Remediation of Soils Impacted with Heavy and Weathered Crude Oil: The Venezuelan Experience

Abstract:

Background/Objectives. The most widespread technology used to remediate crude oil impacted soils in Venezuela has been what we call “conventional” bioremediation, ie, the mineralization of the readily biodegradable oil fractions through stimulation of native microorganisms. However, the vast majority of Venezuelan crude oil reserves correspond to non-mineralizable oils; that is, oil of about or less than 10 oAPI. In addition, according to the current inventories, there are more than 9,000 open earth pits and an undetermined but large area impacted with highly weathered crude oil. Therefor, oily drilled cuttings and impacted soils and pits must be treated using innovative technologies, other than “conventional” bioremediation, in order to meet local regulations at a reasonable cost and with minimum environmental impact. The objective of this paper is to present the lab and field results, as well as the current tendencies and approaches that we are using in Venezuela for drilled cuttings treatment and the remediation of heavy and/or weathered oil impacted soils. Approach/Activities. In humid and warm sites, the lightest fractions of heavy crude oil, if present, are rapidly degraded and toxicity is significantly reduced or even eliminated due to natural attenuation or after a simple landfarming process. The recalcitrant residue, which sometimes amounts to more than 70% wt of the original oil, remains an environmental problem since its hydrophobicity reduces water retention capacity and affects soil exchange properties. Common technologies like thermal desorption, soil washing, incineration or treatment in cement kilns, if applicable, are very expensive …

Año de publicación:

2014

Keywords:

Fuente:

google