Environmental Engineering Reference
In-Depth Information
usually less than 10% [5] . Ozone is a strong oxide and has an electrode potential of
2.07 V. With the electrode potentials of several strong oxides listed in Table 2.2, it
can be seen that only F 2 with a potential of 2.78 V exceeds that of ozone. Ozone
can react with organic matters in three ways of (i) normal chemical reactions, (ii)
peroxide production, and (iii) decomposition. For example, the reaction of ozone
with toxic xylene produces non-toxic carbon dioxide and water. The interaction of
ozone with polar organic substances causes breakage of the double bonds [6] .
Ta b l e 2. 2 Electrode potentials of common oxides
Name
Formula
Standard electrode potentials (V)
Fluorine
F 2
2.87
Ozone
O 3
2.07
Peroxide
H 2 O 2
1.78
MnO 4 -
Potassium permanganate
1.67
Chloride dioxide
ClO 2
1.50
Chlorine
Cl 2
1.36
Oxygen
O 2
1.23
Given its strong oxidizing property, ozone can be utilized in environmental
engineering to sterilize water and to eliminate water contaminants. Oxygen is the
only residue of ozone decomposition. Thus, oxygen is widely used in hospital and
water treatment [7-10] . However, the unsteady chemical composition of ozone
brings challenges to its storage and transportation.
2.3 Ozone Generation Methods
Jet bombardment, such as electron, nuclear, plasma, and ultraviolet radiation,
decomposes oxygen into oxygen atom. This type of oxygen atom combines with
oxygen molecule to form the triatomic ozone. Stratospheric ozone may be created
by the UV radiation action. The detailed process involving the creation of
stratospheric ozone is given as follows:
O 2 + h =O+O (2.6)
O+O 2 = O 3 (2.7)
O 3 + h =O 2 +O (2.8)
O+O 3 = 2 O 2 (2.9)
Several methods could be employed to generate ozone, including corona
discharge, nuclear radiation, UV radiation, electrolysis, and so on. The industrial
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