Type of gas:
1. Type of technology
Wet collection / absorption.
2. Contaminants which can be removed
Water solubile substances.
3. Emission limits possible
Collection efficiencies exceeding 97% can be achieved.
4. Description of the equipment and/or process
Wet collectors or scrubbers represent the oldest and simplest system of cleaning a contaminated airborne flow.
The principle of operation consists in conveying the contaminated air into a chamber. Inside this chamber, thanks to suitable and widely differing technologies, an intimate contact takes place between the air and a certain quantity of water so that contaminants are transferred from the air into the water to the extent as to allow direct discharge of the air into the atmosphere with contaminant concentration within the allowable limits for the cleaned air.
Downstream to the scrubber-based air cleaning processes, by-products are normally to be found such as sludge that require disposal in accordance with public health and environmental concerns.
The sludge should first be submitted to dewatering, then compacted to make it suitable for transportation followed (if not toxic in nature) by burying in authorized waste disposal sites; if not, they are disposed of or incinerated in plants suitably equipped for such purposes. The quickness of air-water interaction and percentage of contaminating substances transferred from the air into the water are strongly conditioned both by the technology applied and the type of design and construction of the wet collector chosen.