Environmental Engineering Reference
In-Depth Information
thirteenth century when King Edward I banned the burning of kiln coal in London due
to its impacts on air quality (Wilson 1996).
Temperature and pressure are two important factors affecting the migration of contami-
nants in the atmosphere. The reason temperature and pressure play a much more signifi-
cant role in atmospheric fate and transport than in soil and water is because of the ideal
gas laws—a combination of Boyle's and Charles' gas laws describing the relationships
between temperature, density, and pressure. Temperature and pressure typically decrease
with increasing altitude in the troposphere. The temperature in the lower portion of the
stratosphere is relatively constant and helped give rise to its name meaning “stratified”
(Figure 8.13). Table 8.1 lists the standard temperatures and atmospheric pressure within
the atmosphere (United States Standard Atmosphere 1976).
The composition of the atmosphere is detailed in Table 8.2 (United States Standard
Atmosphere 1976).
Oxygen is a recent addition to the atmosphere in geological terms. The origin of oxygen
began with algae production approximately 2.45 billion years ago (Farquhar et al. 2000;
Raub and Kirschvink 2008). The presence of oxygen in the atmosphere plays a significant
role and affects contamination in the environment through oxidation reactions and rates
of combustion (USEPA 2008a).
Contaminants initially released into the atmosphere often do not remain in the air; they
settle out and contaminant the soil or surface water. Some contaminants, however, remain
in the atmosphere for long periods of time, and other contaminants initially released
into soil or water may volatilize and contaminate the air. In some cases, air contaminants
may settle out of the atmosphere and adsorb onto a soil grain on the land surface only
TABLE 8.1
Standard Atmospheric Temperature and Pressure
with Increasing Altitude
Altitude
Temperature
ft
m
Pressure (atm)
°F
°C
0
0
1.000
59.0
15.0
2,000
610
0.943
51.9
11.0
4,000
1,219
0.888
44.7
7.0
6,000
1,826
0.836
37.6
3.1
8,000
2,438
0.786
30.5
−0.8
10,000
3,048
0.738
23.3
−5.0
15,000
4,572
0.564
5.5
−14.7
20,000
6,096
0.459
−12
−24.4
30,000
9,144
0.297
−48
−44.4
40,000
13,123
0.185
−67
−55
60,000
18,288
7.1 × 10 −2
−67
−55
80,000
24,384
2.7 × 10 −2
−67
−55
100,000
30,480
1.0 × 10 −2
−67
−55
140,000
42,672
2.0 × 10 −3
74
23.3
180,000
54,864
5.7 × 10 −4
170
76.7
220,000
67,056
1.7 × 10 −4
92
33.3
300,000
91,440
1.5 × 10 −5
27
−2.8
380,000
115,824
7.7 × 10 −7
188
86.7
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