These systems can have 2 or 3 washing stages, and different reactive are dosed to the columns according to the characteristics and the origin of the odours to be removed. The chemical scrubber is the most common system for the deodorizing of air coming from screening, pre-treatment, sludge dewatering and sludge thickening in waste water treatment plants.

Selective reactive are used in several stages:

· Acid
· Basic
· Oxidizing

The system is based in dilution, neutralization and chemical oxidation processes, which transfer the odorous compounds to a liquid phase.

The chemical scrubber is generally used for high flow rates, and when high performances are required.

SEE MORE PHOTOS