The purpose of the plant is to dry the gas and remove impurities.

The stalks are then boiled in the town to remove impurities.

The juice was then heated and lime added to remove impurities.

This is to steam the face and open up the pores to further remove impurities from the skin.

Large quantities of water are frequently needed to remove impurities from coal at the mine.

Their process used heat to remove impurities from silicon.

So that is my question, "How does soil remove impurities from water?"

This process helped remove impurities and even out the carbon content of the steel.

Electrorefining uses a similar process to remove impurities from a metal.

Chemical reactions are often used to remove impurities of particular types.