What Does Air Stripping Mean?
Air stripping refers to the process by which volatile contaminants are transferred from an aqueous solution to the air. The contaminants in the form of vapor are removed from the solution but not destroyed and can be treated using adsorption, oxidation or incineration.
The process involves exposing a large surface area of wastewater to the air, promoting the transfer of contaminants from the liquid to the gaseous phase. Volatile compounds have low aqueous solubility and high vapor pressure.
Trenchlesspedia Explains Air Stripping
Air stripping is conducted in a packed tower consisting of a cylindrical drum. At the top is a liquid inlet, and distributor; at the bottom is a gas inlet, and distributing space; and a supported mass of inert packing in the tower.
The air stripping tower packs a number of trays in a small chamber to maximize the contact area of water with air. Water is pumped to the top of the tower and allowed to flow down over the inert packing.
Air is pumped from the bottom of the tower. As water and air meet, the volatile organic compounds (VOCs) and ammonia are stripped out of the water into the air stream. Contaminated water with VOC or semi-volatile concentration greater than 0.01% cannot be treated by air stripping.
Pollutants with high Henry's law coefficient such as BTEX (benzene, toluene, ethylbenzene, and xylene) compounds and solvents such as trichloroethylene and tetrachloroethylene are easily and economically stripped from the water.
Stripping works best at warm temperatures.