In dry and semi-dry purification procedures, lime is used for its absorption qualities of acid pollutants and heavy metals contained in gaseous effluents.

In the wet procedures, the lime is added to the gas column, or to the neutralization of the aqueous effluents in the washing tower.

Lime is the most suitable decontaminant due to its high performance, low cost and easy handling. The high specific surface area, porosity and particle size are very important characteristics for these purposes.