Groundwater Remediation System
Cornelsen Ltd. can offer both column strippers and the NEEP ShallowTray™ Air Strippers for groundwater remediation pump and treat systems. As the inventor of the ShallowTray™ stripper, these are the original design from which all other low profile, tray stripper have been copied. In addition our colleagues at Cornelsen Umwelttechnologie GmbH are authorised distributors for the QED EZ-Tray strippers. We can also offer vacuum strippers
The choice between column or ShallowTray™ depends on a number of factors, though frequently aesthetics and convenience may lead to selection of the ShallowTray™.
Air strippers are generally selected as an alternative to granular activated carbon (GAC). Where contaminant concentrations are expected to be quite high for a prolonged period, the quantity of carbon likely to be used may be very high and indeed the potential monthly costs may either be unsustainable or unpredictable. In these circumstances the cost of an air stripper is relatively fixed in terms of hire cost and/or power costs. Some uncertainty will remain as typically the off-gas will required treatment with vapour phase activated carbon or other technology. In this case a Biofilter can be an excellent choice due to the high moisture content of the air stripper off-gas.
- Highly efficient treatment process for volatile organic compounds which, subject to the specific contaminants may have a treatment efficiency in excess of 99.99%;
- Operational costs are generally easier to project compared to GAC although off-has GAC is generally still required;
Key benefits of ShallowTray™ strippers
- Compact with the ability to install within a steel shipping container;
- Particularly easy to maintain and clean
Air strippers work by injecting the untreated water through a spray nozzle either down a tall vertical column packed with proprietary open form polypropylene packing (which breaks up the flow path and creates a high surface area or, in the case of the ShallowTray™ Air stripper, down a series of flat shelves penetrated by small hoses. Fresh air is then blown through the stripper in a counter direction to the water flow at a considerably higher flow rate usually at least 50:1 or frequently 100:1 or more. The effect is to shatter the water into small particles increasing the contact area of the water particles to the air flow and thus the transfer of dissolved phase organics into the vapour phase wherein it is discharged to atmosphere or, more usually, through vapour treatment. As vapour phase activated carbon is considerably more efficient than aqueous phase activated carbon, this can and often does still make economic sense.
Be aware that off-gas from an air stripper generally has a high moisture content which leads to reduced efficiency of vapour phase activated carbon. Cornelsen Ltd. air stripper have key design features to both reduce moisture content and relative humidity without additional equipment.