Biodegradación aerobia de fracciones de hidrocarburos provenientes de la actividad petrolera en un suelo de la región Patagonia Norte, Argentina

Abstract

Recent techniques for assessing hydrocarbon contaminated sites are mainly based on risk analysis methodology. The effects of chemicals present in contaminated sites on the human health and the ecosystem are usually estimated as the addition of individual risks. In this sense, the hydrocarbon concentration is a relevant data. Bioremediation is a sustainable technology that accelerates the full or partial degradation of petroleum in contaminated soils and it shows a suitable cost-benefit ratio over other remediation methods. This work describes a laboratory scale study of the degradation rate for petroleum fractions by the incorporation of “biosolids” (sewage sludge) in an oil contaminated Patagonian soil. The determination of the total hydrocarbon concentration and the count of microorganisms in soil were performed both at the beginning and the end of the bioremediation process. The hydrocarbon degradation was analyzed at regular intervals during the study. The observed results showed that alkanes and lower molecular weight aromatic hydrocarbon concentrations were negligible after 14 days of treatment. The heavy hydrocarbon fraction, considered recalcitrant to biodegradation, was also significantly reduced during the biodegradation process. Since heavy hydrocarbons have low volatility and scarse migration by leaching, the observed decrease indicates that heavy hydrocarbon elimination could be mainly due to the native microorganism activity in the north Patagonian soils. Comparison with conventional treatment indicates that addition of “biosolids” enhances hydrocarbon remediation and that the biodiversity of microorganisms in soils is an important factor in achieving significant petroleum degradation.