VOC Evaporation

[remede]

I am trying to determine the approach to take to calculate the volume of air required to aerate hydrocarbon contaminated soil so as to transfer the hydrocarbons into the airstream (ambient conditions). This will be done ex-situ in an enclosed environment. The process will be continuous, not batch. The concentration of hydrocarbons (C2 to C20)are known in terms of ppm. Secondly, because the vapour/air stream will be contained consideration must be made for LEL and UEL. Any thoughts on how to proceed?

 

[mdszj]

If you can do treatability tests you may be able to take batches of the soil and aerate the batches at a given flow rate for varying amounts of time (for example, x cfm/unit soil for 1 day, 2 days, etc) or at varying rates for a given amount of time (example, x cfm/unit soil, 2x cfm/unit soil, 3x cfm/unit soil, etc). In other words, in such a way that you know how much air you put through the soil batch when you are done.

After doing the tests you could test each batch of soil for hydrocarbons to see the extent of reduction in hydrocarbon concentration. This should give at least a ballpark figure of aeration required.

ANother attack might be to call a vendor of this service (soil vapor extraction). They may have spreadsheets that can be plugged in to crank out the answers.

 

[dicksewerrat]

Are you going to pump the 'used' air away or leave in the bldg? Or store in pressurized tanks? I don't understand the 'contained' reference.

 

[dirtguy4]

Why don't you install several large air fans/vents, at either end of the building. The installation of these systems are pretty inexpensive and the more the better. Keep in mind you will not only have to supply enough oxygen to remediate your soil, but there could be some pretty serious concerns on safety with respect gassing of people accidentally entering your enclosed building. Not enough oxygen will put a man down very quickly and can have some very long term health effects.

 

[soilstuffer]

Quick thought, you may need some kind of air stream cleaning technology prior to discharge of the air stream to atmosphere. This could be achieved by some kind og thermal destruction or by using activated carbon depending on the size of your operation.