Environmental BioTechnologies, Inc.

Landfarming

The Problem

Significant quantities of material contaminated with elevated levels of petroleum hydrocarbons are produced year after year from operations such as oil well drilling, leaking underground storage tanks, surface spills, etc. The disposal of these contaminated materials can represent a significant disposal cost. Therefore, companies would prefer an economical, on site method for treating these heavily contaminated materials.

The Solution

Landfarming is the lowest cost approach to bioremediation of soil contaminated with oil. In this process, moisture is controlled, nutrients are provided, and there is some tilling to support aeration of the soil. Environmental BioTechnologies, Inc. (EBT) was contracted by a Canadian petroleum company to conduct a bench-scale biofeasibility study to determine the best bioprocess for treatment of petroleum contaminated horizontal well drill cuttings. EBT conducted a bioaugmented landfarming study to determine the feasibility of bioremediation. Figure 1 shows the results of this study.

Figure 1. Crude Oil Degradation Over Time with Three Treatments

EBT modeled a landfarming approach by placing a composite sample of the contaminated cuttings into a pan system which was not agitated, but mixed periodically at sampling times. The treatments included the following: 1) water only (control); 2) nitrogen (250 ppm N)+ phosphorus (25 ppm P) + inoculum (hydrocarbon degrading microorganisms); and 3) nitrogen + phosphorus + inoculum + surfactant (1% Cyanamer P-70). Moisture was maintained at approximately 13%, and the cuttings were sampled for Total Petroleum Hydrocarbons (TPH) at 0, 14, 28, 49 and 63 days.

Results from TPH analysis demonstrated that the most optimum treatment was with the addition of nutrients (N + P), an inoculum, and the surfactant, which achieved an average 38% reduction in the TPH concentration over the 63 day period (Figure 1). The addition of nutrients, and the inoculum demonstrated an average 28% reduction in the TPH concentration after 63 days, while the addition of water only to the contaminated cuttings did not produce a reduction in the TPH concentration after the 63 day period.

Results from this feasibility study proved landfarming to be a viable technology for treating heavily contaminated drill cuttings. Results demonstrated the necessity of bioaugmentation, nutrients, and a surfactant for the bioprocess, which significantly reduced the oil content of the cuttings from 16.5% to 9.8% oil in 63 days. This is an accelerated biodegradation rate of approximately 2% TPH/month.

Technology Application

Environmental BioTechnologies, Inc. (EBT) conducts laboratory and field studies which involve an assessment of the physical, chemical and biological parameters of a contaminated material. Bench-scale landfarming studies provide a relative index on the natural, unamended biodegradation rates vs. accelerated rates upon the addition of biostimulating agents. EBT provides technical and field support for the design and operation of bioremediation projects in the field.

To view an depiction of a landfarm, click here.

For more information concerning this technology, please feel free to contact Environmental BioTechnologies, Inc.

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Environmental BioTechnologies, Inc.
255C S. Guild Ave.
Lodi, CA 95240
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