Surface Energy Balance over Soils Remediated Using Thermal Desorption.

Accidental releases of petroleum products associated with energy production that occur on cropland severely inhibit production.  Thus, remediation techniques employed in agricultural areas must not only aim to decrease contaminant concentration, but they must also consider the viability of returning remediated soil to agricultural production.  Determining the energy balance at the soil surface is a useful way of examining the suitability of remediated soil for agronomic use.  The energy balance offers insight into soil water balances by determining the evaporative fluxes, as well as into soil temperature dynamics that play a vital role in seed germination and biological activity.  Ex situ thermal desorption (TD) is a remediation technique that is effective at reducing petroleum hydrocarbon concentrations in soil.  However, the alteration of soil physical properties associated with TD may have an impact on the surface energy balance.  This study assesses energy balance at the soil surface using a micro-Bowen ratio system over native non-contaminated soil, TD-treated soil, and a 1:1 mixture of native soil and TD treated soil.  Although soil colors and soil organic matter differ, net radiation does not vary between the treatments.  The variations in water content and bulk density are likely the cause of the differences in energy partitioning in TD treated soils and native soil.  The results of this study indicate that surface energy balances may be affected by TD, although the magnitude of effect is unclear.  These changes will impact the possibility of using TD as a remediation technique in future projects, since the soil water balances are crucial to long-term remediation success.