Laserfiche WebLink
In Situ Soil Venting <br /> S 4 <br /> Kty <br /> s. <br /> r- <br /> n <br /> .<rx <br /> s—or low <br /> e In soil venting, a vacuum well ideally suited for remediation of the foe, tia ons such permeability sons with high <br /> induces vapor flow through the unsaturated zone.The <br /> unsaturated soil zone to enhance contaminant must be relatively clay content. Venting wells are <br /> the natural rate of volatilization. volatile and exert a vapor pressure P wally eo toocreened throughdiameter <br /> More volatile compounds are PVC>.001 atm at the ambient contaminated region. They must <br /> removed first, and with time, temperature. Examples are <br /> residual contamination gradually gasoline and solvents such as be sealed properly to minimize <br /> becomes richer in the less volatile trichloroethylene. It is also possible "short-circuiting" airflow through <br /> compounds. Due to composition to remove less volatile compounds the should well <br /> casing. The vacuum be capable of 100 scfmuatp <br /> changes with time, effluent vapor by adding heat to the 40-200 inches H20 vacuum. <br /> concentrations and mass removal contaminated zone.The soil Usually vapor flow rates are >20 <br /> rates decrease with time. By should also be relatively <br /> permeable to airflow. A cfm from each well. A surface <br /> adding air injection wells, covering pavement or clay) <br /> selectively screening venting permeability of more than one anmi (tarp, <br /> dor Is <br /> sands) is a good can minimize vertical air flow from <br /> wells, or by adding heat to the cy ( tY <br /> contaminated zone—by hot air, guideline.Typically, venting does the atmosphere. Information from <br /> steam or in situ radio-frequency not efficiently remediate soils Shell Remediation Workshop <br /> dbook.l <br /> heating—the soil venting process contaminated with heavy HanWrite in 636 for more information. <br /> can be optimized. Soil venting is compounds such as crude oil or jet <br /> 58 December 1992 Soils <br />