Bioventing in a Residual Clayey Soil Contaminated with a Blend of Biodiesel and Diesel Oil

Abstract

Bioventing is an alternative technique to clean up contaminated soil. The purpose of this study is to assess the bioremediation of clayey soil contaminated with a blend of 80% diesel and 20% biodiesel (B20) using the bioventing and natural attenuation (NA) methods. The tests were carried out in bioreactors using soil contaminated with 4% of B20. Three airflow intensities (2, 4, and 6 L/min) were tested in three different airflow intervals (1 h every 24, 36, and 48 h). The contaminant degradation was determined by the contaminant’s residual fraction in the soil after 15, 30, 60, and 120 days. The highest degradation was 85% for bioventing and 64% for natural attenuation. The airflow intensities and airflow intervals showed no significant differences in the results. The use of the lowest airflow intensity (2 L/min) and the longest airflow interval (1-h application each 48 h) might be more economically viable for the application of bioventing as a remediation technique for residual clayey soils.