232
K. M. G. Mostofa et al.
Table 3 The reaction rate constants for the production of HO •
in photo-ferrioxalate/H
2 O
2 reaction
Reaction type
Rate constant (k) (M
−1 s
−1 )
Equations
References
Fe III
(C
2 O
4 ) 3−2n
+ hυ
→ Fe 2+
+ (n-1)C
2 O
4
2−
+ C
2 O
4
•−
–
3.19
Jeong and Yoon (2005)
C
2 O
4
•−
→ CO
2
+ CO
2
•−
2
× 10 12
3.20
Mulazzani et al. (1986)
Fe III
(C
2 O
4 )
n
3−2n
+ CO
2
•−
→ CO
2
+ Fe II
(C
2 O
4 )
n
2−2n
≈8 × 10 9
3.21
Jeong and Yoon (2004)
CO
2
•−
+ O
2
→ CO
2
+ O
2
←←•
2.4
× 10 9
3.22
Hislop and Bolton (1999)
Fe III
(C
2 O
4 )
n
3−2n
+ O
2
•−
→ O
2
+ Fe II
(C
2 O
4 )
n
2−2n
<1
× 10 6
3.23
Sedlak and Hoigné (1993)
Fe III
(C
2 O
4 )
n
3−2n
+ HO
2
•
→ O
2
+ Fe II
(C
2 O
4 )
n
2−2n
<1.2
× 10 5
3.24
Sedlak and Hoigné (1993)
Fe II
(C
2 O
4 )
+ H
2 O
2
→ Fe III
(C
2 O
4 )
+
+ HO
•
+ OH
−
3.1
× 10 4
3.25
Sedlak and Hoigné (1993)
Fe 2+
+ HO•
→ Fe III
(OH) 2+
4.3
× 10 8
3.26
Zuo and Hoigné (1992)
Fe III
(OH) 2+
+ hυ
→ Fe 2+
+ HO•
Negligible
3.27
Jeong and Yoon (2005)
Fe 3+
+ O
2
•−
→ Fe 2+
+ O
2
1.5
× 10 8
3.28
Balmer and Sulzberger (1999)
C
2 O
4
2−
+ HO•
→ CO
2
+ CO
2
•−
+ OH
−
7.7
× 10 6
3.29
Buxton et al. (1988)
HC
2 O
4
—
+ HO•
→ CO
2
+ CO
2
•−
+ H
2 O
4.7
× 10 7
3.30
Buxton et al. (1988)
CPAA a
+ HO•
→ products
3.0
× 10 9
3.31
Pignatello (1992)
Equilibrium reactions
Equilibrium constants
(M
−1 )
Fe 3+
+ C
2 O
4
2−
↔ Fe III
(C
2 O
4 )
+
2.5
× 10 9
3.32
Faust and Zepp (1993)
Fe III
(C
2 O
4 )
+
+ C
2 O
4
2−
↔ Fe III
(C
2 O
4 )
2
−
6.3
× 10 6
3.33
Faust and Zepp (1993)
Fe III
(C
2 O
4 )
−
+ C
2 O
4
2−
↔ Fe III
(C
2 O
4 )
3
3−
3.8
× 10 4
3.34
Faust and Zepp (1993)
Fe 2+
+ C
2 O
4
2−
↔ Fe II
(C
2 O
4 )
2.0
× 10 5
3.35
Faust and Zepp (1993)
Fe II
(C
2 O
4 )
+ C
2 O
4
2−
↔ Fe II
(C
2 O
4 )
2
2−
1.2
× 10 2
3.36
Faust and Zepp (1993)
HC
2 O
4
+
↔ C
2 O
4
2−
+ H
+
6.2
× 10 1
3.37
Zuo and Hoigné (1992)
HO
2
•
↔ O
2
•−
+ H
+
6.2
× 10 1
3.38
Bielski et al. (1985)
a
CPAA means the 2,4-dichlorophenoxyacetic acid