BIOREMEDIATION OF HYDROCARBON CONTAMINATED SOILS THROUGH BIOSTIMULATION WITH SEWAGE SLUDGE - PILOT SCALE EXPERIMENTATION

Abstract

In the last decade, Bolivia has consolidated its position as one of the main producers of hydrocarbons and their derivatives, but due to hydrocarbon activities, large oil spills have occurred throughout the country, affecting the flora, fauna, soil and water in different regions. Soil alterations caused by oil spills and/or its derivatives, caused accidentally or by bad practices, affect the physicochemical and biological properties of the soil, irremediably degrading it. The objective was to evaluate in a pilot scale experiment, the results of the use of sewage sludge in the bioremediation process of soils contaminated with hydrocarbons and/or their derivatives. The experiment lasted 90 days and consisted of 7 plots of contaminated soil to which stabilized sludge was added at concentrations of 0%, 30%, 50% and 70%, all with a duplicate except for the 0% treatment. Total heterotrophs, nitrates, phosphates and TPH were evaluated monthly in each plot. The results were satisfactory in terms of TPH removal, especially in the plot containing 30% sewage sludge and 70% contaminated soil; this plot obtained a minimum of 42.9% removal of the contaminant.