Bioremediation and Landfarming

Our Pretreatment Evaluation

Wilson typically approaches bioremediation projects in the following manner. First, existing site characterization data (if available) are reviewed to estimate the volume of contaminated material, characterize sludge, and evaluate site soil conditions. If data are unavailable or insufficient, site characterization becomes the first step of the process. Waste samples are characterized through organic and inorganic chemical analyses, and the waste’s toxicity to biological remediation agents is determined. On-site soils available for landfarming (and potential borrow soil sources) are evaluated to determine how their physical and chemical characteristics will affect the landfarming process.

Based on the results of these analyses, Wilson performs a pretreatment evaluation to:

  • Identify “target constituents” to be degraded in order to establish quantifiable performance criteria;
  • Evaluate treatment methods which have shown success in similar conditions;
  • Identify specific constraints present at the site (e.g., regulatory, geological, climatological, etc.) which may affect the unit’s performance; and
  • Determine the most cost effective biological approach which may include landfarming, slurry phase, fixed film reactors, etc.

Proven Through Bench-Scale Studies

For many “typical” remedial problems, Wilson has the experience to begin the remediation process immediately. For unique waste products or sludges, Wilson can perform bench-scale treatment studies on the sludge samples to determine the relative effectiveness of different remediation techniques. In addition to evaluating aeration techniques and nutrient additives, Wilson evaluates the benefits of complementary treatment strategies such as phase separation, which can greatly reduce the volume of hazardous material to be remediated. For example, oily sludges can often be separated into oil, water and soil phases through combinations of settling, heating, and the addition of diluents or polymers.

Once a treatment approach is proven through bench-scale studies, Wilson can develop pilot or demonstration-scale landfarm plots at the site to determine control parameters and peak loading rates under real-world conditions. During this phase, we also finalize conceptual design details including the landfarm facility’s size and configuration, the number and configuration of segregated cells, and the project’s water management facilities. Based on the performance of the pilot-scale study, Wilson makes specific recommendations for soil amendment, and initial loading rates for contaminants and treatment additives. Pilot-scale data also allow us to estimate the operation’s anticipated duration. Before turning the landfarm facility over to the operating contractor, Wilson prepares an operating manual, detailing:

  • Methods and equipment to be used for mixing and aeration;
  • Irrigation methods and parameters;
  • Monitoring methods and Indicating and Control Parameters; and
  • Criteria for Addition of nutrients.