.0
3.5
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
-0.5
100
80
80
Ala%
100
80
Ala%
100
60
40
40
20
20
20
0
0
1.5
2.0
-3
2.5
3.0
3.5
2.0
2.5
3.0
3.5
1.0
1.5
2.0
2.5
3.0
3.5
0.5
1.0
1.5
2.0
2.5
3.0
3.5
2.5
3.0
3.5
60
40
1.0
1.5
-3
120
[Ferron] ( ×10 M)
1.0
[Ferron] ( ×10 M)
120
0.5
0.0
-3
120
0.0
0.5
[Ferron] ( ×10 M)
-3
-0.5
3.5
0
-0.5
[Ferron] ( ×10 M)
60
3.0
60
40
1.5
2.5
-3
120
1.0
2.0
[Ferron] ( ×10 M)
120
0.5
0.0
-3
120
0.0
0.5
[Ferron] ( ×10 M)
-3
-0.5
1.5
0
-0.5
[Ferron] ( ×10 M)
60
1.0
60
40
1.5
3.5
-3
120
1.0
3.0
[Ferron] ( ×10 M)
120
0.5
0.0
-3
120
0.0
0.5
[Ferron] ( ×10 M)
-3
-0.5
2.5
0
-0.5
[Ferron] ( ×10 M)
60
2.0
60
40
1.5
1.5
-3
100
1.0
1.0
[Ferron] ( ×10 M)
120
0.5
0.0
-3
120
0.0
0.5
[Ferron] ( ×10 M)
120
60
3.5
0
-0.5
3.5
3.0
60
40
1.5
2.5
-3
100
1.0
2.0
[Ferron] ( ×10 M)
120
0.5
0.0
-3
Ala%
Ala%
Ala%
1.0
[Ferron] ( ×10 M)
120
0.0
1.5
0
-0.5
120
60
1.0
60
40
0.5
0.5
-3
100
0.0
0.0
[Ferron] ( ×10 M)
80
-0.5
Ala%
-0.5
100
-3
Ala%
3.5
80
[Ferron] ( ×10 M)
Ala%
3.0
100
-0.5
(g)
2.5
120
-3
(f)
2.0
-3
120
[Ferron] ( ×10 M)
(e)
1.5
120
-0.5
(d)
1.0
[Ferron] ( ×10 M)
-3
(c)
60
40
-0.5
(b)
[AlT]=8.0×10-5 M
120
0
-0.5
0.0
0.5
1.0
1.5
2.0
[Ferron] ( ×10 M)
-3
2.5
3.0
3.5
-0.5
0.0
0.5
1.0
1.5
2.0
[Ferron] ( ×10 M)
-3
FIGURE S2 The changing trend of Ala% with [Ferron] at different ta (a. OH/Al=0; b. OH/Al=0.5;
c. OH/Al=1.0; d. OH/Al=1.4; e. OH/Al=1.7; f. OH/Al=2.0; g. OH/Al=2.3. ta=40 s (■), 60 s (○), 80
s (▲), 100 s (▽), 120 s (★), 140 s (＊))
3
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