MEDALL, SHELDON E., and ADAM P. ZIPP, Toxic Technology, Inc., Costa Mesa, CA

ABSTRACT: Advancing Soil Bioremediation

Significant economic savings can be realized by using the combination of mechanical shredding, spray systems, and inclusion of bacteria and biocatalyst to actively bioremediate contaminated soils. The procedure involves pulverizing soil in a shredder and spraying the soil with liquid enriched with microbes and nutrients as it is conveyed to an exit ramp. The process works by greatly increasing the surface area of materials to be cleaned, thereby facilitating the aerobic environment for the bacteria to degrade the hydrocarbons.

This procedure works for both clay and sandy soils, and the shredder is capable of separating rock from the processed materials. Biodegradation is usually completed to acceptable EPA limits within two to four weeks as opposed to the longer term required for other remediation techniques. Additionally, the cost for performing the cleanup ranges between $40 and $50 per cubic yard. This can represent a savings of one-half to two-thirds of the cost that other methods of cleanup require because of its simplicity, speed, and ease in verification.

Using our patented technique of nuclear moderation with headspace vapor analysis, monitoring the rate of biodegradation is also facilitated. Under some circumstances, the treated soil can be compacted directly into the excavated area after biotreatment. This allows the bacteria to continue their degradation of the hydrocarbons while the property can be put in use as soon as the ground surface is restored.

AAPG Search and Discovery Article #90992©1993 AAPG Pacific Section Meeting, Long Beach, California, May 5-7, 1993.