Aeration, also called air-stripping, mixes water with air to volatilize (or vaporize) certain organic contaminants. This technology is appropriate for removal of most volatile organic chemicals (such as hydrogen sulfide, hydrogen cyanide, ammonia, etc..) and certain pesticides. It does not remove inorganic chemicals (heavy metals), bacteria, viruses or cysts.
Packed tower aeration (PTA) is a waterfall aeration process that trickles raw water over a medium within a cylinder to mix water with air. The medium is usually composed of numerous hard plastic spheroid or box-type shapes, configured for maximum surface area. This medium is designed to break the water into tiny droplets, a process enhanced by the introduction of air blown from underneath the medium in the tower. As the air passes the water droplets, the organic contaminants are volatilized or “stripped” from the water and carried into the atmosphere. The rate at which the volatile organic chemicals can be efficiently removed by air stripping process, is highly dependent on pH of water as medium, on the surface area of the stripping tower, the quantity of treated water and the amount of volatile chemicals in the water.