A coal-fired power plant sprays limestone slurry through its flue gas. Which pollutant is this scrubber designed to remove?

Flue gas passes through an electrostatic precipitator with electrically charged collector plates. What does it remove?

A cement plant installs a baghouse, forcing its exhaust through large fabric bags. What pollutant is the baghouse targeting?

An industrial exhaust stream passes through activated carbon beds before release. Which pollutant class is the adsorber intended to remove?

A factory sends the exhaust from its paint-spraying booth to a thermal oxidizer. Which pollutant is this device primarily controlling?

A power plant injects ammonia into flue gas and passes it over a catalyst, converting pollutants to nitrogen and water. What does selective catalytic reduction target?

A diesel truck adds a ceramic filter that traps soot in its exhaust. Which pollutant does this control device remove?

A utility replaces its burners with ones that stage combustion to keep flame temperatures lower. Which pollutant does this mainly reduce?

Before exhaust enters a stack, it passes through a cyclone separator that spins the gas against the walls. What does it remove?

A catalytic converter is installed in a gasoline car's exhaust system. What is its main function?

What does a positive crankcase ventilation system do in a vehicle?

A vehicle's exhaust-gas-recirculation valve sends some exhaust back into the intake. How does this help control pollution?

A gasoline car stores fuel vapors in a charcoal canister and later sends them to the engine. What emissions does this system reduce?

Why does a modern gasoline vehicle use an oxygen sensor with a three-way catalytic converter?

Gasoline vapors that escape during refueling react with nitrogen oxides in sunlight. Which pollutant does this reaction form?

A diesel particulate filter becomes loaded with soot and then heats up to burn the stored soot. What is this process called?

Why must a car with a catalytic converter run on unleaded gasoline?

Which federal law requires EPA to set National Ambient Air Quality Standards for criteria pollutants?

Which pollutant is one of the six criteria pollutants regulated through National Ambient Air Quality Standards?

Under the Clean Air Act, what is the purpose of primary National Ambient Air Quality Standards?

A standard aims to limit haze and damage to crops, vegetation, and buildings. Under the Clean Air Act, what type of standard is this?

After EPA establishes an air-quality standard, what must a state submit to show how it will attain and maintain that standard?

A state does not submit an approvable plan for meeting a National Ambient Air Quality Standard. What may EPA issue under the Clean Air Act?

Which Clean Air Act program sets technology-based emission limits that a factory or power plant must meet when it is built or significantly modified?

The Clean Air Act requires national emission limits for motor vehicles, power plants, and factories. Which federal agency sets these limits?

Title IV of the 1990 Clean Air Act Amendments created a cap-and-trade program for sulfur dioxide from power plants. What is that program called?

Under the Acid Rain Program, what does the cap in cap and trade limit?

In the Acid Rain Program, one sulfur dioxide allowance authorizes a source to emit how much sulfur dioxide?

A power plant cuts its sulfur dioxide emissions below the allowances it holds. What can it do with the unused allowances?

A covered power plant emits 5,000 tons of sulfur dioxide in a year. What must it hold for Acid Rain Program compliance?