Air strippers are used for the removal of volatile organic compounds (VOC), gasoline range organics (GRO) and chlorinated organic compounds from water. The process involves high air to water contact by forcing air through contaminated process water, groundwater or surface water which allows the volatile contaminants to strip out of the liquid stream. The air stream from this process is then treated with vapor phase carbon vessels, an oxidizer or allowed to discharge into the atmosphere if below discharge regulations.
H2K Technologies Packed Tower Air Strippers are optimal for processing large quantities of water impacted by VOCs. Compared to our diffused and stacked tray air strippers, the tower air stripper has the highest process capacity. The aerator column is filled with polypropylene packing media, designed for either random packing or structured packing. The packing provides a large air/water contact area to strip volatile compounds from water. Vapors are discharged through the top of the tower to atmosphere or plumbed to an oxidizer or vapor phase carbon vessels for further treatment. Treated water is collected at the base of the tank for gravity drain or pump out. Packed tower air strippers provide efficient use of air with a lower air/water ratio and lower pressure drop with a large treatment cross section in the tower. Portable towers, with a mobile steel skid base are available.
For information on air stripping in environments with high solids loading, view our page for the DTA Series air stripper.
Trihalomethane (THM) removal (bromoform, chloroform, fluoroform, et al)
Hydrogen Sulfide removal (H2S removal)
Chlorinated compound removal
De-gasification (CO2 removal)
Bulk water processing: Packed tower air strippers are the best choice for processing large amounts of water in a municipal or industrial environment when solid loading is low. Towers can be designed with up to 12’ diameter, each tower having the ability to process 4,000 GPM. The internal media is chosen to provide a large air/water interface while providing less restriction to airflow through the tower. The blower requires a small discharge pressure (<10 “wc) to push through the treatment area, which translates to reduced energy cost with smaller blower motors.
Small treatment footprint: When height is less of a consideration, packed column air strippers are a great choice to reduce the footprint of the system. Towers can be constructed to heights up to 50 feet, which can greatly reduce the ground space for adequate water treatment. Towers can be designed with catwalks/mezzanines and OSHA-compliant ladder & rail systems to service all parts of a tower. When mobility is a consideration, portable towers are available. We design mobile systems with a portable steel base for easy transport.
The sizing of air strippers is based on several parameters.
Henry’s law constant of contaminants: Henry’s constant is a property of a compound which tells how easily a compound will evaporate or strip out of the water flow. This value changes with temperature, and can vary greatly between different compounds or different combinations of compounds. In general, the strippability of a compound increases with lower values of Henry’s constant.
Concentration of contaminants: Air strippers are able to remove a certain percentage of each contaminant at a given flow rate. In general, the higher the concentration of a given contaminant, the larger the air stripper will need to be to treat it effectively to meet discharge limits.
Process flow rate: As the flow rate of the water through the system increases, the residence time is decreased. Applications with higher flow rates require larger air strippers.
Application of discharge water and treatment limits: The final destination of the treated water will affect the required size of the air stripper. In general, stricter discharge limits (such as municipal or drinking water applications) require a larger air stripper in order to effectively treat the process flow.
Municipal water treatment
This system was included as part of an upgrade of a municipal water supply station. A 10’ diameter tower was used with a 15,000 CFM centrifugal blower to treat bromoform, chloroform, and other Volatile organic chemicals. This system included an integrated controls system with SCADA.
Packed tower humidifier
This dual-tower system was designed for a corrosion resistant desalinization process and evaporation of brackish water. This was optimized by utilizing a heat exchanger to transfer energy from the condensing water vapor to the incoming water source.Special care was taken in selecting equipment compatible with high salinity brine water, which included custom pumps, instruments, and piping.
Municipal water treatment
This packed column air stripper was designed for treatment of chlorinated compounds from municipal water supply. A 10’ diameter tower with a service catwalk was installed for treatment of DCA in a contaminated plume. This unit was installed to minimize floor space and exited through the roof of the treatment building.