Toxicity The relative degree of being poisonous or toxic. A condition which may
exist in wastes and will inhibit or destroy the growth or function of certain
organisms.
Trace gas Any one of the less common gases found in the Earth’s atmosphere.
Nitrogen, oxygen, and argon make up more than 99 percent of the Earth’s
atmosphere. Other gases, such as carbon dioxide, water vapor, methane, oxides
of nitrogen, ozone, and ammonia, are considered trace gases. Although relatively
unimportant in terms of their absolute volume, they have significant effects on the
Earth’s weather and climate.
Transpiration Similar to Evapotranspiration.
Tropical storm A severe storm that develops over tropical seas with winds from
39 to 73 miles per hour.
Troposphere The lowest part of the atmosphere from the surface to about 10 km in
altitude in mid-latitudes (ranging from 9 km in high latitudes to 16 km in the
tropics on average) where clouds and “weather” phenomena occur. In the troposphere, temperatures generally decrease with height.
Tsunami Enormous waves caused by underwater disturbances such as
earthquakes.
Tundra A treeless, level, or gently undulating plain characteristic of the Arctic and
sub-Arctic regions characterized by low temperatures and short growing seasons.
Turbid Having a cloudy or muddy appearance.Two-stage DAFA series of two
consecutive dissolved air flotation treatment using different chemicals or operational conditions.
Two-stage treatment A series of two consecutive water or wastewater treatment
using different chemicals, operational conditions, or even different unit
processes.
Ultraviolet radiation (UV) (a) Most UV disinfection units are constructed with an
array of VU lamps installed in a water, wastewater, or air channel, for water
disinfection, wastewater disinfection, or air disinfection, respectively. A proper
dosage of UV radiation has shown to be an effective bactericide and virucide
while not contributing to the formation to toxic disinfection by-products. However, certain compounds may be altered by UV radiation. Because the effective
distance of UV light is very limited, most UV disinfection occurs when the light
penetration depth can be minimized, termed the thin film approach. The term
“thin film” refers to the separation distance between the UV tubes. (b) The energy
range just beyond the violet end of the visible spectrum. Although ultraviolet
radiation constitutes only about 5 percent of the total energy emitted from the sun,
it is the major energy source for the stratosphere and mesosphere, playing a
dominant role in both energy balance and chemical composition. Most ultraviolet
radiation is blocked by Earth’s atmosphere, but some solar ultraviolet penetrates
and aids in plant photosynthesis and helps produce vitamin D in humans. Too
much ultraviolet radiation can burn the skin, cause skin cancer and cataracts, and
damage vegetation.
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M.-H. S. Wang and L. K. Wang
exist in wastes and will inhibit or destroy the growth or function of certain
organisms.
Trace gas Any one of the less common gases found in the Earth’s atmosphere.
Nitrogen, oxygen, and argon make up more than 99 percent of the Earth’s
atmosphere. Other gases, such as carbon dioxide, water vapor, methane, oxides
of nitrogen, ozone, and ammonia, are considered trace gases. Although relatively
unimportant in terms of their absolute volume, they have significant effects on the
Earth’s weather and climate.
Transpiration Similar to Evapotranspiration.
Tropical storm A severe storm that develops over tropical seas with winds from
39 to 73 miles per hour.
Troposphere The lowest part of the atmosphere from the surface to about 10 km in
altitude in mid-latitudes (ranging from 9 km in high latitudes to 16 km in the
tropics on average) where clouds and “weather” phenomena occur. In the troposphere, temperatures generally decrease with height.
Tsunami Enormous waves caused by underwater disturbances such as
earthquakes.
Tundra A treeless, level, or gently undulating plain characteristic of the Arctic and
sub-Arctic regions characterized by low temperatures and short growing seasons.
Turbid Having a cloudy or muddy appearance.Two-stage DAFA series of two
consecutive dissolved air flotation treatment using different chemicals or operational conditions.
Two-stage treatment A series of two consecutive water or wastewater treatment
using different chemicals, operational conditions, or even different unit
processes.
Ultraviolet radiation (UV) (a) Most UV disinfection units are constructed with an
array of VU lamps installed in a water, wastewater, or air channel, for water
disinfection, wastewater disinfection, or air disinfection, respectively. A proper
dosage of UV radiation has shown to be an effective bactericide and virucide
while not contributing to the formation to toxic disinfection by-products. However, certain compounds may be altered by UV radiation. Because the effective
distance of UV light is very limited, most UV disinfection occurs when the light
penetration depth can be minimized, termed the thin film approach. The term
“thin film” refers to the separation distance between the UV tubes. (b) The energy
range just beyond the violet end of the visible spectrum. Although ultraviolet
radiation constitutes only about 5 percent of the total energy emitted from the sun,
it is the major energy source for the stratosphere and mesosphere, playing a
dominant role in both energy balance and chemical composition. Most ultraviolet
radiation is blocked by Earth’s atmosphere, but some solar ultraviolet penetrates
and aids in plant photosynthesis and helps produce vitamin D in humans. Too
much ultraviolet radiation can burn the skin, cause skin cancer and cataracts, and
damage vegetation.
490
M.-H. S. Wang and L. K. Wang