Thermal Pollution
Introduced| English | Meaning |
|---|---|
| heat/hiːt/ | Energy transferred between systems because of a temperature difference. |
| thermal pollution/ˈθɜːml pəˈluːʃn/ | heat released into water, usually from power-plant cooling, that harms aquatic organisms |
| cooling/ˈkuːlɪŋ/ | cooling |
| discharged/dɪsˈtʃɑːdʒd/ | discharged |
| oxygen/ˈɒksɪdʒn/ | The gaseous element whose usual molecules contain two atoms and which supports combustion. |
Pollution that is just heat
- Not all pollution is a chemical or a particle.
- Sometimes the pollutant is simply heat 热量.
- Warming a river's water can harm the life in it.
- This is thermal pollution 热污染.
Where the heat comes from
- Power plants draw in cool river water for cooling 冷却.
- The water carries heat away from the machinery.
- Then the warm water is discharged 排放 back into the river.
- Factories do the same, returning warmed water.
Warmer water holds less dissolved oxygen 氧气
Thermal pollution is…
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Thermal pollution is heat added to water — usually warm water discharged by power plants or factories.
Warm water holds less oxygen
- Cold water can hold plenty of dissolved oxygen.
- Warm water holds much less of it.
- So heating the river lowers the oxygen fish depend on.
- The warmer the water, the less oxygen it carries.
How thermal pollution harms a river
Follow cooling water from a power plant to fish struggling in warm, low-oxygen water.
Warmer water is harmful to fish mainly because it…
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Hot water holds less oxygen, so fish struggle to breathe even as their bodies need more.
The most common source of thermal pollution is warm water from power ____.
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Power plants use river water to cool their machinery, then return it warm.
A double hit for fish
- Warmth speeds up a fish's body, so it needs more oxygen.
- But the warm water supplies less oxygen.
- Fish are stressed, and sensitive species may die.
- The whole balance of the river community shifts.
Warm water holds more dissolved oxygen, so fish can breathe more easily.
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False. Warm water holds less dissolved oxygen, while warmth raises fish metabolism and oxygen demand: a double hit.
Select all true statements about thermal pollution.
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Thermal pollution is about heat, not chemicals — warm water holds less oxygen and stresses fish.
Thermal pollution is sneaky because you add nothing to the water — no chemical, no particle, just heat. Yet it's a double blow: warm water holds less oxygen at the very moment it speeds up the fish's need for oxygen. Cold-water species like trout are hit first. It's a reminder that "pollution" includes changing a physical condition, not only adding a substance.
A river below a power plant:
- The plant draws in cool water, uses it for cooling, and discharges it several degrees warmer.
- Just downstream, the warm water carries less oxygen — while the heat makes the fish breathe faster and need more.
- The trout, which need cold, oxygen-rich water, vanish from that stretch, replaced by a few heat-tolerant species.
Thermal pollution is harmful heating of water, usually warm water discharged by power plants and factories after cooling their machinery. Warm water holds less dissolved oxygen, while heat speeds up fish metabolism so they need more — a double hit that stresses or kills aquatic life. No substance is added; the pollutant is heat itself.