"Pump and treat" technology is based on extracting contaminated water and treating it ex situ. The contaminated water goes into a water purification tower. In the tower there are plastic dropforming inserts. The water flows down the tower, while the fans blowing air into the system from below.
A packed column air stripper consists of a cylindrical column that contains a water distribution system packed with an air distributor. Contaminated water is distributed at the top of the column and flows down through the packing material. At the same time, air, introduced at the bottom of the column flows upward through the packing material. The purpose of the packing material is to provide greater surface area and impede the flow of both the air and water. As water and air make contact, volatile organic chemicals are transferred from the water to the air and are carried up while the clean water passes through the bottom. Once at the top of the stripper the contaminated air can be sent to another treatment process
and released once the necessary emissions have been met. While at the bottom of the tank the clean water will generally be released and remain as surface water or can be pumped down into an aquifer.
The essence of the method is that the pollution is transferred from the water into the air. Thus, the contaminated ion of the outgoing water is reduced or even eliminated. Efficiency can be increased by adding enzyme. The purified water injected back can dissolve the contamination from the soil. So the soil can also be cleaned. Contaminated air leaves the system through a filter. The filter is activated carbon.
The type of contamination determines the type of plastic drop-forming inserts used. The extent and concentration of pollution determine the number of towers to be used. For certain pollutants, efficiency can be increased by sedimentation pools. The efficiency of the technology is usually above 90%.