Environmental Engineering Reference
In-Depth Information
M
n
+
+
R
′
O
•
+
H
+
→
M
(
n
+
1
)+
+
R
′
OH
(5.2)
On the other hand, the reduction of Cu(II) and Fe(III) by H
2
O
2
and ROOH
compounds (Moffett and Zika
1987a
; Moffett and Zika
1987
) can be generalized
in the following scheme:
(5.3)
R
′
OOH
⇋
H
+
+
R
′
O
2
R
′
=
H or R
M
(
n
+
1
)+
+
R
′
O
2
→
M
n
+
+
R
′
O
2
•
(5.4)
(5.5)
HO
2
•
⇋
H
+
+
O
2
•−
M
(
n
+
1
)+
+
O
2
•−
→
M
n
+
+
O
2
(5.6)
These reactions have already been verified for various chemical and biochemical
processes in natural waters.
5.5 Medical Treatment and Commercial Uses of H
2
O
2
H
2
O
2
therapy is commonly used in bio-medical sciences. The singlet oxygen
atoms produced from H
2
O
2
in the human body (H
2
O
2
→
H
2
O
+
O
1
) can kill or
severely inhibit the growth of anaerobic organisms (bacteria and viruses that use
carbon dioxide for fuel and leave oxygen as a by-product) (Gorren et al.
1986
).
Bacteria and viruses do not have an enzyme coating, thus they are easily oxidized
by O
1
. Application of H
2
O
2
is particularly effective for asthma, leukemia, multi-
ple sclerosis, degenerative spinal disc disease, high blood pressure and wound care
(Gorren et al.
1986
; Nathan and Cohn
1981
). In addition, H
2
O
2
is widely used to
bleach textiles and paper products, in processing foods, minerals, petrochemicals,
consumer products (detergents), and in some daily uses such as cleaning and sani-
tizing the kitchen, soaking the toothbrush to prevent transfer of germs, cleaning
vegetables and fruits for freshness and good taste.
5.6 Growth of Terrestrial Vegetation by Rainwater's H
2
O
2
and ROOH
High concentrations of H
2
O
2
(0-199000 nM) and ROOH (60-6500 nM) in rain-
water (Table
1
) should be able to promote photosynthesis in plants and algae
(Komissarov
1995
,
2003
; Mostofa et al.
2009a
,
b
). The detailed mechanism in that
regard has been discussed in photosynthesis chapter (see chapter
“
Photosynthesis
