Chemistry Reference
In-Depth Information
TABLE 3.5. Second-Order Rate Constants for the Reduction of Chloramines and
Amides by Hydrate Electron and Superoxide
k
(/M/s)
k
(/M/s)
Substrate
e
a
−
O
•−
6.5 × 10
9
glyCl
β-AlaCl
6.1 × 10
9
(gly)
2
Cl
1.5 × 10
10
No reaction
a
(gly)
2
Br
>1 × 10
10
(Ala)
2
Cl
1.4 × 10
10
N
-Chlorosuccinimide
1.6 × 10
10
8.0 × 10
5
6-Aminohexanoic acid chloramines, CANCl
9.3 × 10
9
No reaction
b
1.2 × 10
10
No reaction
c
6-Aminohexanoic acid bromoamines, CANBr
>1 × 10
10
>3.0 × 10
6
N
-Bromoglutarimide
N
-Bromo-4-hydroxy-2-pyrrolidinone, NBr-HOP
6.4 × 10
9
No reaction
d
a
[(gly)
2
Cl] = 170 μM.
b
[CANCl] = 265 μM.
c
[CANBr] = 90 μM.
d
[NBr-HOP] = 60 μM.
Data were taken from References 124 and 125.
O
RR
′
N
•
+
X
-
R = H, alkyl, C —
R
′
= H, alkyl
X = Cl, Br
e
-
aq
/O
2
•-
R
N
X
OR
R
′
O
e
-
aq
/O
2
•-
R = R
′
= C —
X = Br
RR
′
N
-
+
X
•
Figure 3.12.
One-electron reduction of
N
-chlorinated and
N
-brominated species
(adapted from Pattison et al. [125] with the permission of the American Chemical
Society). See color insert.
The rate constants for the oxidation of ferric HRP by ClO
2
and HOCl were
2.7 × 10
4
/M/s and 2.4 × 10
4
/M/s, respectively.
ClO
2
is employed as an alternative to chlorine in the purification and dis-
infection of drinking water, bleaching of paper, sterilization of medical devices,
and sanitization of food products [127-133]. The main advantage of using ClO
2
over chlorine is it controls the formation of harmful organochloro compounds.
Table 3.6 shows the susceptibility of ClO
2
gas for several microorganisms [133].
The mean reduction of gram-negative bacteria and gram-positive bacteria
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