Chemical scrubbers are based on the physical absorption or the chemical reaction of gaseous contaminants present in the air flow; liquid and gaseous phases are countercurrent (in vertical scrubbers), and co-current (in horizontal scrubbers).
Contact between the two phases is achieved by specific packing material with a large surface area (structured or ring-type packing, depending on the application) which can work with large volumes of air and liquid, and less pressure loss.
Selective reagents are used in three stages: Acidic, basic, oxidizing.
