Which of the following are used to remove some gaseous pollutants?

Scrubbers remove sulphur dioxide, nitrogen oxides, and other harmful gases from industrial exhaust streams. Electrostatic precipitators are used to remove particulates.
One common type of scrubber is a wet scrubber, in which the exhaust gas is passed through a tower or chamber filled with the liquid (often water), which captures the pollutants and removes them from the air. The liquid solution can be designed to react with specific pollutants, neutralising them or turning them into less harmful compounds.