Using Humalite-Derived Humic Products to Mobilize Soil- Adsorbed Hydrocarbons and Enhance Natural Attenuation

+ Author to whom correspondence should be directed. Residual hydrocarbons adsorbed to the soil present challenges for remediation due to the difficulty in physically removing the residual product and the associated time and cost requirements to do so. When the material is found to be fully sorbed to the soil, and virtually absent in the groundwater, traditional methods of treatment, such as pump-and-treat, are of limited utility. During historical groundwater monitoring events at an abandoned oil battery site, F2 and F3 hydrocarbons and PAHs have been found in the groundwater in the immediate area of what has been potentially identified as a former flare pit. The presence of deep earth metals, including lead, cadmium and selenium, indicates that impacted groundwater extends some distance downgradient of the flare pit area. While these deep earth metals are found in the downgradient groundwater, hydrocarbons are not observed, indicating that natural attenuation of the hydrocarbons is likely occurring. The remaining hydrocarbons (TEH, C8 to C40) are likely sorbed to the soil within the impacted area. Research is ongoing on the effectiveness of humic product injection into groundwater in an effort to increase the solubility of hydrophobic organic contaminants. The humic acid products are used as flushing agents to increase the concentration of some hydrophobic organic contaminants in the aqueous phase, in order to mobilize (desorb) the organic compounds from the soil and make them more available for biodegradation. Early results seem to indicate that the introduction of humic products into the groundwater of our site have been successful in mobilizing sorbed hydrocarbons into the groundwater where they will be more amenable to treatment through either traditional ex-situ methods or monitored natural attenuation and biodegradation