Evaluación del potencial de biodegradación de hidrocarburos totales de petróleo (TPH) en suelos contaminados procedentes de Petrosantander (Colombia) Inc.

Abstract

Three soils with different petroleum contamination ages were studied in Camp Payoa, PetroSantander (Colombia) Inc. All soils presented fast infiltration and high permeability, characteristics of sandy soils. However, the water retention capacity and the porosity were affected by the hydrophobic character of the hydrocarbons. The carbon-nitrogen-phosphorus relation, the temperature and pH in the contaminated soils evaluated presented optimum values, adequate for bioremediation processes. The best results, in terms of hydrocarbon elimination (42.6%), were obtained when the soils were treated independently, mixed with clean soil, without both the addition of the selected and enlarged mixed microbial pool, and the pre-treatment with the bio-surfactant, which was composed by bacteria of the gender Serratia. The soil mixture composed by 50% of the soil with the oldest contamination event, and an equal 25% proportion of both medium and shortest contamination age soils, showed the total petroleum hydrocarbons (TPH) elimination percentage (28,6%), this soil underwent a one week pre-treatment process, and a mixed microbial pool addition at the beginning and middle of a three week biodegradation treatment period. An independent remediation treatment, without addition of both pre-treatment and microbial pool was conceived for the initial treatment design. However, considering that treating the soils in a mixed way avoids the transfer of contaminants to the clean soil, and that the best treatment, with mixed soils, reached a 3,0 % content of total hydrocarbons, also recommended by the Louisiana 29B regulation. This treatment was recommended combined with the best treatment conditions obtained.